subtle.js

jQuery without jQuery and some more helpful functions

Highlights:

• Supports even IE9!
• $() and $$() element selectors
• Convinient methods: on, off, once, and trigger
• $.getListeners(element)
• Event delegation for vanilla Javascript
• $.extend and $.merge for different use cases
• Bulk functions $.properties, $.attributes, and $.style
• $.ready and $.fetch

Heavily inspired by:

• Bliss.js by Lea Veriou
• min.js by Remy Sharp
• bling.js by Paul Irish

Browser Support

Works in all browsers and IE >= 9, but only if WeakMap, Promise, and URL are polyfilled. https://polyfill.io/v3/polyfill.min.js?features=Promise%2CURL%2CWeakMap

Promise and URL are only used in $.ready, $.fetch, $.getScript, and $.defer. If you don't use them, you don't need those polyfills.

Without any polyfill, it works in all evergreen browers and not in IE.

If IE >= 11 is enough, then only Promise and URL need polyfills.

Side Note

Polyfills for Element.matches, Element.closest, NodeList.forEach, CustomEvent, and DOMException are included if they don't exist.

Installation

Install with yarn: yarn add opusonline-subtle.js

Usage

Examples

$$('#section a').on('click', function(event) {
    event.preventDefault();
});

$.style($('#section > h1'), {
    color: 'red',
    fontSize: '24pt',
    backgroundColor: 'black'
});

$('#section').find('p').forEach(…);

var test = {foo: {bar: 1}}; // runs smoothly even if test is undefined or empty or whatever
if ($.deep(test, 'foo.bar') === 1) {
    …
}

var testClone = $.clone(test);
testClone.foo.bar = 2;
log(test.foo.bar); // 1

var deferred = $.defer();
setTimeout(function() {
    deferred.resolve(true);
}, 5000);
deferred.then(…);

$.getScript('/scripts/polyfill.js', navigator.userAgent.indexOf('MSIE') > -1).then(function() {
    haveFun();
});

Methods

$(selector: String) => element|null

Returns DOM element if exists, else null.

element.find(selector: String) => NodeList

Returns a NodeList that is iteratable with forEach and has a length property. It really only retrieves child elements from the given element (See https://developer.mozilla.org/en-US/docs/Web/API/Element/querySelectorAll#User_notes). :scope is automatically injected if not used already. Good to know: if find returns an empty list you can still call forEach.

$('#selector').find('> p').forEach(…);

$$() => NodeList

Returns a NodeList that is iteratable with forEach and has a length property.

element.on(event, callback, [options]), element.off([event], [callback]), element.trigger(event), element.once(event, callback, [options]) => element

Event assigning on element(s). Classnames are supported. Good to know: You can still use addEventListener and removeEventListener. Goody: on, off, etc. are added to EventTarget which is the base not only for elements, but also for objects like XMLHttpRequest, FileReader, and others.

var elements = $$('#selector a');
elements.on('click.test', doStuff);
elements.trigger('click');
elements.off('.test');

elements.on({'focusin': onFocus, 'focusout': onBlur});

elements.on('canHazData', function(event) {
    log(event.detail); // {'foo': 'bar'}
});

elements.trigger('canHazData', {'foo': 'bar'});

window.on('scroll', nonBlockingFunction, {'passive': true}); // silently ignored if not supported (IE)

$.on(element, event, callback, [options]), $.off(element, [event], [callback]), $.trigger(element, event), $.once(element, event, callback, [options]) => element

Same as element.on() but another syntax. element can be an array of elements.

$.getListeners(element) => Object

Returns a list of event listeners for given element. Good to know: Events added with addEventListener and removeEventListener are also considered.

$('#test').on('click.test', function(){});
$.getListeners($('#test'));
// {
//     'click': [
//         {
//             'type': 'click',
//             'listener': function(){},
//             'handler': null,
//             'useCapture': false,
//             'classNames': ['test'],
//             'once': false
//         }
//     ]
// }

$.publish(), $.subscribe(), $.unsubscribe() => EventTarget

Convenient Pub/Sub event pattern on global scope.

