NativeScript Vue — Date Picker, Frame, HtmlView, and Images

Vue is an easy to use framework for building front end apps.

NativeScript is a mobile app framework that lets us build native mobile apps with popular front end frameworks.

In this article, we’ll look at how to build an app with NativeScript Vue.

DatePicker

NativeScript Vue comes with a date picker component.

To use it, we add:

#javascript

What is GEEK

Buddha Community

EasyMDE: Simple, Beautiful and Embeddable JavaScript Markdown Editor

EasyMDE - Markdown Editor 

This repository is a fork of SimpleMDE, made by Sparksuite. Go to the dedicated section for more information.

A drop-in JavaScript text area replacement for writing beautiful and understandable Markdown. EasyMDE allows users who may be less experienced with Markdown to use familiar toolbar buttons and shortcuts.

In addition, the syntax is rendered while editing to clearly show the expected result. Headings are larger, emphasized words are italicized, links are underlined, etc.

EasyMDE also features both built-in auto saving and spell checking. The editor is entirely customizable, from theming to toolbar buttons and javascript hooks.

Try the demo

Quick access

• EasyMDE - Markdown Editor
  • Quick access
  • Install EasyMDE
  • How to use
    • Loading the editor
    • Editor functions
  • Configuration
    • Options list
    • Options example
    • Toolbar icons
    • Toolbar customization
    • Keyboard shortcuts
  • Advanced use
    • Event handling
    • Removing EasyMDE from text area
    • Useful methods
  • How it works
  • SimpleMDE fork
  • Hacking EasyMDE
  • Contributing
  • License

Install EasyMDE

Via npm:

npm install easymde

Via the UNPKG CDN:

<link rel="stylesheet" href="https://unpkg.com/easymde/dist/easymde.min.css">
<script src="https://unpkg.com/easymde/dist/easymde.min.js"></script>

Or jsDelivr:

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/easymde/dist/easymde.min.css">
<script src="https://cdn.jsdelivr.net/npm/easymde/dist/easymde.min.js"></script>

How to use

Loading the editor

After installing and/or importing the module, you can load EasyMDE onto the first textarea element on the web page:

<textarea></textarea>
<script>
const easyMDE = new EasyMDE();
</script>

Alternatively you can select a specific textarea, via JavaScript:

<textarea id="my-text-area"></textarea>
<script>
const easyMDE = new EasyMDE({element: document.getElementById('my-text-area')});
</script>

Editor functions

Use easyMDE.value() to get the content of the editor:

<script>
easyMDE.value();
</script>

Use easyMDE.value(val) to set the content of the editor:

