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Create an instance of a jQuery plugin

I have several pages which I wish to allow the the user to inline edit many fields and update the server DB. To implement this, my intent is to create a jQuery plugin which I can do the typical passing of the configuration options and uses ajax to save the results.
(function($){
var methods = {
init : function (options) {return this.each(function () {/* ... */});},
method1 : function () {return this.each(function () {/* ... */});},
method2 : function () {return this.each(function () {/* ... */});}
};
$.fn.myEditPlugin= function(method) {
if (methods[method]) {
return methods[method].apply(this, Array.prototype.slice.call(arguments, 1)); //Line 10
} else if (typeof method === 'object' || ! method) {
return methods.init.apply(this, arguments); //Line 12
} else {
$.error('Method ' + method + ' does not exist on jQuery.myEditPlugin');
}
};
}(jQuery)
);
For each individual page, there are several options which are common to all (i.e. the url endpoint, the record's primary key, etc) and I would rather not duplicate each when applying the plugin.
Originally, I was just going to define a function on each page which takes some input and applies the common options to each.
function wrapEdit(e,options) {
options.url='/page1/etc';
options.pk=document.getElementById('pk').value;
return $(e).myEditPlugin(options);
}
wrapEdit('.someclass',{foo:123});
It doesn't seem all that professional to me, so in my obsessive quest, thought I would make a class which I could pass the common options to and it would apply the plugin.
class WrapEdit(options)
{
constructor(options) {
this.options = options;
}
this.applyIndividualOptions=function(e, options) {
return $(e).myEditPlugin(Object.assign({}, this->options, options));
}
}
var wrapEdit=new WrapEdit({url: '/page1/etc', pk: document.getElementById('pk').value});
wrapEdit.applyIndividualOptions('.someclass',{foo:123});
Better, but not very jQueryish as I will be passing the select element instead of directly applying the plugin to elements typical of jQuery.
Is it possible to create an instance of a jQuery plugin which keeps previously defined data? Maybe something like the following:
$.myEditPlugin({url: '/page1/etc', pk: document.getElementById('pk').value});
$('.someclass').myEditPlugin({foo:123}); //Will also pass previously defined url and pk to myEditPlugin
Or maybe best to create a custom jQuery plugin per page which just adds the extra options and initiates the real plugin...
$.fn.myEditPluginInstance = function(options) {
return this.myEditPlugin(Object.assign({url: '/page1/etc', pk: document.getElementById('pk').value}, options));
};

Creating a function to be called against a jquery collection
The basic idea is to define a new property (function) in jQuery.fn, before any call to your plugin is made (In other words, any code related to the application is executed). You can use an "Immediately Invoked Function Expressions" (a.k.a. IIFEs) to fence your plugin API in. Then you have to loop over the collection and execute any code your plugin needs to apply on the collection items.
Basic skeleton:
(function ($) {
// Enclosed scope (IIFE)
// You can define private API/variables in here
// …
// Once your plugin API is ready, you have to apply the magic to each item
// in the collection in some ways. You must add a property to jQuery.fn object.
$.fn.myAwesomePlugin = function(Opt) {
var defaultConfig = {option1: 'someValue' /*, …*/};
// Eval supplied Opt object (Validate, reject, etc.)
// If all goes well, eventually merge the object with defaults.
$.extend(defaultConfig, Opt);
// Apply the magic against each item in the jQuery collection
// (Your plugin may not need to use "each" function though)
// Return the jQuery collection anyway to keep chaining possible.
// Once again, this is not required, your plugin may return something else depending on the options passed earlier for instance.
return this.each(function(el, idx) {
// Your plugin magic applied to collection items…
});
}
})(jQuery);
You should be able to call your plugin $('someSelector').myAwesomePlugin(); right after the declaration.
Simple implementation example:
(function ($) {
let required = {url: null, pk: null}
// Function to be executed upon first call to the plugin
, populateCommons = () => {
let ep = $('#someNode').data('endpoint')
, pk = document.querySelector('#pk')
;
// Basic tests to alert in case the page
// doesn't comply with the plugin requirements
if( typeof ep !== 'string' || !/^\/[a-z]+/.test(ep) || !pk) {
throw ` "myEditPlugin" init phase error:
Detected endpoint: '${ep}'
Is PK value found: ${!!pk}
`;
}
[required.url, required.pk] = [ep, +pk.value];
};
$.fn.myEditPlugin = function(Opt) {
let allOpts;
// First call will trigger the retrival of common data
// that should be available as static data somewhere every page source.
!required.url && populateCommons();
allOpts = $.extend({}, Opt, required);
return this.each(function(el, idx) {
// Your logic here, request
console.log("Payload is", allOpts);
});
}
})(jQuery);
function debounce(fn, time) {
debounce.timer && (clearTimeout(debounce.timer));
debounce.timer = setTimeout(() => (fn(), debounce.timer = null), time);
}
$('[type="text"]').keydown(function(e){
debounce(() => this.value && $(this).myEditPlugin({foo:this.value, bar: 'Contextual value'}), 2000);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input id="pk" type="hidden" value="5">
<div id="someNode" data-endpoint="/api/endpoint">
Editing the below input will trigger the plug-in code
</div>
<input type="text" title="Edit me"/>
Related documentation here