$.subscribe('foo', function(event) {
    log(event.detail); // "bar"
});

$.publish('foo', 'bar'); // triggers CustomEvent with detail = 'bar'

$.unsubscribe('foo');

$.delegated(selector: String, callback)

This is my idea of using event delegation. That means, event handlers can already be added to a parent element like document, before the actual element is even added to the DOM.

$('ul').on('click', $.delegated('li > a', function(event) {
    event.preventDefault();
    doStuff(this); // this = a / event.delegateTarget = ul
}));

$.deep(object, properties: String) => value|undefined

Safely use multi-level objects without screwing up your app.

var test = {'foo': {'bar': 'baz'}};

$.deep(undef, 'foo.bar'); // undefined
$.deep(test, 'meh'); // undefined
$.deep(test, 'foo'); // {'bar': 'baz'}
$.deep(test, 'foo.bar'); // 'baz'
$.deep(test, 'foo.meh'); // undefined

$.extend(target, source, [deep = false]) and $.merge(target, source, [deep = false]) => target

This is both sugar and confusing at the same time. Bear with me! Extend simply takes a value from the source and adds it to the target. If it aleady exists, it gets replaced! Good to know: getter and setter are not invoked in contrast to Object.assign!

var target = {a: {b: 1, c: 2}};
var source = {a: {d: 2, c: 3}};

$.extend(target, source); // {a: {d: 2, c: 3}} - target.a is replaced with source.a!!!

Now $.merge comes into play.

var target = {a: {b: 1, c: 2}};
var source = {a: {d: 2, c: 3}};

$.merge(target, source); // {a: {b: 1, c: 3, d: 2}} - it merges source.a to target.a

Have you noticed the 3rd parameter deep? This makes sense for multi-level objects. If deep is true, a real clone is created.

var test = {'foo': {'bar': 'baz'}};
var extended = $.extend({}, test); // {'foo': {'bar': 'baz'}}
var extendedDeep = $.extend({}, test, true); // {'foo': {'bar': 'baz'}}

test.foo.bar = 'changed!';

log(extended.foo.bar); // 'changed!'
log(extendedDeep.foo.bar); // still 'baz'

$.clone(object) => Object

Guess what? This makes a deep copy of the original object including class prototypes. It can be even used on special objects like Dates or RegExp. Good to know: clone is a deep extend.

var test = {'foo': {'bar': 'baz'}};
var clone = $.clone(test);

test.foo.bar = 'changed!';

log(clone.foo.bar); // still 'baz'

function MyClass(message) {
    this.number = 1;
}
var a = new MyClass();
var b = $.clone(a);

a.number = 5;

log(b.number); // still 1 !!!

$.noop() => Function

Noop stands for no operation. This is simply an empty function.

$.type(object) => String

Returns the base type name of the given object.

$.type('hello world!'); // String
$.type(1); // Number
$.type(true); // Boolean
$.type(function() {}); // Function
$.type(new Date()); // Date
$.type(/abc/); // RegEx
$.type(null); // Null
$.type(undefined); // Undefined
$.type(document); // HTMLDocument
$.type(new Uint8Array(1)); // Uint8Array

$.properties(element, properties, [whitelist]) => element

Set properties to an existing element or object. Works basically the same way as $.extend does, but has some nice extra features. Similar jQuery method: jQuery.fn.prop

$.properties($('button.next'), {
    'textContent': 'Next Step',
    'disabled': false,
    'onclick': function() { MyApp.next() }
});

$.properties($('#new').style, $('#old').style, ['color', 'backgroundColor', 'fontSize']);
$.properties($('#new').style, $('#old').style, /color/i);
$.properties($('#new').style, $('#old').style, function(property) {
    if (property.indexOf('color') > -1) {
        return true;
    }
    return false;
});

