Rodney Vg

Rodney Vg

1592036100

A Vue.js plugin to control an HTML5 canvas using EaselJS

vue-easeljs

A Vue.js plugin to control an HTML5 canvas using EaselJS

Thanks

Thanks go to:

Getting Started

Install vue-easeljs

On the command line:

npm install vue-easeljs --save

In app.js:

Vue.use(require('vue-easeljs'));

In your Vue.js code start with an easel-canvas component. Other components reside within it.

The earliest components are hidden by later components whenever they overlap.

Example

See Live Demo

Components

easel-bitmap

Show a static image.

Attributes:

Attribute Values Description Required/Default
align alignment controls what point of the image the x and y refer to. Default: ‘top-left’
alpha 0 to 1 controls the opacity of the image. Default: 1, completely opaque
cache boolean instead of drawing from source constantly, use a cached version of the source Default: false
cursor string set the CSS mouse cursor to use when hovering over this bitmap Default: null
filters filters apply filters. Default: null
flip ‘horizontal’ ‘vertical’ ‘both’
image string relative or absolute URL to an image file. Required
rotation degrees rotates the image. Default: 0
scale number resizes the image. Default: 1
shadow shadow cast an image-shaped shadow. Default: null
visible boolean draw or do not draw the bitmap on canvas Default: true
x number horizontal position based on the origin of the parent component. Default: 0
y number vertical position based on the origin of the parent component. Default: 0

Example:

<easel-bitmap
    image="/images/awesome-background.jpg"
    :x="0"
    :y="0"
    :align="['left','top']"
>
</easel-bitmap>

See Live Demo

easel-canvas

Give the vue-easeljs components a place to live. The canvas has no visible pixels of its own.

Attributes:

Attribute Values Description Required/Default
anti-alias boolean whether or not edges should be smoothed on scaled images. Default: true
height number the pixel height of the canvas on the page. Default: 300
width number the pixel width of the canvas on the page. Default: 150
viewport-height number the pixel height of the canvas internally. Default: equal to height
viewport-width number the pixel width of the canvas internally. Default: equal to width

The width and height props control the size of the canvas element on the page.

The separate viewport-width and viewport-height props control the size of the canvas internally. For example, a canvas with width and height of 100 can fully show an element of width and height 50. But the same canvas with viewport-width and viewport-height set to 40 cannot fully show the same element.

The viewport-width and viewport-height props are a convenience feature, allowing a developer to specify subcomponents’ pixel sizes at a set size regardless of the actual size of the canvas. Setting small viewport sizes will make elements inside appear larger and pixelated, but if those elements are then scaled down they will not be pixelated. They will regain their original size and pixelation.

Example:

<easel-canvas width="500" height="100">
    <easel-shape
        form="rect"
        :dimensions="[500,100]"
        :x="0"
        :y="0"
        fill="#CCCCFF"
    >
    </easel-shape>
    <easel-text
        text="This is so easy!"
        :x="250"
        :y="75"
        font="70px Calibri"
        color="white"
        :shadow="['#000088',3,2,3]"
        :align="['center', 'alphabetical']"
    >
    </easel-text>
</easel-canvas>

See Live Demo

easel-container

Group other vue-easel components together and manipulate them as one. The container has no visible pixels of its own.

Attributes:

Attribute Values Description Required/Default
alpha 0 to 1 controls the opacity of the container’s contents. Default: 1, completely opaque
cache boolean instead of drawing contained element from source constantly, use a cached version of all elements together Default: false
cursor string set the CSS mouse cursor to use when hovering over the elements in this container Default: null
filters filters apply filters. Default: null
flip ‘horizontal’ ‘vertical’ ‘both’
rotation degrees rotates the container. Default: 0
scale number resizes the container. Default: 1
shadow shadow cast a shadow of all contained components. Default: null
visible boolean draw or do not draw the container’s elements on canvas Default: true
x number horizontal position based on the origin of the parent component. Default: 0
y number vertical position based on the origin of the parent component. Default: 0

Example:

<easel-container
    flip="horizontal"
    scale=".5"
    :x="250"
    :y="50"
>
    <easel-bitmap
        image="/images/wooden-sign-texture.png"
    >
    </easel-bitmap>
    <easel-text
        text="Dan's Left Shoe Emporium"
        font="50px 'Times New Roman'"
        :y="25"
    >
    </easel-text>
</easel-container>

See Live Demo

easel-shape

Show a shape.