Access plugin instance using the id of the DOM Element

The concept is to have 2 plugins one for form and another for button. I want to bind all forms in my page to JQuery plugin that will handle some jobs let say that this is my plugin
$.fn.PluginForm = function (Options) {
var o = jQuery.extend({
SomeOption: 1
}, Options);
var Validate = function(){
if(o.SomeOption == 1) return true;
else return false;
};
$(this).on('submit', function(e) {
e.preventDefault();
//some code here
});
};
The form actually doesn’t have button in my case the post is triggered from another control. This is because of the structure of the application I want to build. The button plugin is:
$.fn.PluginButton = function (Options) {
var o = jQuery.extend({
Actions: [],
FormID: ''
}, Options);
$(this).click(function(){
var Form = $('#' + o.FormID);
if(Form.length > 0 && Form.PluginForm.Validate()) {
Form.submit();
//do something
}
else{
//do something else
}
});
};
What I want to succeed is to invoke the validation function on the Form element but I don’t want to invoke another instance of the PluginForm. Something like $('#' + o.FormID).PluginForm.Validate()
All this must be as plugin because there will be a lot of forms in the same page and a lot of buttons. Also there will be a lot of buttons that can invoke submit on the same form but with different options. That’s why I want to invoke one time the instance of the form. Also the controls that will be validated will be passed as parameter in the options of the PluginForm. Something like this $('#' + o.FormID).PluginForm({ Action: ‘Validate’ }) is not an option because will lose the initial parameters of the PluginForm.

You can save the plugin instance in the .data() structure on the element, and then call it back. Most of plugins use it that way.
/*!
* jQuery lightweight plugin boilerplate
* Original author: #ajpiano
* Further changes, comments: #addyosmani
* Licensed under the MIT license
*/
// the semi-colon before the function invocation is a safety
// net against concatenated scripts and/or other plugins
// that are not closed properly.
;(function ( $, window, document, undefined ) {
// undefined is used here as the undefined global
// variable in ECMAScript 3 and is mutable (i.e. it can
// be changed by someone else). undefined isn't really
// being passed in so we can ensure that its value is
// truly undefined. In ES5, undefined can no longer be
// modified.
// window and document are passed through as local
// variables rather than as globals, because this (slightly)
// quickens the resolution process and can be more
// efficiently minified (especially when both are
// regularly referenced in your plugin).
// Create the defaults once
var pluginName = "defaultPluginName",
defaults = {
propertyName: "value"
};
// The actual plugin constructor
function Plugin( element, options ) {
this.element = element;
// jQuery has an extend method that merges the
// contents of two or more objects, storing the
// result in the first object. The first object
// is generally empty because we don't want to alter
// the default options for future instances of the plugin
this.options = $.extend( {}, defaults, options) ;
this._defaults = defaults;
this._name = pluginName;
this.init();
}
Plugin.prototype = {
init: function() {
// Place initialization logic here
// You already have access to the DOM element and
// the options via the instance, e.g. this.element
// and this.options
// you can add more functions like the one below and
// call them like so: this.yourOtherFunction(this.element, this.options).
},
yourOtherFunction: function(el, options) {
// some logic
}
};
// A really lightweight plugin wrapper around the constructor,
// preventing against multiple instantiations
$.fn[pluginName] = function ( options ) {
return this.each(function () {
if (!$.data(this, "plugin_" + pluginName)) {
$.data(this, "plugin_" + pluginName,
new Plugin( this, options ));
}
});
};
})( jQuery, window, document );
taken from: https://github.com/jquery-boilerplate/jquery-patterns/blob/master/patterns/jquery.basic.plugin-boilerplate.js
also there are more jquery plugin design patterns that may fit more for your plugin at http://jqueryboilerplate.com/.