$.attributes(element, attributes, [whitelist]) => element

Works the same way as $.properties BUT attributes are added with Element.setAttribute method. Similar jQuery method: jQuery.fn.attr

$.style(element, styles, [whitelist]) => element

Works the same way as $.properties and $.attributes. Similar jQuery method: jQuery.fn.css

$.style($('#h1'), {
    'color': '#abc',
    'fontSize': '24pt',
    'textTransform': 'uppercase'
});

$.style($('#new'), $('#old').style, ['color', 'backgroundColor', 'fontSize']);

$.each(obj = Object|Array, callback, [context]) => Boolean

You might already know it from jQuery.each BUT there's one main difference! The callback parameter order is changed in the same way as Array.forEach! The first callback parameter is the current value. This allows to easily walk through object entries. Good to know: The loop can be stopped by returning false.

var test = {'a': {'count': 1}, 'b': {'count': 2}, 'c': {'count': 3}, 'd': {'count': 4}, 'e': {'count': 5}};
var sum = 0;
$.each(test, function(entry) {
    sum += entry.count;
});
var search = -1;
$.each([1, 2, 3, 4, 5], function(value, index) {
    if (value === 4) {
        search = index;
        return false;
    }
});

$.spliceInPlace(array, item) => array

A convenient method to remove all item ocurrencies from a given array in place.

var A = {'letter': 'a'};
var B = {'letter': 'b'};
var C = {'letter': 'c'};
var lookup = [A, B, C];
// instead of
lookup.splice(lookup.indexOf(B), 1);
// you can do
$.spliceInPlace(lookup, B);

$.isPrimitive(anything) => Boolean

$.isPrimitive(100); // true
$.isPrimitive(new Number(100)); // false

var str = 'string';
var strObject = new String('string');
$.type(str); // String
$.type(strObject); // String
$.isPrimitive(str); // true
$.isPrimitive(strObject); // false!!!

$.ready([callback]) => Promise

Promise that resolves whenever DOMContentLoaded is true. The callback gets fired, but you can also use it the Promise way.

$.ready(function init() {
    // page is fully loaded, start your app
});

Promise.all([
    $.ready(),
    fetch('/analytics.php')
]).then(function() {
    // work done, start playing
});

$.params(object) => String

Serializing an object. Needed for $.fetch.

$.params({'foo':'a b c'}); // foo=a%20b%20c
$.params({'data': [1, 2, 3, {'foo': 'bar'}]}); // data%5B0%5D=1&data%5B1%5D=2&data%5B2%5D=3&data%5B3%5D%5Bfoo%5D=bar

$.fetch(url: String, [options]) => Promise

$.fetch is the equivalent of modern javascript fetch but since it's using XMLHttpRequest under the hood, some goodies are provided.

options Object:

• method (String): GET, POST, PUT, DELETE, OPTIONS, HEAD, whatever is possible; defaults to GET
• params (Object|URLSearchParams): serialized to URL query
• headers (Object): key value pairs that will getbe set as request headers
• user and password (String): add user and password to host in URL for authentication
• cache (Boolean): enforce a fresh response; appends _=; defaults to false
• body (String|Blob|BufferSource|FormData|URLSearchParams|ReadableStream): payload sent as POST or PUT
• type (String): json; only 'json' is supported; body can be an Object or JSON String.
• signal (AbortSignal): Abort pattern used in fetch; when $.fetch is aborted it throws a DOMException with name AbortError; Attention: add polyfill for older browsers (e.g. https://polyfill.io/v3/polyfill.min.js?features=AbortController)
• all XHR settings like onload, onreadystatechange, onerror, onabort, ontimeout, overrideMimeType, upload Object, timeout, withCredentials, etc.

resolve holds the xhr object with xhr.response as the desired response content.

reject is an Error object that has status = xhr.status, message = xhr.statusText and the xhr object set or it is a DOMException for Network, Timeout, and Abort Errors with the xhr object.