Attributes:

Attribute Values Description Required/Default
align alignment controls what point of the shape the x and y refer to. Default: ‘top-left’
alpha 0 to 1 controls the opacity of the shape. Default: 1, completely opaque
cache boolean instead of drawing the shape constantly, use a cached version of the shape Default: false
cursor string set the CSS mouse cursor to use when hovering over this shape Default: null
dimensions Depends on the form. See below. Required
fill HTML color the inside of the shape Optional.
filters filters apply filters. Default: null
flip ‘horizontal’ ‘vertical’ ‘both’
form ‘circle’ ‘ellipse’ ‘rect’
rotation degrees rotates the shape. Default: 0
scale number resizes the shape. Default: 1
shadow shadow cast a same-shape shadow. Default: null
stroke HTML color the outline of the shape. Optional.
visible boolean draw or do not draw the shape on canvas Default: true
x number horizontal position based on the origin of the parent component. Default: 0
y number vertical position based on the origin of the parent component. Default: 0

Dimensions for:

Shape Dimension Type Format Value explanation
circle number the radius of the circle.
ellipse array [w, h] the width and height of the ellipse.
rect array [w, h], or [w, h, r], or [w, h, topLeft, topRight, bottomRight, bottomLeft] the width and height of the rectangle. Optionally include the radius of rounded corners as one value or four.
star array [r, s, p] the radius, sides count, and point size of a “star”. Use point size 0 to draw a simple polygon. Max point size is 1.

Example:

<easel-shape
    form="star"
    :dimensions="[100, 3, 0]"
    fill="blue"
    stroke="red"
    :x="100"
    :y="100"
>

See Live Demo

easel-sprite

Show a moving image. An easel-sprite must reside in an easel-sprite-sheet node. The easel-sprite-sheet defines the animations that can be used by the easel-sprite.

Attributes:

Attribute Values Description Required/Default
align alignment controls what point of the image the x and y refer to. Default: ‘top-left’
alpha 0 to 1 controls the opacity of the image. Default: 1, completely opaque
animation string name of the animation to run from the easel-sprite-sheet. Required
cache boolean instead of drawing from source constantly, use a cached version of the source Default: false
cursor string set the CSS mouse cursor to use when hovering over this sprite Default: null
filters filters apply filters. Default: null
flip ‘horizontal’ ‘vertical’ ‘both’
rotation degrees rotates the image. Default: 0
scale number resizes the image. Default: 1
shadow shadow cast an image-shaped shadow. Default: null
visible boolean draw or do not draw the sprite on canvas Default: true
x number horizontal position based on the origin of the parent component. Default: 0
y number vertical position based on the origin of the parent component. Default: 0

Example:

See the easel-sprite-sheet example below.

easel-sprite-sheet

Define image animations for use in a sprite.

Attributes:

Attribute Values Description Required/Default
animations object defines names for animations. Each animation is a series of frames. Required
framerate number the speed the animation should play at. Required
frames mixed usually an object with format: {width: width, height: height}. Required
images array relative or absolute URL’s to image files. Required

EaselJS provides a lot of options for defining sprite sheets, to allow you to format the images in whatever way suits you.

A sprite sheet is a single image with a set of images on it that will be used in rotation to show an animation.

The friendliest approach is to layout the images in a grid. For example, if a character requires 32x32 pixels to show, you might create a sprite sheet with 10 frames of the character in a 320x32 pixel image. Or a 32x320 image. Or a 160x64 image. Whatever the image size, EaselJS will figure it out based on the width and height you give it.

In that case the following definition will do nicely:

<easel-sprite-sheet
    :images="['/images/character.png']"
    :frames="{width: 32, height: 32}"
    ...
>

But sometimes frames have space between them or margins around them. In these cases, you’ll need to specify more information.

In this example, there is space and margin between the frames.

<easel-sprite-sheet
    :images="['/images/lots-of-characters.png']"
    :frames="{width: 32, height: 32, spacing: 5, margin: 10}"
    ...
>

Other times, the frames are different sizes or are on different images.

In that case, this format will be required:

<easel-sprite-sheet
    :images="['/images/thomasChugging.png','/images/thomasBraking.png']"
    :frames="[
        // x, y, width, height, imageIndex
        [0, 0, 64, 32, 0],
        [0, 32, 64, 32, 0],
        ...
    ]"
    ...
>

Animations give names to a series of frames. The name is used in the easel-sprite component to determine what to show.

The value of an animation is a number, array, or object.