How to reference a function defined inside prototype

I am trying to add a functionality to a web page that uses a jquery library which doesn't seem to have any documentation. (unknown origin) my problem is mainly due to the lack of understanding on jquery plugin model and/or inner workings of javascript.
1. the plugin is initiated as follows
jQuery('div.carousel').scrollGallery({
mask: 'div.mask',
slider: 'div.slideset',
slides: 'div.slide', ............ });
2. the plugin is defined in jquery as follows
;(function($){
function ScrollGallery(options) {
this.options = $.extend({
mask: 'div.mask', ...... }, options);
this.init();
3. in the Object.prototype declaration i see the following function numSlide defined.
ScrollGallery.prototype = {
....................
numSlide: function(c) {
if(this.currentStep != c) {
this.currentStep = c;
this.switchSlide();
}
},
.......... };
Question.
How do i reference numSlide(int) function externally?.
I tried the following methods and it did not work.
myx = jQuery('div.carousel').scrollGallery({ // var myx was added in the global scope
myx.numSlide(1); //error undefined is not a function
i tried adding return this; at the end of myx = jQuery('div.carousel').scrollGallery({ but it still returns the jQuery object.
i also tried
jQuery.scrollGallery().numSlide(2); //error undefined is not a function
jQuery.scrollGallery.numSlide(2); //same error
Do i need to add LIGHT BULB
// jquery plugin
$.fn.scrollGallery = function(opt){
return this.each(function(){
$(this).data('ScrollGallery', new ScrollGallery($.extend(opt,{holder:this})));
});
};
}(jQuery));
ANSWER (I think)
it looks like the ScrollGalary object is stored in a data for the selector. So i believe i can do the following jQuery('selector').data('ScrollGallery').numSlide(2);
I decided to post this anyway in-case if anyone in the future had a similar gullible situation.

One way of doing this will be to initiate ScrollGallery object first and then use it.
var test = new ScrollGallery();
test.numSlide();
if you want to extend jQuery and use the function you can assign it as follows
$.fn.scrollGallery = new ScrollGallery();
and use it
$("window").scrollGallery.numSlide();

Is it a good practice to store jquery plugin configuration in data?

I want to create jQuery plugin with config (for example plugin myplugin).
Than call $(elem).myplugin(config); After that I want to call methods from this plugin like $(elem).myplugin().method() with already stored config.
My offer is something like that:
(function($) {
$.fn.myplugin = function(options) {
var $this = $(this);
var getOptions = function() {
return $this.data('myplugin');
};
var initOptions = function(opt) {
$this.data('myplugin', opt);
};
var setOption = function(key, value) {
$this.data('myplugin')[key] = value;
}
var updateBorderWidth = function() {
$this.css('border-width',
getOptions().borderWidth * getOptions().coeficient);
};
var init = function(opt) {
initOptions(opt);
updateBorderWidth();
}
function changeBorder(width) {
setOption('borderWidth', width)
updateBorderWidth();
}
if(options) {
init(options);
}
return {
changeBorder : changeBorder
};
}
})(jQuery);
And usage:
$(function() {
var item1 = $('#test1').myplugin({ coeficient: 1, borderWidth: 1 });
var item1 = $('#test2').myplugin({ coeficient: 2, borderWidth: 1 });
$('#btn').click(updateBorder);
});
function updateBorder() {
$('#test1').myplugin().changeBorder($('#inpt').val());
$('#test2').myplugin().changeBorder($('#inpt').val());
}
Example: http://jsfiddle.net/inser/zQumX/4/
My question: is it a good practice to do that?
May be it's incorrect approach. Can you offer better solution?