<script>
easyMDE.value('New input for **EasyMDE**');
</script>

Configuration

Options list

• autoDownloadFontAwesome: If set to true, force downloads Font Awesome (used for icons). If set to false, prevents downloading. Defaults to undefined, which will intelligently check whether Font Awesome has already been included, then download accordingly.
• autofocus: If set to true, focuses the editor automatically. Defaults to false.
• autosave: Saves the text that's being written and will load it back in the future. It will forget the text when the form it's contained in is submitted.
  • enabled: If set to true, saves the text automatically. Defaults to false.
  • delay: Delay between saves, in milliseconds. Defaults to 10000 (10 seconds).
  • submit_delay: Delay before assuming that submit of the form failed and saving the text, in milliseconds. Defaults to autosave.delay or 10000 (10 seconds).
  • uniqueId: You must set a unique string identifier so that EasyMDE can autosave. Something that separates this from other instances of EasyMDE elsewhere on your website.
  • timeFormat: Set DateTimeFormat. More information see DateTimeFormat instances. Default locale: en-US, format: hour:minute.
  • text: Set text for autosave.
• autoRefresh: Useful, when initializing the editor in a hidden DOM node. If set to { delay: 300 }, it will check every 300 ms if the editor is visible and if positive, call CodeMirror's refresh().
• blockStyles: Customize how certain buttons that style blocks of text behave.
  • bold: Can be set to ** or __. Defaults to **.
  • code: Can be set to ``` or ~~~. Defaults to ```.
  • italic: Can be set to * or _. Defaults to *.
• unorderedListStyle: can be *, - or +. Defaults to *.
• scrollbarStyle: Chooses a scrollbar implementation. The default is "native", showing native scrollbars. The core library also provides the "null" style, which completely hides the scrollbars. Addons can implement additional scrollbar models.
• element: The DOM element for the textarea element to use. Defaults to the first textarea element on the page.
• forceSync: If set to true, force text changes made in EasyMDE to be immediately stored in original text area. Defaults to false.
• hideIcons: An array of icon names to hide. Can be used to hide specific icons shown by default without completely customizing the toolbar.
• indentWithTabs: If set to false, indent using spaces instead of tabs. Defaults to true.
• initialValue: If set, will customize the initial value of the editor.
• previewImagesInEditor: - EasyMDE will show preview of images, false by default, preview for images will appear only for images on separate lines.
• imagesPreviewHandler: - A custom function for handling the preview of images. Takes the parsed string between the parantheses of the image markdown ![]( ) as argument and returns a string that serves as the src attribute of the <img> tag in the preview. Enables dynamic previewing of images in the frontend without having to upload them to a server, allows copy-pasting of images to the editor with preview.
• insertTexts: Customize how certain buttons that insert text behave. Takes an array with two elements. The first element will be the text inserted before the cursor or highlight, and the second element will be inserted after. For example, this is the default link value: ["[", "](http://)"].
  • horizontalRule
  • image
  • link
  • table
• lineNumbers: If set to true, enables line numbers in the editor.
• lineWrapping: If set to false, disable line wrapping. Defaults to true.
• minHeight: Sets the minimum height for the composition area, before it starts auto-growing. Should be a string containing a valid CSS value like "500px". Defaults to "300px".
• maxHeight: Sets fixed height for the composition area. minHeight option will be ignored. Should be a string containing a valid CSS value like "500px". Defaults to undefined.
• onToggleFullScreen: A function that gets called when the editor's full screen mode is toggled. The function will be passed a boolean as parameter, true when the editor is currently going into full screen mode, or false.
• parsingConfig: Adjust settings for parsing the Markdown during editing (not previewing).
  • allowAtxHeaderWithoutSpace: If set to true, will render headers without a space after the #. Defaults to false.
  • strikethrough: If set to false, will not process GFM strikethrough syntax. Defaults to true.
  • underscoresBreakWords: If set to true, let underscores be a delimiter for separating words. Defaults to false.
• overlayMode: Pass a custom codemirror overlay mode to parse and style the Markdown during editing.
  • mode: A codemirror mode object.
  • combine: If set to false, will replace CSS classes returned by the default Markdown mode. Otherwise the classes returned by the custom mode will be combined with the classes returned by the default mode. Defaults to true.
• placeholder: If set, displays a custom placeholder message.
• previewClass: A string or array of strings that will be applied to the preview screen when activated. Defaults to "editor-preview".
• previewRender: Custom function for parsing the plaintext Markdown and returning HTML. Used when user previews.
• promptURLs: If set to true, a JS alert window appears asking for the link or image URL. Defaults to false.
• promptTexts: Customize the text used to prompt for URLs.
  • image: The text to use when prompting for an image's URL. Defaults to URL of the image:.
  • link: The text to use when prompting for a link's URL. Defaults to URL for the link:.
• uploadImage: If set to true, enables the image upload functionality, which can be triggered by drag and drop, copy-paste and through the browse-file window (opened when the user click on the upload-image icon). Defaults to false.
• imageMaxSize: Maximum image size in bytes, checked before upload (note: never trust client, always check the image size at server-side). Defaults to 1024 * 1024 * 2 (2 MB).
• imageAccept: A comma-separated list of mime-types used to check image type before upload (note: never trust client, always check file types at server-side). Defaults to image/png, image/jpeg.
• imageUploadFunction: A custom function for handling the image upload. Using this function will render the options imageMaxSize, imageAccept, imageUploadEndpoint and imageCSRFToken ineffective.
  • The function gets a file and onSuccess and onError callback functions as parameters. onSuccess(imageUrl: string) and onError(errorMessage: string)
• imageUploadEndpoint: The endpoint where the images data will be sent, via an asynchronous POST request. The server is supposed to save this image, and return a JSON response.
  • if the request was successfully processed (HTTP 200 OK): {"data": {"filePath": "<filePath>"}} where filePath is the path of the image (absolute if imagePathAbsolute is set to true, relative if otherwise);
  • otherwise: {"error": "<errorCode>"}, where errorCode can be noFileGiven (HTTP 400 Bad Request), typeNotAllowed (HTTP 415 Unsupported Media Type), fileTooLarge (HTTP 413 Payload Too Large) or importError (see errorMessages below). If errorCode is not one of the errorMessages, it is alerted unchanged to the user. This allows for server-side error messages. No default value.
• imagePathAbsolute: If set to true, will treat imageUrl from imageUploadFunction and filePath returned from imageUploadEndpoint as an absolute rather than relative path, i.e. not prepend window.location.origin to it.
• imageCSRFToken: CSRF token to include with AJAX call to upload image. For various instances like Django, Spring and Laravel.
• imageCSRFName: CSRF token filed name to include with AJAX call to upload image, applied when imageCSRFToken has value, defaults to csrfmiddlewaretoken.
• imageCSRFHeader: If set to true, passing CSRF token via header. Defaults to false, which pass CSRF through request body.
• imageTexts: Texts displayed to the user (mainly on the status bar) for the import image feature, where #image_name#, #image_size# and #image_max_size# will replaced by their respective values, that can be used for customization or internationalization:
  • sbInit: Status message displayed initially if uploadImage is set to true. Defaults to Attach files by drag and dropping or pasting from clipboard..
  • sbOnDragEnter: Status message displayed when the user drags a file to the text area. Defaults to Drop image to upload it..
  • sbOnDrop: Status message displayed when the user drops a file in the text area. Defaults to Uploading images #images_names#.
  • sbProgress: Status message displayed to show uploading progress. Defaults to Uploading #file_name#: #progress#%.
  • sbOnUploaded: Status message displayed when the image has been uploaded. Defaults to Uploaded #image_name#.
  • sizeUnits: A comma-separated list of units used to display messages with human-readable file sizes. Defaults to B, KB, MB (example: 218 KB). You can use B,KB,MB instead if you prefer without whitespaces (218KB).
• errorMessages: Errors displayed to the user, using the errorCallback option, where #image_name#, #image_size# and #image_max_size# will replaced by their respective values, that can be used for customization or internationalization:
  • noFileGiven: The server did not receive any file from the user. Defaults to You must select a file..
  • typeNotAllowed: The user send a file type which doesn't match the imageAccept list, or the server returned this error code. Defaults to This image type is not allowed..
  • fileTooLarge: The size of the image being imported is bigger than the imageMaxSize, or if the server returned this error code. Defaults to Image #image_name# is too big (#image_size#).\nMaximum file size is #image_max_size#..
  • importError: An unexpected error occurred when uploading the image. Defaults to Something went wrong when uploading the image #image_name#..
• errorCallback: A callback function used to define how to display an error message. Defaults to (errorMessage) => alert(errorMessage).
• renderingConfig: Adjust settings for parsing the Markdown during previewing (not editing).
  • codeSyntaxHighlighting: If set to true, will highlight using highlight.js. Defaults to false. To use this feature you must include highlight.js on your page or pass in using the hljs option. For example, include the script and the CSS files like:
    <script src="https://cdn.jsdelivr.net/highlight.js/latest/highlight.min.js"></script>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/highlight.js/latest/styles/github.min.css">
  • hljs: An injectible instance of highlight.js. If you don't want to rely on the global namespace (window.hljs), you can provide an instance here. Defaults to undefined.
  • markedOptions: Set the internal Markdown renderer's options. Other renderingConfig options will take precedence.
  • singleLineBreaks: If set to false, disable parsing GitHub Flavored Markdown (GFM) single line breaks. Defaults to true.
  • sanitizerFunction: Custom function for sanitizing the HTML output of Markdown renderer.
• shortcuts: Keyboard shortcuts associated with this instance. Defaults to the array of shortcuts.
• showIcons: An array of icon names to show. Can be used to show specific icons hidden by default without completely customizing the toolbar.
• spellChecker: If set to false, disable the spell checker. Defaults to true. Optionally pass a CodeMirrorSpellChecker-compliant function.
• inputStyle: textarea or contenteditable. Defaults to textarea for desktop and contenteditable for mobile. contenteditable option is necessary to enable nativeSpellcheck.
• nativeSpellcheck: If set to false, disable native spell checker. Defaults to true.
• sideBySideFullscreen: If set to false, allows side-by-side editing without going into fullscreen. Defaults to true.
• status: If set to false, hide the status bar. Defaults to the array of built-in status bar items.
  • Optionally, you can set an array of status bar items to include, and in what order. You can even define your own custom status bar items.
• styleSelectedText: If set to false, remove the CodeMirror-selectedtext class from selected lines. Defaults to true.
• syncSideBySidePreviewScroll: If set to false, disable syncing scroll in side by side mode. Defaults to true.
• tabSize: If set, customize the tab size. Defaults to 2.
• theme: Override the theme. Defaults to easymde.
• toolbar: If set to false, hide the toolbar. Defaults to the array of icons.
• toolbarTips: If set to false, disable toolbar button tips. Defaults to true.
• direction: rtl or ltr. Changes text direction to support right-to-left languages. Defaults to ltr.

Options example

Most options demonstrate the non-default behavior:

const editor = new EasyMDE({
    autofocus: true,
    autosave: {
        enabled: true,
        uniqueId: "MyUniqueID",
        delay: 1000,
        submit_delay: 5000,
        timeFormat: {
            locale: 'en-US',
            format: {
                year: 'numeric',
                month: 'long',
                day: '2-digit',
                hour: '2-digit',
                minute: '2-digit',
            },
        },
        text: "Autosaved: "
    },
    blockStyles: {
        bold: "__",
        italic: "_",
    },
    unorderedListStyle: "-",
    element: document.getElementById("MyID"),
    forceSync: true,
    hideIcons: ["guide", "heading"],
    indentWithTabs: false,
    initialValue: "Hello world!",
    insertTexts: {
        horizontalRule: ["", "\n\n-----\n\n"],
        image: ["![](http://", ")"],
        link: ["[", "](https://)"],
        table: ["", "\n\n| Column 1 | Column 2 | Column 3 |\n| -------- | -------- | -------- |\n| Text     | Text      | Text     |\n\n"],
    },
    lineWrapping: false,
    minHeight: "500px",
    parsingConfig: {
        allowAtxHeaderWithoutSpace: true,
        strikethrough: false,
        underscoresBreakWords: true,
    },
    placeholder: "Type here...",

    previewClass: "my-custom-styling",
    previewClass: ["my-custom-styling", "more-custom-styling"],

    previewRender: (plainText) => customMarkdownParser(plainText), // Returns HTML from a custom parser
    previewRender: (plainText, preview) => { // Async method
        setTimeout(() => {
            preview.innerHTML = customMarkdownParser(plainText);
        }, 250);

        return "Loading...";
    },
    promptURLs: true,
    promptTexts: {
        image: "Custom prompt for URL:",
        link: "Custom prompt for URL:",
    },
    renderingConfig: {
        singleLineBreaks: false,
        codeSyntaxHighlighting: true,
        sanitizerFunction: (renderedHTML) => {
            // Using DOMPurify and only allowing <b> tags
            return DOMPurify.sanitize(renderedHTML, {ALLOWED_TAGS: ['b']})
        },
    },
    shortcuts: {
        drawTable: "Cmd-Alt-T"
    },
    showIcons: ["code", "table"],
    spellChecker: false,
    status: false,
    status: ["autosave", "lines", "words", "cursor"], // Optional usage
    status: ["autosave", "lines", "words", "cursor", {
        className: "keystrokes",
        defaultValue: (el) => {
            el.setAttribute('data-keystrokes', 0);
        },
        onUpdate: (el) => {
            const keystrokes = Number(el.getAttribute('data-keystrokes')) + 1;
            el.innerHTML = `${keystrokes} Keystrokes`;
            el.setAttribute('data-keystrokes', keystrokes);
        },
    }], // Another optional usage, with a custom status bar item that counts keystrokes
    styleSelectedText: false,
    sideBySideFullscreen: false,
    syncSideBySidePreviewScroll: false,
    tabSize: 4,
    toolbar: false,
    toolbarTips: false,
});

Toolbar icons

Below are the built-in toolbar icons (only some of which are enabled by default), which can be reorganized however you like. "Name" is the name of the icon, referenced in the JavaScript. "Action" is either a function or a URL to open. "Class" is the class given to the icon. "Tooltip" is the small tooltip that appears via the title="" attribute. Note that shortcut hints are added automatically and reflect the specified action if it has a key bind assigned to it (i.e. with the value of action set to bold and that of tooltip set to Bold, the final text the user will see would be "Bold (Ctrl-B)").