If the animation is just one frame, a number is appropriate.

If the animation is multiple frames laid out in order in the sprite sheet, then the array short form can be used. The first two values are the start and end of the animation. The third value is an optional next animation to begin when this one is done. The fourth is speed.

If the animation uses frames that are not in order, use an object with the field frames and the optional next and speed.

animations: {
    stand: 0,
    run: [1, 4, "stand"],
    fall: {
        frames: [5, 1, 0, 2],
    },
}

Example:

<easel-sprite-sheet
    :images="['images/lastguardian-all.png']"
    :frames="{width:32,height:32}"
    :animations="{
        stand: 7,
        walk: [6, 7],
        walkAndStand: [6, 7, 'stand'],
        confusion: {
            frames: [5, 1, 0, 2],
        },
    }"
    :framerate="4"
>
    <easel-sprite
        :x="32"
        :y="32"
        animation="walkAndStand"
    >
    </easel-sprite>
>
</easel-sprite-sheet>

See Live Demo

easel-text

Show some text.

Attributes:

Attribute Values Description Required/Default
align alignment controls what point of the text the x and y refer to. Default: ‘top-left’
alpha 0 to 1 controls the opacity of the text. Default: 1, completely opaque
cache boolean instead of drawing constantly, use a cached version of the text Default: false
color HTML color the color to use for the text. Default: ‘black’
cursor string set the CSS mouse cursor to use when hovering over this text Default: null
filters filters apply filters. Default: null
flip ‘horizontal’ ‘vertical’ ‘both’
font font size and family of the font. Format: “Npx family”. Default: ?
rotation degrees rotates the text. Default: 0
scale number resizes the text. Default: 1
shadow shadow cast a text-shaped shadow. Default: null
text string the text to display. Required
visible boolean draw or do not draw the text on canvas Default: true
x number horizontal position based on the origin of the parent component. Default: 0
y number vertical position based on the origin of the parent component. Default: 0

Example:

<easel-text
    text="The Ran In Span Falls Manly On The Plan"
    :x="250"
    :y="32"
    font="20px Arial"
    color="red"
>
</easel-text>

See Live Demo

Align attribute

All visible components can accept an align attribute. The align attribute defaults to 'top-left'.

The values refer to where the x, y coordinates should lie in reference to the rest of the object.

For example, if a 50x50 square shape is aligned at ‘top-left’, and its x and y are at 65, 70, then the square’s top left point will be at 65, 70 and its bottom right point will be at 115, 120.

top left alignment

If the same square was aligned at ‘bottom-right’, then it’s bottom right point would be at 65, 70 and its top left point would be at 15, 20.

bottom right alignment

The field can be either a string or an array.

As a string it is formatted as ‘vertical-horizontal’.

As an array it is formatted as [vertical, horizontal].

Most components have these alignment options:

  • vertical: top, center, bottom
  • horizontal: left, center, right

The easel-text component has extra alignment options:

  • vertical: top, hanging, middle, alphabetic, ideographic, bottom
  • horizontal: start, end, left, right, center

These are described in the whatwg spec for HTML5 canvases. In cases of text with multiple lines, the horizontal alignment value applies to every line.

Note: For backwards compatibility, the horizontal and vertical parts of the string or array can be reversed. Future major versions will obsolete this option.

Cache attribute

The cache attribute is a boolean.

When caching is active, a rasterized version of the element is created in memory and used instead of the source material that the element uses. The element essentially becomes an EaselBitmap.

Many of an element’s props will cause a cache refresh when they are changed.

The props alpha, flip, rotation, shadow, x, and y are applied to an element after caching and will not cause a cache refresh. However, if an element is part of a cached EaselContainer, changing those props on the child element will refresh the container’s cache.

An animated sprite will refresh the rasterized image on each frame change.

And so a cached element should behave no differently from a non-cached element in most respects.

The difference is that caching has an impact on performance. In many cases it increases an element’s speed, but if the cache needs to refresh often it can decrease speed.

Caching exists for those performance purposes and also because it will be necessary when filters are implemented in a future version of this library.

Filters attribute

Filters process a visual element’s pixels, applying adjustments after the element is drawn.

The filters attribute is an array of arrays. Each filter array consists of the name of a filter followed by parameters.

Several filters can be applied to the same element.

Supplying filters forces cache to be true.

Available filters

This library comes pre-built with several filters.

BlurFilter

Blur an element. Applies to shadows as well.