Edit:
After searching for threads on jQuery plugin template I found these Boilerplate templates (updated) which are more versatile and extensive designs than what I've offered below. Ultimately what you choose all depends on what your needs are. The Boilerplate templates cover more use cases than my offering, but each has its own benefits and caveats depending on the requirements.
Typically jQuery plugins either return a jQuery object when a value is passed to them as in:
.wrap(html) // returns a jQuery object
or they return a value when no parameter is passed in
.width() // returns a value
.height() // also returns a value
To read your example calling convention:
$('#test1').myplugin().changeBorder($('#inpt').val());
it would appear, to any developer who uses jQuery, as though two separate plugins are being utilized in tandem, first .myplugin() which one would assume will return a jQuery object with some default DOM maniplulation performed on #test1, then followed by .changeBorder($('#inpt').val()) which may also return a jQuery object but in the case of your example the whole line is not assigned to a variable so any return value is not used - again it looks like a DOM manipulation. But your design does not follow the standard calling convention that I've described, so there may be some confusion to anyone looking at your code as to what it actually does if they are not familiar with your plugin.
I have, in the past, considered a similar problem and use case to the one you are describing and I like the idea of having a convenient convention for calling separate functions associated with a plugin. The choice is totally up to you - it is your plugin and you will need to decide based on who will be using it, but the way that I have settled on is to simply pass the name of the function and it's parameters either as a separate .myplugin(name, parameters) or in an object as .myplugin(object).
I typically do it like so:
(function($) {
$.fn.myplugin = function(fn, o) { // both fn and o are [optional]
return this.each(function(){ // each() allows you to keep internal data separate for each DOM object that's being manipulated in case the jQuery object (from the original selector that generated this jQuery) is being referenced for later use
var $this = $(this); // in case $this is referenced in the short cuts
// short cut methods
if(fn==="method1") {
if ($this.data("method1")) // if not initialized method invocation fails
$this.data("method1")() // the () invokes the method passing user options
} else if(fn==="method2") {
if ($this.data("method2"))
$this.data("method2")()
} else if(fn==="method3") {
if ($this.data("method3"))
$this.data("method3")(o) // passing the user options to the method
} else if(fn==="destroy") {
if ($this.data("destroy"))
$this.data("destroy")()
}
// continue with initial configuration
var _data1,
_data2,
_default = { // contains all default parameters for any functions that may be called
param1: "value #1",
param2: "value #2",
},
_options = {
param1: (o===undefined) ? _default.param1 : (o.param1===undefined) ? _default.param1 : o.param1,
param2: (o===undefined) ? _default.param2 : (o.param2===undefined) ? _default.param2 : o.param2,
}
method1 = function(){
// do something that requires no parameters
return;
},
method2 = function(){
// do some other thing that requires no parameters
return;
},
method3 = function(){
// does something with param1
// _options can be reset from the user options parameter - (o) - from within any of these methods as is done above
return;
},
initialize = function(){
// may or may not use data1, data2, param1 and param2
$this
.data("method1", method1)
.data("method2", method2)
.data("method3", method3)
.data("destroy", destroy);
},
destroy = function(){
// be sure to unbind any events that were bound in initialize(), then:
$this
.removeData("method1", method1)
.removeData("method2", method2)
.removeData("method3", method3)
.removeData("destroy", destroy);
}
initialize();
}) // end of each()
} // end of function
})(jQuery);
And the usage:
var $test = $('#test').myplugin(false, {param1: 'first value', param2: 'second value'}); // initializes the object
$test.myplugin('method3', {param1: 'some new value', param2: 'second new value'}); // change some values (method invocation with params)
or you could just say:
$('#test').myplugin(); // assume defaults and initialize the selector

Passing parameters to javascript via data attributes is a great pattern, as it effectively decouples the Javascript code and the server-side code. It also does not have a negative effect on the testability of the Javascript code, which is a side-effect of a lot of other approaches to the problem.
I'd go as far as to say it is the best way for server-side code to communicate with client-side code in a web application.