Additionally, you can add a separator between any icons by adding "|" to the toolbar array.

Name	Action	Tooltip Class
bold	toggleBold	Bold fa fa-bold
italic	toggleItalic	Italic fa fa-italic
strikethrough	toggleStrikethrough	Strikethrough fa fa-strikethrough
heading	toggleHeadingSmaller	Heading fa fa-header
heading-smaller	toggleHeadingSmaller	Smaller Heading fa fa-header
heading-bigger	toggleHeadingBigger	Bigger Heading fa fa-lg fa-header
heading-1	toggleHeading1	Big Heading fa fa-header header-1
heading-2	toggleHeading2	Medium Heading fa fa-header header-2
heading-3	toggleHeading3	Small Heading fa fa-header header-3
code	toggleCodeBlock	Code fa fa-code
quote	toggleBlockquote	Quote fa fa-quote-left
unordered-list	toggleUnorderedList	Generic List fa fa-list-ul
ordered-list	toggleOrderedList	Numbered List fa fa-list-ol
clean-block	cleanBlock	Clean block fa fa-eraser
link	drawLink	Create Link fa fa-link
image	drawImage	Insert Image fa fa-picture-o
table	drawTable	Insert Table fa fa-table
horizontal-rule	drawHorizontalRule	Insert Horizontal Line fa fa-minus
preview	togglePreview	Toggle Preview fa fa-eye no-disable
side-by-side	toggleSideBySide	Toggle Side by Side fa fa-columns no-disable no-mobile
fullscreen	toggleFullScreen	Toggle Fullscreen fa fa-arrows-alt no-disable no-mobile
guide	This link	Markdown Guide fa fa-question-circle
undo	undo	Undo fa fa-undo
redo	redo	Redo fa fa-redo

Toolbar customization

Customize the toolbar using the toolbar option.

Only the order of existing buttons:

const easyMDE = new EasyMDE({
    toolbar: ["bold", "italic", "heading", "|", "quote"]
});

All information and/or add your own icons

const easyMDE = new EasyMDE({
    toolbar: [
        {
            name: "bold",
            action: EasyMDE.toggleBold,
            className: "fa fa-bold",
            title: "Bold",
        },
        "italics", // shortcut to pre-made button
        {
            name: "custom",
            action: (editor) => {
                // Add your own code
            },
            className: "fa fa-star",
            title: "Custom Button",
            attributes: { // for custom attributes
                id: "custom-id",
                "data-value": "custom value" // HTML5 data-* attributes need to be enclosed in quotation marks ("") because of the dash (-) in its name.
            }
        },
        "|" // Separator
        // [, ...]
    ]
});

Put some buttons on dropdown menu

const easyMDE = new EasyMDE({
    toolbar: [{
                name: "heading",
                action: EasyMDE.toggleHeadingSmaller,
                className: "fa fa-header",
                title: "Headers",
            },
            "|",
            {
                name: "others",
                className: "fa fa-blind",
                title: "others buttons",
                children: [
                    {
                        name: "image",
                        action: EasyMDE.drawImage,
                        className: "fa fa-picture-o",
                        title: "Image",
                    },
                    {
                        name: "quote",
                        action: EasyMDE.toggleBlockquote,
                        className: "fa fa-percent",
                        title: "Quote",
                    },
                    {
                        name: "link",
                        action: EasyMDE.drawLink,
                        className: "fa fa-link",
                        title: "Link",
                    }
                ]
            },
        // [, ...]
    ]
});

Keyboard shortcuts

EasyMDE comes with an array of predefined keyboard shortcuts, but they can be altered with a configuration option. The list of default ones is as follows:

Shortcut (Windows / Linux)	Shortcut (macOS)	Action
Ctrl-'	Cmd-'	"toggleBlockquote"
Ctrl-B	Cmd-B	"toggleBold"
Ctrl-E	Cmd-E	"cleanBlock"
Ctrl-H	Cmd-H	"toggleHeadingSmaller"
Ctrl-I	Cmd-I	"toggleItalic"
Ctrl-K	Cmd-K	"drawLink"
Ctrl-L	Cmd-L	"toggleUnorderedList"
Ctrl-P	Cmd-P	"togglePreview"
Ctrl-Alt-C	Cmd-Alt-C	"toggleCodeBlock"
Ctrl-Alt-I	Cmd-Alt-I	"drawImage"
Ctrl-Alt-L	Cmd-Alt-L	"toggleOrderedList"
Shift-Ctrl-H	Shift-Cmd-H	"toggleHeadingBigger"
F9	F9	"toggleSideBySide"
F11	F11	"toggleFullScreen"

Here is how you can change a few, while leaving others untouched:

const editor = new EasyMDE({
    shortcuts: {
        "toggleOrderedList": "Ctrl-Alt-K", // alter the shortcut for toggleOrderedList
        "toggleCodeBlock": null, // unbind Ctrl-Alt-C
        "drawTable": "Cmd-Alt-T", // bind Cmd-Alt-T to drawTable action, which doesn't come with a default shortcut
    }
});

Shortcuts are automatically converted between platforms. If you define a shortcut as "Cmd-B", on PC that shortcut will be changed to "Ctrl-B". Conversely, a shortcut defined as "Ctrl-B" will become "Cmd-B" for Mac users.

The list of actions that can be bound is the same as the list of built-in actions available for toolbar buttons.

Advanced use

Event handling

You can catch the following list of events: https://codemirror.net/doc/manual.html#events

const easyMDE = new EasyMDE();
easyMDE.codemirror.on("change", () => {
    console.log(easyMDE.value());
});

Removing EasyMDE from text area

You can revert to the initial text area by calling the toTextArea method. Note that this clears up the autosave (if enabled) associated with it. The text area will retain any text from the destroyed EasyMDE instance.

const easyMDE = new EasyMDE();
// ...
easyMDE.toTextArea();
easyMDE = null;

If you need to remove registered event listeners (when the editor is not needed anymore), call easyMDE.cleanup().

Useful methods

The following self-explanatory methods may be of use while developing with EasyMDE.

const easyMDE = new EasyMDE();
easyMDE.isPreviewActive(); // returns boolean
easyMDE.isSideBySideActive(); // returns boolean
easyMDE.isFullscreenActive(); // returns boolean
easyMDE.clearAutosavedValue(); // no returned value

How it works

EasyMDE is a continuation of SimpleMDE.

SimpleMDE began as an improvement of lepture's Editor project, but has now taken on an identity of its own. It is bundled with CodeMirror and depends on Font Awesome.

CodeMirror is the backbone of the project and parses much of the Markdown syntax as it's being written. This allows us to add styles to the Markdown that's being written. Additionally, a toolbar and status bar have been added to the top and bottom, respectively. Previews are rendered by Marked using GitHub Flavored Markdown (GFM).

SimpleMDE fork

I originally made this fork to implement FontAwesome 5 compatibility into SimpleMDE. When that was done I submitted a pull request, which has not been accepted yet. This, and the project being inactive since May 2017, triggered me to make more changes and try to put new life into the project.