['BlurFilter', x, y, quality]

Parameter Range Default
x horizontal bluriness 0 - Infinity 0
y vertical bluriness 0 - Infinity 0
quality the number of blur iterations 0 - Infinity 1

ColorFilter

Systematically change the coloring of an element. Applies before shadowing is done. Use inside a container to include shadow.

['ColorFilter', rX, gX, bX, aX, rO, gO, bO]

Parameter Range Default
rX red multiplier 0 to 1 1
gX green multiplier 0 to 1 1
bX blue multiplier 0 to 1 1
aX alpha multiplier 0 to 1 1
rO red offset -255 to 255 0
gO green offset -255 to 255 0
bO blue offset -255 to 255 0

ColorMatrixFilter

Adjust the brightness, contrast, saturation, and hue of an element.

['ColorMatrixFilter', brightness, contrast, saturation, hue]

Parameter Range Default
brightness add to the brightness -255 - 255 undefined - no change
contrast add to the contrast -100 - 100 undefined - no change
saturation add to the saturation -100 - 100 undefined - no change
hue add to the hue -180 - 180 undefined - no change

PixelStrokeFilter

Add a pixelated stroke around the element.

['PixelStrokeFilter', [r, g, b, a]]

Parameter Range Default
color color of stroke as array of red, green, blue, alpha array, values 0 - 255 [0, 0, 0, 255]

Not yet available

EaselJS has two filters – AlphaMapFilter and AlphaMaskFilter – that are not yet available, because their use requires complicated access to canvases. The idiom of this library is that you should never have to access a canvas. In the future this library should provide an <easel-mask> element to do masking, making those filters unnecessary.

Custom filters

Create new filters by registering a class with the VueEaseljs library at runtime using VueEaseljs.registerFilter.

See further documentation on Custom filters.

Example:

const VueEaseljs = require('vue-easeljs');

class MyFilter {

    constructor(value1, value2) {
        ...
    }

    adjustContext(ctx, x, y, width, height, targetCtx, targetX, targetY) {
        ...
    }
}

VueEaseljs.registerFilter('MyFilter', MyFilter);

Font attribute

The font attribute is a string that controls the family, size, and weight of text in an easel-text component.

The string is mostly compatible with the CSS font property with some changes.

In most cases it must include the font size and font family.

Example: “16px Garamond”

It can optionally include any of font style, font variant, font weight, and font stretch, in that order, before the font size.

Example: “italic small-caps bold 16px cursive”

Shadow attribute

All visible components can drop a shadow with an optional shadow attribute.

The field is formatted as [color, xOffset, yOffset, bluriness].

Shadow options:

  • color: HTML color
  • xOffset: number
  • yOffset: number
  • bluriness: number

Events

All visible components and the canvas itself emit Vue.js events with an event object.

Event Fired when…
added Fired when the component is added to its parent.
animationend (easel-sprite only) Fired when an animation completes.
change (easel-sprite only) Fired when an animation changes.
click Fired when the component is clicked or tapped.
dblclick Fired when the component is double-clicked or tapped.
mousedown Fired when the component is clicked down.
mouseout Fired when the mouse leaves a component’s hit area.
mouseover Fired when the mouse enters a component’s hit area.
pressmove Fired when the component is dragged.
pressup Fired when the component is unclicked.
removed Fired when the component is removed from its parent.
rollout Fired when the mouse leaves a component’s hit area.
rollover Fired when the mouse enters a comopnent’s hit area.
tick Fired many times a second to keep the components in sync. Using this event can impact performance.

Modifiers such as .stop usually work with the events.

For performance reasons, the events are only emitted if a handler exists. They will not show up in the Vue.js devtools if no handler exists.

These events will be made available in a future release:

  • drawend
  • drawstart
  • mouseenter
  • mouseleave
  • stagemousedown
  • stagemousemove
  • stagemouseup
  • tickend
  • tickstart

Developer Tips

Chrome/Chromium Users:

  • When developing locally, Chrome limits canvas access to local image files. They can be viewed but click events will error out unless Chrome is opened with the --allow-file-access-from-files flag. But be careful, since this flag opens your system up to some danger if the scripts you run on your page are untrustworthy. This is a limitation of canvas that applies to all canvas libraries. Fortunately, Chrome has this workaround. Unfortunately, it can stop working and require a browser restart.

All users:

  • When accessing image files from other hosts, CORS must be setup on the foreign host or else click events will error out. This is a limitation of canvas that applies to all canvas libraries.