jQuery Plugin Authoring - Set different options for different elements

I have created a jQuery plugin that works great with the exception of being able to call the plugin on different objects and each object retaining the options it was given. The problem is that if I call the plugin on one object, say:
$('#myDiv1').myPlugin({
option1: 'some text',
option2: true,
option3: 'another option value'
});
then call the plugin again on another object, say:
$('#myDiv2').myPlugin({
option1: 'different text',
option2: false,
option3: 'value for myDiv2'
});
Then if I go back and try to do something with #myDiv1 that needs its original options to still be intact, ie:
$('#myDiv1').myPlugin.update();
it won't have it's original options, but they will be overridden by the options for #myDiv2. What's the proper way to do this so that each object will retain the original options given to it? (And here's some example code of what I'm doing in the plugin)
(function($) {
$.fn.myPlugin = function(options) {
// build main options before element iteration
var opts = $.extend({}, $.fn.myPlugin.defaults, options);
_option1 = opts.option1;
_option2 = opts.option2;
_option3 = opts.option3;
// iterate all matched elements
return this.each(function() {
callPluginFunctions( this, opts );
});
};
....code continued....
I realize this is some kind of scope creep or something. So, how do I get my options to stay attached and remain in the scope of the original object (ie #myDiv1) that they were given to.
EDIT: In doing some research I see that you can store data to an object using jQuery's .data function, and the docs say jQuery UI uses it extensively. Would the proper thing to do here be store the options on the object using .data, then when referenced later use the options stored in .data ???

First, you will generally want to handle the command within your extension method. Second, you should be attaching configurations to each item...
(function($){
var defaultOptions = { /* default settings here */ };
//called on the native object directly, wrap with $(obj) if needed.
function initializeObject(obj, options) {
//assign the options to the object instance.
$(obj).data('myPlugin-options', $.extend(defaultOptions, options) );
//do other initialization tasks on the individual item here...
}
function updateObject(obj) {
// use $(obj).data('myPlugin-options');
}
function setOption(obj, key, value) {
var d = $(obj).data('myPlugin-options');
d[key] = value;
$(obj).data('myPlugin-options', d);
}
$.fn.myPlugin = function(command, option, val) {
if (typeof command == "object") {
//initialization
return this.each(function(){
initializeObject(this, command);
});
}
if (typeof command == "string") {
// method or argument query
switch (command.toLowerCase()) {
case 'option':
//get value, return the first item's value
if (typeof val == undefined) return this.eq(0).data('myPlugin-options')[option];
//set option value
return this.each(function() {
setOption(this, option, val);
});
case 'update':
return this.each(function() {
updateObject(this);
});
//other commands here.
}
}
}
})(jQuery)
With the above example, you have a generic template for a jQuery extension, It's usually good form to have the following convention for use..
Initialization:
$(...).myPlugin({ initialization-options-here });
Command:
$(...).myPlugin('command-name'); //where command can be update, etc.
Get Option:
var myValue = $(...).myPlugin('option', 'option-name');
Set Option:
$(...).myPlugin('option', 'option-name', newValue);
Updated to use .data off of each individual obj.

I've been having the same problem, but only functions passed were being overwritten. Straight up properties were persisting.
Anyway, to further explain what ~reinierpost meant, changing your code to this should work. You'll have to pass 'opts' everywhere, but I think that's necessary to take the options out of the plugin-wide namespace.
$.fn.myPlugin = function(options) {
// iterate all matched elements
return this.each(function() {
// build main options before element iteration
var opts = $.extend({}, $.fn.myPlugin.defaults, options);
callPluginFunctions( this, opts );
});
};
Edit: Here's code from my plugin
this.each(function() {
var thisConfig = config;
thisConfig = $.extend(thisConfig,settings);
$.attach($(this),thisConfig);
});
...
$.attach = function($target,config){
So I have no plugin-wide "config" - just inside each function.

Your options are plugin-wide. Move them inside the each().
(Why are you asking this question? You pretty much spell out the solution yourself.)