Changes include:

• FontAwesome 5 compatibility
• Guide button works when editor is in preview mode
• Links are now https:// by default
• Small styling changes
• Support for Node 8 and beyond
• Lots of refactored code
• Links in preview will open in a new tab by default
• TypeScript support

My intention is to continue development on this project, improving it and keeping it alive.

Hacking EasyMDE

You may want to edit this library to adapt its behavior to your needs. This can be done in some quick steps:

1. Follow the prerequisites and installation instructions in the contribution guide;
2. Do your changes;
3. Run gulp command, which will generate files: dist/easymde.min.css and dist/easymde.min.js;
4. Copy-paste those files to your code base, and you are done.

Contributing

Want to contribute to EasyMDE? Thank you! We have a contribution guide just for you!

---

Author: Ionaru
Source Code: https://github.com/Ionaru/easy-markdown-editor
License: MIT license

#react-native #react 

8 Popular Websites That Use The Vue.JS Framework

In this article, we are going to list out the most popular websites using Vue JS as their frontend framework.

Vue JS is one of those elite progressive JavaScript frameworks that has huge demand in the web development industry. Many popular websites are developed using Vue in their frontend development because of its imperative features.

This framework was created by Evan You and still it is maintained by his private team members. Vue is of course an open-source framework which is based on MVVM concept (Model-view view-Model) and used extensively in building sublime user-interfaces and also considered a prime choice for developing single-page heavy applications.

Released in February 2014, Vue JS has gained 64,828 stars on Github, making it very popular in recent times.

Evan used Angular JS on many operations while working for Google and integrated many features in Vue to cover the flaws of Angular.

“I figured, what if I could just extract the part that I really liked about Angular and build something really lightweight." - Evan You

#vuejs #vue #vue-with-laravel #vue-top-story #vue-3 #build-vue-frontend #vue-in-laravel #vue.js

Angular Datepicker：Angular13でDatepickerを使用する方法

Angular Materialは、 Web、モバイル、デスクトップで機能 する重要で最新のUIコンポーネントを備えた地上運用です。 

Angular Materialコンポーネントは、ブラウザーの移植性と互換性、デバイスの独立性、適切な機能低下などの最新のWebデザイン原則を維持しながら、魅力的なUIとUX、一貫性のある機能的なWebページ、およびWebアプリケーションを構築するのに役立ちます。

Angular Datepicker

Angular Datepickerは、テキスト入力またはカレンダーから日付を選択して日付を入力できる組み込みのマテリアルコンポーネントです。Angular Material Datepickerを使用すると、ユーザーはテキスト入力またはカレンダーから日付を選択して日付を入力できます。Material Datepickerは、連携して機能するいくつかのコンポーネントとディレクティブで構成されています。

これは、連携して機能するさまざまな角度コンポーネントとディレクティブで構成されています。まず、Angularをインストールする必要があります。 AngularCLIを使用して Angularをインストールしてい ます。

ステップ1：AngularCLIをインストールします。

次のコマンドを入力します。

npm install -g @angular/cli

次に、次のコマンドを使用してAngularプロジェクトを作成します。

 

ng new datepicker

ステップ2：他のライブラリをインストールします。

プロジェクトに移動し、次のコマンドを使用してhammerjs をインストールし ます。

npm install --save hammerjs

Hammer.jsはオプションの依存関係であり、いくつかのコンポーネントのタッチサポートに役立ちます。

次に、次のコマンドを使用してAngularMaterial と AngularAnimations をインストール します。

npm install --save @angular/material @angular/animations @angular/cdk

ここで、  angular.json ファイル内に hammerjs を含めます。このファイルはプロジェクトのルートにあります。

ステップ3：作成済みのテーマとマテリアルアイコンをインポートします。

Angular Materialには、いくつかの事前に作成されたテーマが付属しています。これらのテーマは、色と基本的なスタイリングを際立たせています。

利用可能な主なテーマは、 インディゴピンク、 ディープパープルアンバー、 パープルグリーン、 ピンク ブルーグレーです。

テーマをインポートするには、次のコードをグローバル styles.css ファイルに追加します。ファイルはsrc フォルダー内にあります。

@import '~@angular/material/prebuilt-themes/indigo-pink.css';

マテリアルデザインアイコンにアクセスして、 <mat-icon> コンポーネント で名前付きアイコンを使用 することもできます。

それらをプロジェクトにインポートする場合は、これをプロジェクトのルート index.html ファイルのheadセクションに追加できます。

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>Datepicker</title>
  <base href="/">

  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="icon" type="image/x-icon" href="favicon.ico">
  <link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
</head>
<body>
  <app-root></app-root>
</body>
</html>

ステップ4：カスタムマテリアルモジュールファイルを作成します。

src、>> app フォルダー内に、 material.module.ts というファイルを1つ作成 し、次のコードを追加します。

// material.module.ts

import { NgModule } from '@angular/core';
import { MatDatepickerModule } from '@angular/material';

@NgModule({
  imports: [
    MatDatepickerModule
  ],
  exports: [
    MatDatepickerModule
  ]
})

export class MaterialModule {}

MatDatepickerModule、MatNativeDateModule、 およびAngularDatepickerサンプル アプリに必要なその他のコンポーネントを インポートしました。

必要に応じて、将来的にコンポーネントを追加できます。

このファイルにはすべてのマテリアルコンポーネントを 簡単に含めることができるため、このファイルは独自に作成され、このファイルはapp.module.ts内にインポートされます。

// material.module.ts

import { NgModule } from '@angular/core';
import { MatDatepickerModule,
        MatNativeDateModule,
        MatFormFieldModule,
        MatInputModule } from '@angular/material';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';

@NgModule({
  imports: [
    MatDatepickerModule,
    MatFormFieldModule,
    MatNativeDateModule,
    MatInputModule,
    BrowserAnimationsModule
  ],
  exports: [
    MatDatepickerModule,
    MatFormFieldModule,
    MatNativeDateModule,
    MatInputModule,
    BrowserAnimationsModule
  ],
  providers: [ MatDatepickerModule ],
})

export class MaterialModule {}

ステップ5：App.module.tsファイルにMaterialModuleをインポートします。

app.module.ts ファイル内にMaterialModuleをインポートします。

// app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { MaterialModule } from './material.module';

import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    MaterialModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

また、最後に、app.component.html ファイル内にDatepickerHTMLコードを記述します。

<!-- app.component.html -->

<mat-form-field>
  <input matInput [matDatepicker]="picker" placeholder="Choose a date">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker></mat-datepicker>
</mat-form-field>

ファイルを保存し、ターミナルまたはcmdに移動して、AngularDevelopmentServerを起動します。

ng serve --open

ブラウザに移動すると、次の画像のようなものが表示されます。

ステップ6：日付ピッカーを入力に接続する

日付ピッカーは、テキスト入力とカレンダーポップアップで構成され、テキスト入力のmatDatePicker プロパティを介して接続されます。

<input [matDatepicker]="myDatepicker">
<mat-datepicker #myDatepicker></mat-datepicker>

オプションの日付ピッカートグルボタンが利用可能です。上記の例にトグルボタンを追加できます。

<input [matDatepicker]="myDatepicker">
<mat-datepicker-toggle [for]="myDatepicker"></mat-datepicker-toggle>
<mat-datepicker #myDatepicker></mat-datepicker>

<mat-form-field>の一部である入力でも同じように機能し、トグルボタンをマテリアル入力のプレフィックスまたはサフィックスとして簡単に使用できます。

<mat-form-field>
  <input matInput [matDatepicker]="myDatepicker">
  <mat-datepicker-toggle matSuffix [for]="myDatepicker"></mat-datepicker-toggle>
  <mat-datepicker #myDatepicker></mat-datepicker>
</mat-form-field>

ステップ7：カレンダーの開始ビューを設定する

 <mat-datepicker>の startViewプロパティを使用して、カレンダーを最初に開いたときに表示される外観を設定できます。月、 年、または 複数年に構成できます 。デフォルトでは、月表示を開始します。