The EaselJS documents can be helpful. They are essential if you intend to fork this repo and make pull requests.

Pending

These will be implemented in future releases:

  • Percentages
  • Pre-load images
  • Masks
  • Mouse cursors
  • Hit areas
  • Filters

There are no plans to implement these features that EaselJS provides, but pull requests are accepted:

  • BitmapText
  • Buttons
  • Complex Vector Paths
  • MovieClip

Contribution

If you find a bug or want to contribute to the code or documentation, you can help by submitting an issue or a pull request.

Download Details:

Author: dankuck

GitHub: https://github.com/dankuck/vue-easeljs

#vuejs #javascript #vue #vue-js

What is GEEK

Buddha Community

A Vue.js plugin to control an HTML5 canvas using EaselJS
Aria Barnes

Aria Barnes

1625232484

Why is Vue JS the most Preferred Choice for Responsive Web Application Development?

For more than two decades, JavaScript has facilitated businesses to develop responsive web applications for their customers. Used both client and server-side, JavaScript enables you to bring dynamics to pages through expanded functionality and real-time modifications.

Did you know!

According to a web development survey 2020, JavaScript is the most used language for the 8th year, with 67.7% of people choosing it. With this came up several javascript frameworks for frontend, backend development, or even testing.

And one such framework is Vue.Js. It is used to build simple projects and can also be advanced to create sophisticated apps using state-of-the-art tools. Beyond that, some other solid reasons give Vuejs a thumbs up for responsive web application development.

Want to know them? Then follow this blog until the end. Through this article, I will describe all the reasons and benefits of Vue js development. So, stay tuned.

Vue.Js - A Brief Introduction

Released in the year 2014 for public use, Vue.Js is an open-source JavaScript framework used to create UIs and single-page applications. It has over 77.4 million likes on Github for creating intuitive web interfaces.

The recent version is Vue.js 2.6, and is the second most preferred framework according to Stack Overflow Developer Survey 2019.

Every Vue.js development company is widely using the framework across the world for responsive web application development. It is centered around the view layer, provides a lot of functionality for the view layer, and builds single-page web applications.

Some most astonishing stats about Vue.Js:

• Vue was ranked #2 in the Front End JavaScript Framework rankings in the State of JS 2019 survey by developers.

• Approximately 427k to 693k sites are built with Vue js, according to Wappalyzer and BuiltWith statistics of June 2020.

• According to the State of JS 2019 survey, 40.5% of JavaScript developers are currently using Vue, while 34.5% have shown keen interest in using it in the future.

• In Stack Overflow's Developer Survey 2020, Vue was ranked the 3rd most popular front-end JavaScript framework.

Why is Vue.Js so popular?

• High-speed run-time performance
• Vue.Js uses a virtual DOM.
• The main focus is on the core library, while the collaborating libraries handle other features such as global state management and routing.
• Vue.JS provides responsive visual components.

Top 7 Reasons to Choose Vue JS for Web Application Development

Vue js development has certain benefits, which will encourage you to use it in your projects. For example, Vue.js is similar to Angular and React in many aspects, and it continues to enjoy increasing popularity compared to other frameworks.

The framework is only 20 kilobytes in size, making it easy for you to download files instantly. Vue.js easily beats other frameworks when it comes to loading times and usage.

Take a look at the compelling advantages of using Vue.Js for web app development.

#1 Simple Integration

Vue.Js is popular because it allows you to integrate Vue.js into other frameworks such as React, enabling you to customize the project as per your needs and requirements.

It helps you build apps with Vue.js from scratch and introduce Vue.js elements into their existing apps. Due to its ease of integration, Vue.js is becoming a popular choice for web development as it can be used with various existing web applications.

You can feel free to include Vue.js CDN and start using it. Most third-party Vue components and libraries are additionally accessible and supported with the Vue.js CDN.

You don't need to set up node and npm to start using Vue.js. This implies that it helps develop new web applications, just like modifying previous applications.

The diversity of components allows you to create different types of web applications and replace existing frameworks. In addition, you can also choose to hire Vue js developers to use the technology to experiment with many other JavaScript applications.

#2 Easy to Understand

One of the main reasons for the growing popularity of Vue.Js is that the framework is straightforward to understand for individuals. This means that you can easily add Vue.Js to your web projects.

Also, Vue.Js has a well-defined architecture for storing your data with life-cycle and custom methods. Vue.Js also provides additional features such as watchers, directives, and computed properties, making it extremely easy to build modern apps and web applications with ease.

