1566206277
In this article you’ll learn how to use ARIA and Vue.js to make your form error messages and instructions more accessible to all of your users.
Any developer who is building forms with accessibility in mind needs to understand some important differences between how a sighted user and a screen reader user “reads” web forms. The first is that there is a “hidden” dimension of your web page known as the “accessibility tree”. The accessibility tree is a DOM-like structure that enable the screenreader get information from your browser.
Using ARIA, the developer can customize certain aspects of the page to enhance the accessibility of your content and overall experience for screenreader users.
A second difference is that the two most popular screenreaders use (or can use) a specific mode known as “forms” or “focus” mode to navigate web forms more easily. While in forms mode, the screenreader enables the user to navigate among the form’s interactive controls with the keyboard. When the focus arrives at a control, the screenreader reads both the input and and the associated label. That’s pretty slick, isn’t it?
Forms mode sounds pretty useful — but what about the other items that we often add to forms, such as validation error messages, or instructions we might want to provide for fields (hints for required formats, acceptable or required characters, etc.). If the developer places these within an element that is not inherently focusable, such as a <div>
or <p>
, a screenreader in forms mode will skip right over them. That’s not what we want! So how do we ensure that screenreader will read this additional (and ofen essential) information?
By far the easiest way to make your validation error messages accessible is to make them a child of the <label>
element. By making the error message part of the label, the message becomes part of the accessible name for the control — in this case, the input element – and will be read when ever the control has focus. Of course, you will want to use Vue’s v-show directive to hide the error message until there is a validation error. Since it utilizes CSS’s display: none, v-show will also keep the error message out of the accessibility tree, which hides it from screen readers.
For some, this can be a quick and easy solution. It doesn’t require any ARIA, keeps your code simple, and minimizes the possibilities for coding errors.
But what if you would rather not have your error messages within the <label>
element? There might be good reasons for this. For example, tampering with the control’s accessible name when there is an error might seem like a kludge. Or perhaps you want to place the messages someplace else relative to the control, or even display them within their own list or block element (both of which are invalid inside <label>
).
If you prefer to keep accessible name “pure”, or want more flexibility, you can still make your error messages accessible. ARIA (“Accessible Rich Internet Applications”) attributes enable developers to add semantics where HTML alone isn’t sufficient. ARIA attributes have no effect on a sighted user’s web experience. But they do affect how screen readers interpret a page through the accessibility tree.
As luck would have it, ARIA provides an attribute that enables developers to associate other html elements with a form field: aria-describedby
. To provide field instructions, simply add the aria-describedby
attribute to the field input with the id
of each element you want to link with the input
. The id
s should be space-separated and entered in the order you want them read.
<label for="first_name">First Name:</label>
<input id="first_name" type="text" aria-describedby="first_name-instructions">
<div id="first_name-instructions">maximum length 30 characters</div>
Wen the focus is placed on the <input>
, the screenreader will say something like this:
“First name colon edit. maximum length 30 characters edit”
Now that we have explicitly associated additional instructions with our field, we also want to add an error messages. Let’s try this:
<div id="first_name-error">
Please enter a valid project name.
</div>
<label for="first_name">First Name:</label>
<div id="first_name-instructions">maximum length 30 characters</div>
<input id="first_name" name="first_name" type="text" aria-describedby="first_name-instructions first_name-error">
And with one simple attribute, we have added an error message and associated it with the form input.
But we’re not done yet. First, we don’t want the error message to be displayed and read all of the time; we only want to see or hear it when there is an error. This example uses the excellent Vuelidate library.
<div id="first_name-error" v-show="first_name.$error">
Please enter a valid project name.
</div>
<label for="first_name">First Name:</label>
<div id="first_name-instructions">maximum length 30 characters</div>
<input id="first_name" name="first_name" type="text" v-model="$v.first_name.$model" :aria-invalid="$v.first_name.$invalid" aria-describedby="first_name-instructions first_name-error">
Now we have an error message that is associated with the field input, but will be visually hidden unless a validation error is detected. Since we are using v-show
, we might expect the message to be hidden from screen readers as well, and under most circumstances, it will. But here we encounter a feature of aria-describedby
that might seem counter-intuititive: by default, it will read a referenced element even when that element is hidden. (it makes no difference whether this is done by css or aria-hidden). To make our solution work as intended, we need to make aria-describedby
dynamic so that it adds the id for the error message only when therre is an error. Of course Vue.js makes this quite easy. Have a look at this example:
signup-form.html
<div id="first_name-error" v-show="first_name.$error">
Please enter a valid first name
</div>
<label for="first_name">First Name:</label>
<div id="first_name-instructions">maximum length 30 characters</div>
<input id="first_name" name="first_name" type="text" v-model="$v.first_name.$model" :aria-invalid="$v.first_name.$invalid" :aria-describedby="describedBy('first_name')">
main.js
methods: {
// generate aria-describedby reference ids
describedBy(field) {
const inst = `${field}-instructions`
// field.$error is a boolean computed property returned by Vuelidate
// if there is an error, valErr becomes the field id. Otherwise it is an empty string.