カレンダーが開く月、年、または年の範囲は、最初に日付が現在選択されているかどうかを確認することによって決定され、選択されている場合は、その日付を含む月または年が開きます。それ以外の場合は、1か月または1年で開き、今日の日付を提供します。

この動作は、 <mat-datepicker>のstartAt プロパティを使用して簡単にオーバーライドできます。この場合、カレンダーは startAt 日付を含む月または年に開きます。

<mat-form-field>
  <input matInput [matDatepicker]="picker" placeholder="Choose a date">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker startView="year" [startAt]="startDate"></mat-datepicker>
</mat-form-field>

コードはGithubにあります。

GITHUBコード

AngularDatepickerの検証

3つのプロパティにより、日付検証がdatepicker入力に追加されます。

最初の2つは、最小プロパティと最大プロパティです。

また、入力の検証を強制するために、これらのプロパティは、それぞれの値の前後のカレンダーポップアップのすべての日付を無効にし、ユーザーが最小または最大の日付を含む月または年（現在のビューに応じて）を超えてカレンダーを進めるのを防ぎます。

次のHTMLマークアップを参照してください。

<mat-form-field class="example-full-width">
  <input matInput [min]="minDate" [max]="maxDate" [matDatepicker]="picker" placeholder="Choose a date">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker></mat-datepicker>
</mat-form-field>

 また、上記のマークアップに関連するtypescriptファイルも参照してください。

import {Component} from '@angular/core';

/** @title Datepicker with min & max validation */
@Component({
  selector: 'datepicker-min-max-example',
  templateUrl: 'datepicker-min-max-example.html',
  styleUrls: ['datepicker-min-max-example.css'],
})
export class DatepickerMinMaxExample {
  minDate = new Date(2000, 0, 1);
  maxDate = new Date(2020, 0, 1);
}

日付検証を追加する2番目の方法は、datepicker入力のmatDatepickerFilterプロパティを使用することです。

このプロパティは、<D> =>ブール値の関数を受け入れます（<D>は、datepickerで使用される日付型です。日付の実装の選択を参照してください）。

真の結果は日付が有効であることを示し、偽の結果は日付が有効でないことを示します。

繰り返しますが、これにより、無効なカレンダーの日付も無効になります。

ただし、matDatepickerFilterを使用する場合とminまたはmaxを使用する場合の重要な違いは、特定のポイントの前後のすべての日付を除外しても、ユーザーがそのポイントを超えてカレンダーを進めることを妨げないことです。

次のコード例を参照してください。最初にHTMLマークアップを参照してください。

<mat-form-field class="example-full-width">
  <input matInput [matDatepickerFilter]="myFilter" [matDatepicker]="picker" placeholder="Choose a date">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker></mat-datepicker>
</mat-form-field>

 ここで、上記のマークアップに関連するTypescriptファイルを参照してください。

import {Component} from '@angular/core';

/** @title Datepicker with filter validation */
@Component({
  selector: 'datepicker-filter-example',
  templateUrl: 'datepicker-filter-example.html',
  styleUrls: ['datepicker-filter-example.css'],
})
export class DatepickerFilterExample {
  myFilter = (d: Date): boolean => {
    const day = d.getDay();
    // Prevent Saturday and Sunday from being selected.
    return day !== 0 && day !== 6;
  }
}

この例では、ユーザーは2005年を過ぎて戻ることができますが、それ以前のすべての日付は選択できなくなります。彼らは2000年よりもカレンダーに戻ることはできません。

最小値の前、最大値の後、またはフィルターで除外された日付を手動で入力すると、入力に検証エラーが発生します。

各検証プロパティには、チェックできる異なるエラーがあります。

1. たとえば、minプロパティに違反する値には、matDatepickerMinエラーがあります。
2. maxプロパティに違反する値には、matDatepickerMaxエラーがあります。
3. matDatepickerFilterプロパティに違反する値には、matDatepickerFilterエラーがあります。

角度入力および変更イベント

入力のネイティブ（入力）および（変更）イベントは、入力要素とのユーザーインタラクションのみをトリガーします。ユーザーがカレンダーポップアップから日付を選択しても、これらは起動しません。

したがって、datepicker入力は、（dateInput）および（dateChange）イベントもサポートします。これらは、ユーザーが入力またはポップアップのいずれかを操作したときにトリガーされます。

（dateInput）イベントは、ユーザーがカレンダーから日付を入力または選択したために値が変更されるたびに発生します。同様に、（dateChange）イベントは、ユーザーが入力の入力を終了するたびに（<input>ブラーで）、またはユーザーがカレンダーから日付を選択したときに発生します。

次のHTMLマークアップを参照してください。

<mat-form-field>
  <input matInput [matDatepicker]="picker" placeholder="Input & change events"
         (dateInput)="addEvent('input', $event)" (dateChange)="addEvent('change', $event)">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker></mat-datepicker>
</mat-form-field>

<div class="example-events">
  <div *ngFor="let e of events">{{e}}</div>
</div>

 次に、そのマークアップに関連するtypescriptファイルを参照してください。

import {Component} from '@angular/core';
import {MatDatepickerInputEvent} from '@angular/material/datepicker';

/** @title Datepicker input and change events */
@Component({
  selector: 'datepicker-events-example',
  templateUrl: 'datepicker-events-example.html',
  styleUrls: ['datepicker-events-example.css'],
})
export class DatepickerEventsExample {
  events: string[] = [];

  addEvent(type: string, event: MatDatepickerInputEvent) {
    this.events.push(`${type}: ${event.value}`);
  }
}

AngularDatepickerの一部を無効にする

他の標準の<input>と同様に、disabledプロパティを追加することで、datepicker入力を無効にすることができます。

デフォルトでは、<mat-datepicker>と<mat-datepicker-toggle>は<input>から無効な状態を継承しますが、これは、datepickerまたはtoggle要素にdisabledプロパティを設定することでオーバーライドできます。

これは、テキスト入力を無効にしたいが、カレンダーを介した選択を許可したい場合、またはその逆の場合に非常に便利です。

次のHTMLマークアップを参照してください。

<p>
  <mat-form-field>
    <input matInput [matDatepicker]="dp1" placeholder="Completely disabled" disabled>
    <mat-datepicker-toggle matSuffix [for]="dp1"></mat-datepicker-toggle>
    <mat-datepicker #dp1></mat-datepicker>
  </mat-form-field>
</p>

<p>
  <mat-form-field>
    <input matInput [matDatepicker]="dp2" placeholder="Popup disabled">
    <mat-datepicker-toggle matSuffix [for]="dp2" disabled></mat-datepicker-toggle>
    <mat-datepicker #dp2></mat-datepicker>
  </mat-form-field>
</p>

<p>
  <mat-form-field>
    <input matInput [matDatepicker]="dp3" placeholder="Input disabled" disabled>
    <mat-datepicker-toggle matSuffix [for]="dp3"></mat-datepicker-toggle>
    <mat-datepicker #dp3 disabled="false"></mat-datepicker>
  </mat-form-field>
</p>

 ここで、typescriptファイルを参照してください。

import {Component} from '@angular/core';

/** @title Disabled datepicker */
@Component({
  selector: 'datepicker-disabled-example',
  templateUrl: 'datepicker-disabled-example.html',
  styleUrls: ['datepicker-disabled-example.css'],
})
export class DatepickerDisabledExample {}

このチュートリアルは以上です。 

ソース：https ：//appdividend.com/2022/02/16/angular-datepicker/

#angular 

How To Use Datepicker In Angular for Beginners

Angular Datepicker is a built-in material component that allows us to enter the date through text input or by choosing the date from a calendar. Angular Material Datepicker allows users to enter the date through text input or by choosing the date from the calendar. The Material Datepicker comprises several components and directives that work together.

It is made up of various angular components and directives that work together. First, we need to install Angular. We are using Angular CLI to install the Angular.

1: Install the Angular CLI.