Another significant advantage of using the Vue.Js framework is that it makes it easy to build small and large-scale web applications in the shortest amount of time.

#3 Well-defined Ecosystem

The VueJS ecosystem is vibrant and well-defined, allowing Vue.Js development company to switch users to VueJS over other frameworks for web app development.

Without spending hours, you can easily find solutions to your problems. Furthermore, VueJs lets you choose only the building blocks you need.

Although the main focus of Vue is the view layer, with the help of Vue Router, Vue Test Utils, Vuex, and Vue CLI, you can find solutions and recommendations for frequently occurring problems.

The problems fall into these categories, and hence it becomes easy for programmers to get started with coding right away and not waste time figuring out how to use these tools.

The Vue ecosystem is easy to customize and scales between a library and a framework. Compared to other frameworks, its development speed is excellent, and it can also integrate different projects. This is the reason why most website development companies also prefer the Vue.Js ecosystem over others.

#4 Flexibility

Another benefit of going with Vue.Js for web app development needs is flexibility. Vue.Js provides an excellent level of flexibility. And makes it easier for web app development companies to write their templates in HTML, JavaScript, or pure JavaScript using virtual nodes.

Another significant benefit of using Vue.Js is that it makes it easier for developers to work with tools like templating engines, CSS preprocessors, and type checking tools like TypeScript.

#5 Two-Way Communication

Vue.Js is an excellent option for you because it encourages two-way communication. This has become possible with the MVVM architecture to handle HTML blocks. In this way, Vue.Js is very similar to Angular.Js, making it easier to handle HTML blocks as well.

With Vue.Js, two-way data binding is straightforward. This means that any changes made by the developer to the UI are passed to the data, and the changes made to the data are reflected in the UI.

This is also one reason why Vue.Js is also known as reactive because it can react to changes made to the data. This sets it apart from other libraries such as React.Js, which are designed to support only one-way communication.

#6 Detailed Documentation

One essential thing is well-defined documentation that helps you understand the required mechanism and build your application with ease. It shows all the options offered by the framework and related best practice examples.

Vue has excellent docs, and its API references are one of the best in the industry. They are well written, clear, and accessible in dealing with everything you need to know to build a Vue application.

Besides, the documentation at Vue.js is constantly improved and updated. It also includes a simple introductory guide and an excellent overview of the API. Perhaps, this is one of the most detailed documentation available for this type of language.

#7 Large Community Support

Support for the platform is impressive. In 2018, support continued to impress as every question was answered diligently. Over 6,200 problems were solved with an average resolution time of just six hours.

To support the community, there are frequent release cycles of updated information. Furthermore, the community continues to grow and develop with backend support from developers.



Wrapping Up

VueJS is an incredible choice for responsive web app development. Since it is lightweight and user-friendly, it builds a fast and integrated web application. The capabilities and potential of VueJS for web app development are extensive.

While Vuejs is simple to get started with, using it to build scalable web apps requires professionalism. Hence, you can approach a top Vue js development company in India to develop high-performing web apps.

Equipped with all the above features, it doesn't matter whether you want to build a small concept app or a full-fledged web app; Vue.Js is the most performant you can rely on.

Original source

 

#vue js development company #vue js development company in india #vue js development company india #vue js development services #vue js development #vue js development companies

NBB: Ad-hoc CLJS Scripting on Node.js

Nbb

Not babashka. Node.js babashka!?

Ad-hoc CLJS scripting on Node.js.

Status

Experimental. Please report issues here.

Goals and features

Nbb's main goal is to make it easy to get started with ad hoc CLJS scripting on Node.js.

Additional goals and features are:

  • Fast startup without relying on a custom version of Node.js.
  • Small artifact (current size is around 1.2MB).
  • First class macros.
  • Support building small TUI apps using Reagent.
  • Complement babashka with libraries from the Node.js ecosystem.

Requirements

Nbb requires Node.js v12 or newer.

How does this tool work?

CLJS code is evaluated through SCI, the same interpreter that powers babashka. Because SCI works with advanced compilation, the bundle size, especially when combined with other dependencies, is smaller than what you get with self-hosted CLJS. That makes startup faster. The trade-off is that execution is less performant and that only a subset of CLJS is available (e.g. no deftype, yet).

Usage

Install nbb from NPM:

$ npm install nbb -g

Omit -g for a local install.