const valErr = field.$error
? `${field}-error`
: ''
//trim and replace double-spaces with single space
let refString = ` $ {valErr} ${inst}`.replace(/\s+/g,' ').trim()
return refString
}
// a basic error message builder
vMessage(v, field) {
let message = ''
let errors = []
if ($v.$error)) {
// get error types from Vuelidate $params
let errorTypeKeys = Object.keys($v["$params"])
// build errors array
for (const key of errorTypeKeys) {
if ($v[key] === false) {
errors.push(key)
}
}
//build comma=separated string from array
let errorString = errors.length > 1
? errors.join(', ')
: errors[0]
// convert to more readable message
errorString = errorString
.replace('required', 'This is a required field')
.replace('url', 'The url is invalid')
.replace('email', 'The email address is invalid')
.replace('minLength', 'Input does not meet minimum length')
message = `${errorString}.`
}
return messsage
}
}
Now we have a dynamic aria-describedby
attribute that is bound to the output of the describedBy()
method. describedBy()
takes the field name as a parameter; determines whether the field input is valid; and returns the appropriate string of space-separated list of ids. If there is an error, and the focus is placed on the <input>
, aria-describedby
will reference both the error message and the instructions, and the screen reader will announce both. Otherwise, the screen reader will announce only the instructions (the <label>
will be announced regardless).
Developers should be aware that, as with web browsers, screen readers are not all the same. They can interpret html or ARIA in their own unique way, have their own feature sets, and their functionality can vary when used with different web browsers. For example, both JAWS and NVDA support both forms (focus) mode and aria-describedby, while Voiceover supports aria-describedby, but it does not have a focus or forms mode. NVDA seems to work most reliably with Firefox, while Voiceover seems to work best with Safari.
While there is broad support for aria-describedby
among screen readers and (modern) web browsers, it does have some behaviors that developers should be aware of. For example, in addition to reading hidden referenced elements (above), aria-describedby
seems to disregard semantics; it reads referenced elements as a continuous string. If your instructions and messages contain lists or other nested elements, the semantics will be ignored, and in some cases, the content might not be read at all. Therefore, it is best to keep message content short and simple, and use punctuation. For a complete list of caveats, see the Scott O’Hara article cited at the end of this article.
Using aria-describedby for validation error messages might not seem like an especially elegant solution. Of course, ARIA is still relatively young. In late-2017, ARIA 1.1 added the aria-errormessage
attribute, which is intended to deal specifically with validation error messages. When it gains support in screen readers and browsers, aria-errormessage
will be used together with the aria-invalid
attribute to provide a more coherent method for reading out the error message. But as of this writing, support for aria-errormessage
is still poor to nonexistent, so for now, developers should user aria-describedby
to make form field instructions and errors more accessible.
All of the above should make it clear that neither automated tools nor visually viewing the site yourself can tell you whether your forms are working as intended, and are providing an inclusive experience for all users. The only way to ensure this is by testing with a screen reader. So fire up a copy of NVDA, Voiceover (both free), or JAWS (if you can afford it), get under “the hood” and start exploring the non-visual dimension of the web. You may be surprised by what you hear — and discover.
Recommended Reading
☞ How to use PWA plugin in Vue CLI 3.0
☞ How to Using Cypress with Django and Vue for integration testing in GitLab CI
☞ Going Serverless with Vue.js
☞ What React Hooks Mean for Vue developers
☞ Build a Single-Page App with Go and Vue
☞ Server Side Pagination with Vue.js and Node
☞ Build Your First PWA with Vue and TypeScript
#vue-js #javascript
1625232484
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.
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.
• 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.
• 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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
#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
1632537859
Not babashka. Node.js babashka!?
Ad-hoc CLJS scripting on Node.js.
Experimental. Please report issues here.
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:
Nbb requires Node.js v12 or newer.
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).
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
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
.
$ 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
.
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.
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.
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"
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]))
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.
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:
:syms
.-x
notation. In nbb, you must use keywords.See the example of what is currently supported.
See the examples directory for small examples.
Also check out these projects built with nbb:
See API documentation.
See this gist on how to convert an nbb script or project to shadow-cljs.
Prequisites:
To build:
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
1618971133
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/
#hire vue js developer #hire vue.js developers #hire vue.js developer, #hire vue.js developers, #vue js development company #vue.js development company
1600583123
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
1600308055
Laravel 8 form validation example. In this tutorial, i will show you how to submit form with validation in laravel 8.
And you will learn how to store form data in laravel 8. Also validate form data before store to db.
https://laratutorials.com/laravel-8-form-validation-example-tutorial/
#laravel 8 form validation #laravel 8 form validation tutorial #laravel 8 form validation - google search #how to validate form data in laravel 8 #form validation in laravel 8