Type the following command.

npm install -g @angular/cli

Now, create the Angular project using the following command.

ng new datepicker

2: Install other libraries.

Go into the project and install the hammerjs using the following command.

npm install --save hammerjs

Hammer.js is the optional dependency and helps with touch support for a few components.

Now, install Angular Material and Angular Animations using the following command.

npm install --save @angular/material @angular/animations @angular/cdk

Now, include hammerjs inside the angular.json file. You can find this file at the root of the project.

3: Import a pre-built theme and Material icons.

Angular Material comes with some pre-built themes. These themes have set off the colors and basic styling.

The main available themes are indigo-pink, deeppurple-amber, purple-green, and pink-bluegrey.

To import the theme, you can add the following code to your global styles.css file. The file is inside the src folder.

@import '~@angular/material/prebuilt-themes/indigo-pink.css';

You can also access the Material Design icons and use named icons with a <mat-icon> component.

If we want to import them to your project, we can add this to the head section of your project’s root index.html file.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>Datepicker</title>
  <base href="/">

  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="icon" type="image/x-icon" href="favicon.ico">
  <link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
</head>
<body>
  <app-root></app-root>
</body>
</html>

4: Create a Custom Material Module File.

Inside the src,>> app folder, create one file called material.module.ts and add the following code.

// material.module.ts

import { NgModule } from '@angular/core';
import { MatDatepickerModule } from '@angular/material';

@NgModule({
  imports: [
    MatDatepickerModule
  ],
  exports: [
    MatDatepickerModule
  ]
})

export class MaterialModule {}

We have imported MatDatepickerModule, MatNativeDateModule, and other components that we need in our Angular Datepicker Example App.

We can add additional components in the future if we need to.

This file is written on its own because it is easy to include all the Material components in this file, and then this file will be imported inside the app.module.ts.

// material.module.ts

import { NgModule } from '@angular/core';
import { MatDatepickerModule,
        MatNativeDateModule,
        MatFormFieldModule,
        MatInputModule } from '@angular/material';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';

@NgModule({
  imports: [
    MatDatepickerModule,
    MatFormFieldModule,
    MatNativeDateModule,
    MatInputModule,
    BrowserAnimationsModule
  ],
  exports: [
    MatDatepickerModule,
    MatFormFieldModule,
    MatNativeDateModule,
    MatInputModule,
    BrowserAnimationsModule
  ],
  providers: [ MatDatepickerModule ],
})

export class MaterialModule {}

5: Import MaterialModule in an app.module.ts file.

Import MaterialModule inside the app.module.ts file.

// app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { MaterialModule } from './material.module';

import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    MaterialModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Also, finally, write the Datepicker HTML code inside the app.component.html file.

<!-- app.component.html -->

<mat-form-field>
  <input matInput [matDatepicker]="picker" placeholder="Choose a date">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker></mat-datepicker>
</mat-form-field>

Save the file, go to a terminal or cmd, and start Angular Development Server.

ng serve --open

Go to the browser, and see something like the below image.

6: Connecting a datepicker to an input

A datepicker comprises text input and a calendar popup, connected via the matDatePicker property on the text input.

<input [matDatepicker]="myDatepicker">
<mat-datepicker #myDatepicker></mat-datepicker>

There is an optional datepicker toggle button available. The toggle button can be added to the example above:

<input [matDatepicker]="myDatepicker">
<mat-datepicker-toggle [for]="myDatepicker"></mat-datepicker-toggle>
<mat-datepicker #myDatepicker></mat-datepicker>

It works the same with an input that is part of a <mat-form-field> and a toggle button can easily be used as a prefix or suffix on the material input:

<mat-form-field>
  <input matInput [matDatepicker]="myDatepicker">
  <mat-datepicker-toggle matSuffix [for]="myDatepicker"></mat-datepicker-toggle>
  <mat-datepicker #myDatepicker></mat-datepicker>
</mat-form-field>

7: Setting the calendar starting view

The startView property of <mat-datepicker> could be used to set the look that will show up when the calendar first opens. It can be configured to month, year, or multi-year; by default, it will begin to month view.

A month, year, or range of years that a calendar opens to is determined by first checking if any date is currently selected, and if so, it will open to a month or year containing that date. Otherwise, it will open in a month or year, providing today’s date.

This behavior can be easily overridden using the startAt property of <mat-datepicker>. In this case, a calendar will open to the month or year containing the startAt date.

<mat-form-field>
  <input matInput [matDatepicker]="picker" placeholder="Choose a date">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker startView="year" [startAt]="startDate"></mat-datepicker>
</mat-form-field>

You can find the code on Github.

Angular Datepicker Validation

Three properties add the date validation to the datepicker input.

The first two are the min and max properties.

Also, to enforce validation on input, these properties will disable all the dates on the calendar popup before or after the respective values and prevent the user from advancing the calendar past the month or year (depending on current view) containing the min or max date.

See the following HTML markup.

<mat-form-field class="example-full-width">
  <input matInput [min]="minDate" [max]="maxDate" [matDatepicker]="picker" placeholder="Choose a date">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker></mat-datepicker>
</mat-form-field>

 Also, see the typescript file related to the above markup.

import {Component} from '@angular/core';

/** @title Datepicker with min & max validation */
@Component({
  selector: 'datepicker-min-max-example',
  templateUrl: 'datepicker-min-max-example.html',
  styleUrls: ['datepicker-min-max-example.css'],
})
export class DatepickerMinMaxExample {
  minDate = new Date(2000, 0, 1);
  maxDate = new Date(2020, 0, 1);
}

The second way to add the date validation is by using the matDatepickerFilter property of the datepicker input.

This property accepts a function of <D> => boolean (where <D> is the date type used by the datepicker, see Choosing a date implementation).

A true result indicates that the date is valid, and a false result suggests that it is not.

Again this will also disable the dates on a calendar that are invalid.

However, a critical difference between using matDatepickerFilter vs. using min or max is that filtering out all dates before or after a certain point will not prevent a user from advancing a calendar past that point.

See the following code example. See first the HTML markup.

<mat-form-field class="example-full-width">
  <input matInput [matDatepickerFilter]="myFilter" [matDatepicker]="picker" placeholder="Choose a date">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker></mat-datepicker>
</mat-form-field>

 Now, see the Typescript file related to the above markup.

import {Component} from '@angular/core';

/** @title Datepicker with filter validation */
@Component({
  selector: 'datepicker-filter-example',
  templateUrl: 'datepicker-filter-example.html',
  styleUrls: ['datepicker-filter-example.css'],
})
export class DatepickerFilterExample {
  myFilter = (d: Date): boolean => {
    const day = d.getDay();
    // Prevent Saturday and Sunday from being selected.
    return day !== 0 && day !== 6;
  }
}

In this example, the user can go back past 2005, but all of the dates before then will be unselectable. They will not be able to go further back in the calendar than 2000.

If they manually type in a date before the min, after the max, or filtered out, the input will have validation errors.

Each validation property has a different error that can be checked:

1. For example, the value that violates a min property will have the matDatepickerMin error.
2. The value that violates a max property will have the matDatepickerMax error.
3. The value that violates a matDatepickerFilter property will have the matDatepickerFilter error.

Angular Input and change events

The input’s native (input) and (change) events will only trigger user interaction with the input element; they will not fire when the user selects the date from the calendar popup.

Therefore, a datepicker input also has support for (dateInput) and (dateChange) events — these triggers when a user interacts with either an input or the popup.

The (dateInput) event will fire whenever the value changes due to the user typing or selecting a date from the calendar. Likewise, the (dateChange) event will fire whenever the user finishes typing input (on <input> blur) or when a user chooses the date from a calendar.

See the following HTML Markup.