Try out an expression:

$ nbb -e '(+ 1 2 3)'
6

And then install some other NPM libraries to use in the script. E.g.:

$ npm install csv-parse shelljs zx

Create a script which uses the NPM libraries:

(ns script
  (:require ["csv-parse/lib/sync$default" :as csv-parse]
            ["fs" :as fs]
            ["path" :as path]
            ["shelljs$default" :as sh]
            ["term-size$default" :as term-size]
            ["zx$default" :as zx]
            ["zx$fs" :as zxfs]
            [nbb.core :refer [*file*]]))

(prn (path/resolve "."))

(prn (term-size))

(println (count (str (fs/readFileSync *file*))))

(prn (sh/ls "."))

(prn (csv-parse "foo,bar"))

(prn (zxfs/existsSync *file*))

(zx/$ #js ["ls"])

Call the script:

$ nbb script.cljs
"/private/tmp/test-script"
#js {:columns 216, :rows 47}
510
#js ["node_modules" "package-lock.json" "package.json" "script.cljs"]
#js [#js ["foo" "bar"]]
true
$ ls
node_modules
package-lock.json
package.json
script.cljs

Macros

Nbb has first class support for macros: you can define them right inside your .cljs file, like you are used to from JVM Clojure. Consider the plet macro to make working with promises more palatable:

(defmacro plet
  [bindings & body]
  (let [binding-pairs (reverse (partition 2 bindings))
        body (cons 'do body)]
    (reduce (fn [body [sym expr]]
              (let [expr (list '.resolve 'js/Promise expr)]
                (list '.then expr (list 'clojure.core/fn (vector sym)
                                        body))))
            body
            binding-pairs)))

Using this macro we can look async code more like sync code. Consider this puppeteer example:

(-> (.launch puppeteer)
      (.then (fn [browser]
               (-> (.newPage browser)
                   (.then (fn [page]
                            (-> (.goto page "https://clojure.org")
                                (.then #(.screenshot page #js{:path "screenshot.png"}))
                                (.catch #(js/console.log %))
                                (.then #(.close browser)))))))))

Using plet this becomes:

(plet [browser (.launch puppeteer)
       page (.newPage browser)
       _ (.goto page "https://clojure.org")
       _ (-> (.screenshot page #js{:path "screenshot.png"})
             (.catch #(js/console.log %)))]
      (.close browser))

See the puppeteer example for the full code.

Since v0.0.36, nbb includes promesa which is a library to deal with promises. The above plet macro is similar to promesa.core/let.

Startup time

$ time nbb -e '(+ 1 2 3)'
6
nbb -e '(+ 1 2 3)'   0.17s  user 0.02s system 109% cpu 0.168 total

The baseline startup time for a script is about 170ms seconds on my laptop. When invoked via npx this adds another 300ms or so, so for faster startup, either use a globally installed nbb or use $(npm bin)/nbb script.cljs to bypass npx.

Dependencies

NPM dependencies

Nbb does not depend on any NPM dependencies. All NPM libraries loaded by a script are resolved relative to that script. When using the Reagent module, React is resolved in the same way as any other NPM library.

Classpath

To load .cljs files from local paths or dependencies, you can use the --classpath argument. The current dir is added to the classpath automatically. So if there is a file foo/bar.cljs relative to your current dir, then you can load it via (:require [foo.bar :as fb]). Note that nbb uses the same naming conventions for namespaces and directories as other Clojure tools: foo-bar in the namespace name becomes foo_bar in the directory name.

To load dependencies from the Clojure ecosystem, you can use the Clojure CLI or babashka to download them and produce a classpath:

$ classpath="$(clojure -A:nbb -Spath -Sdeps '{:aliases {:nbb {:replace-deps {com.github.seancorfield/honeysql {:git/tag "v2.0.0-rc5" :git/sha "01c3a55"}}}}}')"

and then feed it to the --classpath argument:

$ nbb --classpath "$classpath" -e "(require '[honey.sql :as sql]) (sql/format {:select :foo :from :bar :where [:= :baz 2]})"
["SELECT foo FROM bar WHERE baz = ?" 2]

Currently nbb only reads from directories, not jar files, so you are encouraged to use git libs. Support for .jar files will be added later.