$.fetch('/data')
    .then(function(xhr) {
        log(xhr.responseURL); // full absolute URL like https://example.com/data
        log(xhr.status, xhr.statusText); // hopefully it's 200 OK
        log(xhr.response); // the actual response
        log(xhr.getAllResponseHeaders());
        log(xhr.getResponseHeader('content-type'));
    })
    .catch(function(error) {
        log(error.status); // same as xhr.status, e.g. 404
        log(error.message); // same as xhr.statusText, e.g. Not Found
        log(error.xhr); // the full xhr object
        log(error.xhr.responseURL);
    });

var postData = {foo: 'bar'};
$.fetch('/data', {'method': 'POST', 'body': postData}).then(…).catch(…); // postData object is serialized with $.params()
$.fetch('/data', {'method': 'PUT', 'body': postData}).then(…).catch(…);

$.fetch('/data', {'method': 'POST', 'type': 'json', 'body': postData}).then(…).catch(…);
$.fetch('/data', {'method': 'POST', 'headers': {'content-type': 'application/json'}, 'body': JSON.parse(postData)}).then(…).catch(…); // same as above

var queryParams = {'q': 'dev', 'page': 2};
$.fetch('/search', {'params': queryParams, 'cache': false}).then(…).catch(…); // queryParams object is serialized with $.params() and appended to url, e.g. https://myserver/sarch?q=dev&page=2&_=1586807957258

$.fetch('https://myserver.com/private/data', {'user': 'u', 'password': 'pass'}).then(…).catch(…); // https://u:[email protected]/private/data

$.fetch('/data', {'onload': function(event) { // use xhr.onload as success callback
    var response = event.target.response;
}}).then(…).catch(…);

$.fetch('/data', {'onprogress': function(event) { // use xhr.onload as success callback
    var progress = event.loaded / event.total;
    log(progress);
}}).then(…).catch(…);

var data = new FormData();
var file = new Blob(['Demo'], {'type': 'text/plain'});
data.append('file', file, 'demo.txt');
$.fetch('/upload', {'method': 'POST', 'body': data, 'upload': {'onprogress': function(event) {
    var uploadProgress = event.loaded / event.total;
    log(uploadProgress);
}}});

$('myForm').on('submit', function(event) {
    event.preventDefault();
    var form = this;
    $.fetch('/settings', {'method': 'POST', 'body': form}).then(…).catch(…); // HTMLFormElement will be sent as FormData
});

var controller = new AbortController();
$.fetch('/bigData', {'signal': controller.signal}).then(…).catch(function(error) {
    if (error.name === 'AbortError') {
        …
    }
});
controller.abort();

$.getJSON(url: String, [options]) => Promise

This is $.fetch, but the loaded serialized JSON String is parsed. Throws an error if JSON is malformed. options Object is exactly the same as for $.fetch.

$.getJSON('/data.json')
    .then(function(data) {
        log(data.foo);
    })
    .catch(function(error) {
        log(error.name); // SyntaxError
        log(error.message); // Unexpected token… or whatever
    });

$.getScript(url: String, [condition: Boolean]) => Promise

Loads a script and resolves when script can be used. Optional condition reads: if then load else skip.

var url = "https://cdnjs.cloudflare.com/ajax/libs/es5-shim/4.3.1/es5-sham.min.js";
$.getScript(url, !Array.prototype.forEach).then(…).catch(…);

$.defer() => Promise

Gorgious Lea Verou worked this out. See http://lea.verou.me/2016/12/resolve-promises-externally-with-this-one-weird-trick/

var deferred = $.defer();
//
deferred.then(function(done) {
    // party!
});

deferred.resolve(true); // parameter is optional

$.debounced(fn, wait: Milliseconds, immediate: Boolean)

My optimized version of debounced function. Read here why you need this! Immediate is false by default. If true, fn is called at the first trigger instead of the last.

window.on('resize', $.debounced(updateChart, 250));