<mat-form-field>
  <input matInput [matDatepicker]="picker" placeholder="Input & change events"
         (dateInput)="addEvent('input', $event)" (dateChange)="addEvent('change', $event)">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker></mat-datepicker>
</mat-form-field>

<div class="example-events">
  <div *ngFor="let e of events">{{e}}</div>
</div>

 Now, see the typescript file related to that markup.

import {Component} from '@angular/core';
import {MatDatepickerInputEvent} from '@angular/material/datepicker';

/** @title Datepicker input and change events */
@Component({
  selector: 'datepicker-events-example',
  templateUrl: 'datepicker-events-example.html',
  styleUrls: ['datepicker-events-example.css'],
})
export class DatepickerEventsExample {
  events: string[] = [];

  addEvent(type: string, event: MatDatepickerInputEvent) {
    this.events.push(`${type}: ${event.value}`);
  }
}

Disabling parts of the Angular Datepicker

As with any standard <input>, it is possible to disable the datepicker input by adding the disabled property.

By default, the <mat-datepicker> and <mat-datepicker-toggle> will inherit their disabled state from the <input>, but this can be overridden by setting a disabled property on the datepicker or toggle elements.

This is very useful if you want to disable the text input but allow selection via the calendar or vice-versa.

See the following HTML Markup.

<p>
  <mat-form-field>
    <input matInput [matDatepicker]="dp1" placeholder="Completely disabled" disabled>
    <mat-datepicker-toggle matSuffix [for]="dp1"></mat-datepicker-toggle>
    <mat-datepicker #dp1></mat-datepicker>
  </mat-form-field>
</p>

<p>
  <mat-form-field>
    <input matInput [matDatepicker]="dp2" placeholder="Popup disabled">
    <mat-datepicker-toggle matSuffix [for]="dp2" disabled></mat-datepicker-toggle>
    <mat-datepicker #dp2></mat-datepicker>
  </mat-form-field>
</p>

<p>
  <mat-form-field>
    <input matInput [matDatepicker]="dp3" placeholder="Input disabled" disabled>
    <mat-datepicker-toggle matSuffix [for]="dp3"></mat-datepicker-toggle>
    <mat-datepicker #dp3 disabled="false"></mat-datepicker>
  </mat-form-field>
</p>

 Now, see the typescript file.

import {Component} from '@angular/core';

/** @title Disabled datepicker */
@Component({
  selector: 'datepicker-disabled-example',
  templateUrl: 'datepicker-disabled-example.html',
  styleUrls: ['datepicker-disabled-example.css'],
})
export class DatepickerDisabledExample {}

That’s it for this tutorial.

Angular Datepicker: Cómo Usar Datepicker En Angular 13

Angular Material  está funcionando desde cero con componentes de interfaz de usuario significativos y modernos que funcionan en la web , dispositivos móviles y computadoras de escritorio . 

Los componentes de Angular Material nos ayudarán a construir una interfaz de usuario y una experiencia de usuario atractivas , páginas web y aplicaciones web consistentes y funcionales, manteniendo los principios de diseño web modernos, como la portabilidad y compatibilidad del navegador, la independencia del dispositivo y la degradación elegante.

Selector de fecha angular

Angular Datepicker es un componente de material incorporado que nos permite ingresar la fecha a través de la entrada de texto o eligiendo la fecha de un calendario. Angular Material Datepicker permite a los usuarios ingresar la fecha a través de la entrada de texto o eligiendo la fecha del calendario. Material Datepicker consta de varios componentes y directivas que funcionan juntos.

Se compone de varios componentes angulares y directivas que funcionan en conjunto. Primero, necesitamos instalar Angular. Estamos usando  Angular CLI para instalar  Angular.

Paso 1: Instale la CLI angular.

Escriba el siguiente comando.

npm install -g @angular/cli

Ahora, crea el proyecto Angular usando el siguiente comando.

 

ng new datepicker

Paso 2: Instale otras bibliotecas.

Ingrese al proyecto e instale  hammerjs  usando el siguiente comando.

npm install --save hammerjs

Hammer.js es la dependencia opcional y ayuda con la compatibilidad táctil para algunos componentes.

Ahora, instale  Angular Material  y  Angular Animations  usando el siguiente comando.

npm install --save @angular/material @angular/animations @angular/cdk

Ahora, incluya  hammerjs  dentro del  archivo angular.json  . Puede encontrar este archivo en la raíz del proyecto.

Paso 3: importa un tema preconstruido e íconos de materiales.

Angular Material viene con algunos temas prediseñados. Estos temas han resaltado los colores y el estilo básico.

Los principales temas disponibles son  rosa índigo ,  ámbar morado oscuro ,  verde púrpura  y  gris azulado rosa .

Para importar el tema, puede agregar el siguiente código a su archivo global  styles.css  . El archivo está dentro de la carpeta src  .

@import '~@angular/material/prebuilt-themes/indigo-pink.css';

También puede acceder a los íconos de Material Design  y usar íconos con nombre con un   componente <mat-icon> .

Si queremos importarlos a su proyecto, podemos agregar esto a la sección principal del   archivo raíz index.html de su proyecto.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>Datepicker</title>
  <base href="/">

  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="icon" type="image/x-icon" href="favicon.ico">
  <link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
</head>
<body>
  <app-root></app-root>
</body>
</html>

Paso 4: cree un archivo de módulo de material personalizado.

Dentro de la carpeta src,>> app  , cree un archivo llamado  material.module.ts  y agregue el siguiente código.

// material.module.ts

import { NgModule } from '@angular/core';
import { MatDatepickerModule } from '@angular/material';

@NgModule({
  imports: [
    MatDatepickerModule
  ],
  exports: [
    MatDatepickerModule
  ]
})

export class MaterialModule {}

Hemos importado MatDatepickerModule, MatNativeDateModule  y otros componentes que necesitamos en nuestra  aplicación de ejemplo Angular Datepicker  .

Podemos agregar componentes adicionales en el futuro si es necesario.

Este archivo se escribe solo porque es fácil incluir todos los componentes de Material en este archivo, y luego este archivo se importará dentro de  app.module.ts.

// material.module.ts

import { NgModule } from '@angular/core';
import { MatDatepickerModule,
        MatNativeDateModule,
        MatFormFieldModule,
        MatInputModule } from '@angular/material';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';

@NgModule({
  imports: [
    MatDatepickerModule,
    MatFormFieldModule,
    MatNativeDateModule,
    MatInputModule,
    BrowserAnimationsModule
  ],
  exports: [
    MatDatepickerModule,
    MatFormFieldModule,
    MatNativeDateModule,
    MatInputModule,
    BrowserAnimationsModule
  ],
  providers: [ MatDatepickerModule ],
})

export class MaterialModule {}

Paso 5: importe MaterialModule en un archivo app.module.ts.

Importe MaterialModule dentro del archivo app.module.ts  .

// app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { MaterialModule } from './material.module';

import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    MaterialModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Además, finalmente, escriba el código HTML de Datepicker dentro del archivo app.component.html  .

<!-- app.component.html -->

<mat-form-field>
  <input matInput [matDatepicker]="picker" placeholder="Choose a date">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker></mat-datepicker>
</mat-form-field>

Guarde el archivo, vaya a una terminal o cmd e inicie Angular Development Server.

ng serve --open

Vaya al navegador y vea algo como la imagen de abajo.

Paso 6: Conectar un selector de fechas a una entrada

Un selector de fecha consta de entrada de texto y una ventana emergente de calendario, conectados a través de la propiedad matDatePicker  en la entrada de texto.

<input [matDatepicker]="myDatepicker">
<mat-datepicker #myDatepicker></mat-datepicker>

Hay un botón de alternar selector de fecha opcional disponible. El botón de alternar se puede agregar al ejemplo anterior:

<input [matDatepicker]="myDatepicker">
<mat-datepicker-toggle [for]="myDatepicker"></mat-datepicker-toggle>
<mat-datepicker #myDatepicker></mat-datepicker>

Funciona de la misma manera con una entrada que es parte de un <mat-form-field> y un botón de alternar se puede usar fácilmente como prefijo o sufijo en la entrada de material:

<mat-form-field>
  <input matInput [matDatepicker]="myDatepicker">
  <mat-datepicker-toggle matSuffix [for]="myDatepicker"></mat-datepicker-toggle>
  <mat-datepicker #myDatepicker></mat-datepicker>
</mat-form-field>

Paso 7: Configuración de la vista de inicio del calendario

La  propiedad startView  de <mat-datepicker> podría usarse para establecer el aspecto que se mostrará cuando se abra el calendario por primera vez. Puede configurarse para  mes ,  año o  varios años ; de forma predeterminada, comenzará a ver el mes.