Current file

The name of the file that is currently being executed is available via nbb.core/*file* or on the metadata of vars:

(ns foo
  (:require [nbb.core :refer [*file*]]))

(prn *file*) ;; "/private/tmp/foo.cljs"

(defn f [])
(prn (:file (meta #'f))) ;; "/private/tmp/foo.cljs"

Reagent

Nbb includes reagent.core which will be lazily loaded when required. You can use this together with ink to create a TUI application:

$ npm install ink

ink-demo.cljs:

(ns ink-demo
  (:require ["ink" :refer [render Text]]
            [reagent.core :as r]))

(defonce state (r/atom 0))

(doseq [n (range 1 11)]
  (js/setTimeout #(swap! state inc) (* n 500)))

(defn hello []
  [:> Text {:color "green"} "Hello, world! " @state])

(render (r/as-element [hello]))

Promesa

Working with callbacks and promises can become tedious. Since nbb v0.0.36 the promesa.core namespace is included with the let and do! macros. An example:

(ns prom
  (:require [promesa.core :as p]))

(defn sleep [ms]
  (js/Promise.
   (fn [resolve _]
     (js/setTimeout resolve ms))))

(defn do-stuff
  []
  (p/do!
   (println "Doing stuff which takes a while")
   (sleep 1000)
   1))

(p/let [a (do-stuff)
        b (inc a)
        c (do-stuff)
        d (+ b c)]
  (prn d))
$ nbb prom.cljs
Doing stuff which takes a while
Doing stuff which takes a while
3

Also see API docs.

Js-interop

Since nbb v0.0.75 applied-science/js-interop is available:

(ns example
  (:require [applied-science.js-interop :as j]))

(def o (j/lit {:a 1 :b 2 :c {:d 1}}))

(prn (j/select-keys o [:a :b])) ;; #js {:a 1, :b 2}
(prn (j/get-in o [:c :d])) ;; 1

Most of this library is supported in nbb, except the following:

  • destructuring using :syms
  • property access using .-x notation. In nbb, you must use keywords.

See the example of what is currently supported.

Examples

See the examples directory for small examples.

Also check out these projects built with nbb:

API

See API documentation.

Migrating to shadow-cljs

See this gist on how to convert an nbb script or project to shadow-cljs.

Build

Prequisites:

  • babashka >= 0.4.0
  • Clojure CLI >= 1.10.3.933
  • Node.js 16.5.0 (lower version may work, but this is the one I used to build)

To build:

  • Clone and cd into this repo
  • bb release

Run bb tasks for more project-related tasks.

Download Details:
Author: borkdude
Download Link: Download The Source Code
Official Website: https://github.com/borkdude/nbb 
License: EPL-1.0

#node #javascript

Luna  Mosciski

Luna Mosciski

1600583123

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

sophia tondon

sophia tondon

1618971133

Top 10 VueJS Development Companies To Know In 2021-22

Vue.js is one of the most used and popular frontend development, or you can say client-side development framework. It is mainly used to develop single-page applications for both web and mobile. Famous companies like GitLab, NASA, Monito, Adobe, Accenture are currently using VueJS.

Do You Know?

Around 3079 companies reportedly use Vue.js in their tech stacks.
At GitHub, VueJS got 180.9K GitHub stars, including 28.5K GitHub forks.
Observing the increasing usage of VueJS and its robust features, various industry verticals are preferring to develop the website and mobile app Frontend using VueJS, and due to this reason, businesses are focusing on hiring VueJS developers from the top Vue.js development companies.

But the major concern of the enterprises is how to find the top companies to avail leading VueJS development service? Let’s move further and know what can help you find the best VueJS companies.

Read More - https://www.valuecoders.com/blog/technology-and-apps/top-10-vuejs-development-companies/

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Top VueJS App Development Company in USA

AppClues Infotech is the best & most reliable VueJS App Development Company in USA that builds high-quality and top-notch mobile apps with advanced methodology. The company is focused on providing innovative & technology-oriented solutions as per your specific business needs.

The organization’s VueJS developers have high experience and we have the capability of handling small to big projects. Being one of the leading mobile app development company in USA we are using the latest programming languages and technologies for their clients.

Key Elements:

· Total year of experience - 8+

· Employees Strength - 120+

· Hourly Rate - $25 – $45 / hr

· Location - New York, USA

· Successfully launched projects - 450+

VueJS Development Services by AppClues Infotech

· Custom VueJS Development

· Portal Development Solutions

· Web Application Development

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· VueJS Ecommerce Development

· SPA (Single Page App) Development

· VueJS Migration

Why Hire VueJS Developers from AppClues Infotech?

· Agile & Adaptive Development

· 8+ Years of Average Experience

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If you have any project ideas for VueJS app development then share your requirements with AppClues Infotech to get the best solution for your dream projects.

For more info:
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**

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