Un mes, año o rango de años en los que se abre un calendario se determina comprobando primero si alguna fecha está actualmente seleccionada y, de ser así, se abrirá en un mes o año que contenga esa fecha. De lo contrario, se abrirá en un mes o año, proporcionando la fecha de hoy.

Este comportamiento se puede anular fácilmente usando la  propiedad startAt de <mat-datepicker> . En este caso, se abrirá un calendario en el mes o año que contiene la  fecha startAt  .

<mat-form-field>
  <input matInput [matDatepicker]="picker" placeholder="Choose a date">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker startView="year" [startAt]="startDate"></mat-datepicker>
</mat-form-field>

Puedes encontrar el código en Github.

CÓDIGO GITHUB

Validación de selector de fecha angular

Tres propiedades agregan la validación de fecha a la entrada del selector de fecha.

Los dos primeros son las propiedades min y max .

Además, para hacer cumplir la validación en la entrada, estas propiedades deshabilitarán todas las fechas en la ventana emergente del calendario antes o después de los valores respectivos y evitarán que el usuario avance el calendario más allá del mes o año (según la vista actual) que contiene la fecha mínima o máxima. .

Consulte el siguiente marcado HTML.

<mat-form-field class="example-full-width">
  <input matInput [min]="minDate" [max]="maxDate" [matDatepicker]="picker" placeholder="Choose a date">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker></mat-datepicker>
</mat-form-field>

 Además, consulte el archivo mecanografiado relacionado con el marcado anterior.

import {Component} from '@angular/core';

/** @title Datepicker with min & max validation */
@Component({
  selector: 'datepicker-min-max-example',
  templateUrl: 'datepicker-min-max-example.html',
  styleUrls: ['datepicker-min-max-example.css'],
})
export class DatepickerMinMaxExample {
  minDate = new Date(2000, 0, 1);
  maxDate = new Date(2020, 0, 1);
}

La segunda forma de agregar la validación de fecha es usando la propiedad matDatepickerFilter de la entrada del selector de fecha.

Esta propiedad acepta una función de <D> => booleano (donde <D> es el tipo de fecha utilizado por el selector de fecha, consulte Elección de una implementación de fecha).

Un resultado verdadero indica que la fecha es válida y un resultado falso sugiere que no lo es.

Nuevamente, esto también deshabilitará las fechas en un calendario que no son válidas.

Sin embargo, una diferencia crítica entre usar matDatepickerFilter y usar min o max es que filtrar todas las fechas antes o después de cierto punto no evitará que un usuario avance un calendario más allá de ese punto.

Consulte el siguiente ejemplo de código. Vea primero el marcado HTML.

<mat-form-field class="example-full-width">
  <input matInput [matDatepickerFilter]="myFilter" [matDatepicker]="picker" placeholder="Choose a date">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker></mat-datepicker>
</mat-form-field>

 Ahora, vea el archivo TypeScript relacionado con el marcado anterior.

import {Component} from '@angular/core';

/** @title Datepicker with filter validation */
@Component({
  selector: 'datepicker-filter-example',
  templateUrl: 'datepicker-filter-example.html',
  styleUrls: ['datepicker-filter-example.css'],
})
export class DatepickerFilterExample {
  myFilter = (d: Date): boolean => {
    const day = d.getDay();
    // Prevent Saturday and Sunday from being selected.
    return day !== 0 && day !== 6;
  }
}

En este ejemplo, el usuario puede retroceder hasta 2005, pero todas las fechas anteriores no podrán seleccionarse. No podrán retroceder más en el calendario que 2000.

Si escriben manualmente una fecha antes del mínimo, después del máximo o filtrada, la entrada tendrá errores de validación.

Cada propiedad de validación tiene un error diferente que se puede verificar:

1. Por ejemplo, el valor que viola una propiedad mínima tendrá el error matDatepickerMin.
2. El valor que viola una propiedad máxima tendrá el error matDatepickerMax.
3. El valor que viola una propiedad matDatepickerFilter tendrá el error matDatepickerFilter.

Entrada angular y eventos de cambio

Los eventos nativos (entrada) y (cambio) de la entrada solo activarán la interacción del usuario con el elemento de entrada; no se activarán cuando el usuario seleccione la fecha de la ventana emergente del calendario.

Por lo tanto, una entrada de selector de fecha también admite eventos (dateInput) y (dateChange), que se activan cuando un usuario interactúa con una entrada o la ventana emergente.

El evento (dateInput) se activará siempre que el valor cambie debido a que el usuario escribe o selecciona una fecha del calendario. Del mismo modo, el evento (dateChange) se activará cada vez que el usuario termine de escribir la entrada (en <input> blur) o cuando un usuario elija la fecha de un calendario.

Consulte el siguiente marcado HTML.

<mat-form-field>
  <input matInput [matDatepicker]="picker" placeholder="Input & change events"
         (dateInput)="addEvent('input', $event)" (dateChange)="addEvent('change', $event)">
  <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle>
  <mat-datepicker #picker></mat-datepicker>
</mat-form-field>

<div class="example-events">
  <div *ngFor="let e of events">{{e}}</div>
</div>

 Ahora, vea el archivo mecanografiado relacionado con ese marcado.

import {Component} from '@angular/core';
import {MatDatepickerInputEvent} from '@angular/material/datepicker';

/** @title Datepicker input and change events */
@Component({
  selector: 'datepicker-events-example',
  templateUrl: 'datepicker-events-example.html',
  styleUrls: ['datepicker-events-example.css'],
})
export class DatepickerEventsExample {
  events: string[] = [];

  addEvent(type: string, event: MatDatepickerInputEvent) {
    this.events.push(`${type}: ${event.value}`);
  }
}

Deshabilitar partes de Angular Datepicker

Al igual que con cualquier <entrada> estándar, es posible deshabilitar la entrada del selector de fecha agregando la propiedad deshabilitada.

De forma predeterminada, <mat-datepicker> y <mat-datepicker-toggle> heredarán su estado deshabilitado de <input>, pero esto se puede anular configurando una propiedad deshabilitada en el selector de fecha o los elementos de alternancia.

Esto es muy útil si desea deshabilitar la entrada de texto pero permitir la selección a través del calendario o viceversa.

Consulte el siguiente marcado HTML.

<p>
  <mat-form-field>
    <input matInput [matDatepicker]="dp1" placeholder="Completely disabled" disabled>
    <mat-datepicker-toggle matSuffix [for]="dp1"></mat-datepicker-toggle>
    <mat-datepicker #dp1></mat-datepicker>
  </mat-form-field>
</p>

<p>
  <mat-form-field>
    <input matInput [matDatepicker]="dp2" placeholder="Popup disabled">
    <mat-datepicker-toggle matSuffix [for]="dp2" disabled></mat-datepicker-toggle>
    <mat-datepicker #dp2></mat-datepicker>
  </mat-form-field>
</p>

<p>
  <mat-form-field>
    <input matInput [matDatepicker]="dp3" placeholder="Input disabled" disabled>
    <mat-datepicker-toggle matSuffix [for]="dp3"></mat-datepicker-toggle>
    <mat-datepicker #dp3 disabled="false"></mat-datepicker>
  </mat-form-field>
</p>

 Ahora, vea el archivo mecanografiado.

import {Component} from '@angular/core';

/** @title Disabled datepicker */
@Component({
  selector: 'datepicker-disabled-example',
  templateUrl: 'datepicker-disabled-example.html',
  styleUrls: ['datepicker-disabled-example.css'],
})
export class DatepickerDisabledExample {}

Eso es todo por este tutorial. 

Fuente: https://appdividend.com/2022/02/16/angular-datepicker/

#angular