Javascript object constructor setting as undefined - javascript

I've created a new object, and in that object I have several object variables, but the events (optional) object isn't being set correctly. It's coming up as undefined when called in the build function by the event tab, and my guess it's something to do with it possibly being asynchronous. Below is my object and call, and also what I'm getting when referencing the object.
I can't figure out why exactly it's coming in as undefined as it's being set before the build function is even called.
UPDATE: This fiddle has the exact code as being called. https://jsfiddle.net/trickell/Leg1gqkz/2/
The problem is in the checkEvents() method.
var Wizard = function(id, events) {
this.activeTab = '';
this.prevTab = '';
this.nextTab = '';
this.events = (events) ? events : {}; // Optional events object. User may define events based on tab. (ex. "tabName" : function(){})
console.log(this.events); // Returns object with no keys
this.build(id);
return this;
}
Wizard.prototype.build = function(id){
var tab = id,
events = this.events;
// **** This is what's showing up as undefined!!! *****/
console.log(events.cardInfo);
}
(function($, undefined){
var wiz = new Wizard($('#package_wizard'),
{
cardInfo : function() {
alert('hello world');
}
});
})(jQuery);

The problem is that you're missing a semicolon after your definition for build. Without a semicolon, you're essentially doing this:
Wizard.prototype.build = function() {
// do stuff
}(function($, undefined) { ... })();
Meaning, you're trying to call the function immediately and pass it a function as an argument. Here's your code with semicolons in the right places.
var Wizard = function(id, events) {
console.log(events);
this.activeTab = '';
this.prevTab = '';
this.nextTab = '';
this.events = (events) ? events : {}; // Optional events object. User may define events based on tab. (ex. "tabName" : function(){})
console.log(this.events); // Returns object with no keys
this.build(id);
return this;
}; // <-- Here's a semicolon
Wizard.prototype.build = function(id) {
var tab = id,
events = this.events;
// **** This is what's showing up as undefined!!! *****/
console.log(events.cardInfo);
}; // <-- and the original problem
(function($, undefined) {
var wiz = new Wizard($('#package_wizard'), {
cardInfo: function() {
alert('hello world');
}
});
})(jQuery);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
--
As for your update, the problem is you have a typo. You wrote
event.cardInfo()
when you should have written
events.cardInfo()

Related

jQuery plugin object looses variable?

I'm developing a simple plugin with jQuery. As I see it I need to do it like this:
(function($) {
var somePrivateFn = function() {
alert(this.x);
}
$.fn.myPlugin = function() {
if(typeof arguments[0] === "string") {
var fnargs = Array.prototype.slice(arguments, 1);
// pluginData will be undefined
var pluginData = this.pluginData;
somePrivateFn.apply(pluginData, fnargs);
}
return this.each(function() {
var data = this.pluginData = {};
data.x = 1;
};
}
})(jQuery);
Of course my plugin needs to store some variables for the jquery object it's working on. To do this I just place an additional variable "pluginData" at the jQuery object itself. The problem is it is not accessible later. How to deal with it? What's the best approach to do this?
Pass the object when you run the plugin. $('div').myPlugin(a_data_object) It will persist to within the this.each loop.
This var options=$.extend({}, pluginData); will keep the data in one iteration from passing through to the next.
If you want to manipulate then store that data on the element you would use $.data().
(function($) {
console.clear();
var somePrivateFn = function(data) {
console.log(data.x);
}
$.fn.myPlugin = function(pluginData) {
// send to another func
somePrivateFn(pluginData);
// use on each div
return this.each(function(i) {
var options=$.extend({}, pluginData);
// add some example data
options.y = "i am y";
options.iteration=i;
options.text=$(this).text();
// store it on the element
$(this).data('pluginData', options);
});
}
// run the plugin on div elements
$('div').myPlugin({x:"i am x"});
// check out the data later
$('div').each(function(){
console.log($(this).data('pluginData'));
});
})(jQuery);
Example: http://jsfiddle.net/xXt5W/1/
$.data() docs: https://api.jquery.com/jQuery.data/

Javascript: How do you call a variable function inside a prototype class?

Okay so we have a project ongoing, and it is to be passed today. But I have a problem.
This is the sample code:
output.js
var MapPrintDialog = Class.create();
MapPrintDialog.prototype = {
// 他の画面からテンプレート情報を更新するために呼ばれる。
comboReload : function() {
var val = tempComb.getValue();
tempComb.store.load({
callback: function(result, o) {
if (this.store.data.keys.indexOf(val) == -1) {
this.setValue(this.store.data.keys[0]);
this.fireEvent("select", this);
}
}.createDelegate(tempComb)
});
},
initialize : function(){
this.define();
},
define : function(){
var DrawPrintAreaFrame = function(mode, noUpdateStatusBarText){
var cs = getCurrentSetting();
if (mode == "init" || mode == "edit"){
PrintController.DrawMapPrintArea(cs.center.x, cs.center.y, cs.scale, cs.result.PrintMaps[0].Width, cs.result.PrintMaps[0].Height, cs.result.PageRowCount, cs.result.PageColumnCount, mode);
}
else if (mode == "delete"){
PrintFrameManager.ClearPrintFrame();
}
if (noUpdateStatusBarText) {
gisapp.noUpdateStatusBarText = true;
}
gisapp.refreshMap();
}
}
Now my problem is, how will I call "DrawPrintAreaFrame" from another js file?
I tried:
MapPrintDialog.prototype.define().DrawPrintAreaFrame("edit");
MapPrintDialog.prototype.define.DrawPrintAreaFrame("edit");
MapPrintDialog.define().DrawPrintAreaFrame("edit");
MapPrintDialog.define.DrawPrintAreaFrame("edit");
MapPrintDialog.DrawPrintAreaFrame("edit");
DrawPrintAreaFrame("edit");
but it gives me an error lol. How will I fix this? Please don't be too harsh, I just started learning javascript but they gave me an advanced project which isn't really "beginner" friendly XD
EDIT ----------------------
Okay now i tried to modify it like this:
var MapPrintDialog = Class.create();
MapPrintDialog.prototype = {
// 他の画面からテンプレート情報を更新するために呼ばれる。
comboReload : function() {
var val = tempComb.getValue();
tempComb.store.load({
callback: function(result, o) {
if (this.store.data.keys.indexOf(val) == -1) {
this.setValue(this.store.data.keys[0]);
this.fireEvent("select", this);
}
}.createDelegate(tempComb)
});
},
initialize : function(){
this.DrawPrintAreaFrame("edit");
}
}
function DrawPrintAreaFrame(mode, noUpdateStatusBarText){
var cs = gisapp.getCurrentView();
if (mode == "init" || mode == "edit"){
PrintController.DrawMapPrintArea(cs.center.x, cs.center.y, cs.scale, cs.result.PrintMaps[0].Width, cs.result.PrintMaps[0].Height, cs.result.PageRowCount, cs.result.PageColumnCount, mode);
}
else if (mode == "delete"){
PrintFrameManager.ClearPrintFrame();
}
if (noUpdateStatusBarText) {
gisapp.noUpdateStatusBarText = true;
}
gisapp.refreshMap();
}
But it gives me: Javascript runtime error: Object doesn't support property or method 'DrawPrintAreaFrame'
You have 2 different way:
1- you have to first change it like this:
define : function(){
var DrawPrintAreaFrame = function(mode, noUpdateStatusBarText){
//You function code
}
this.getDrawPrintAreaFrame = function(){
return DrawPrintAreaFrame;
}
}
then create your object using your class:
var obj = new MapPrintDialog();
obj.define();
obj.getDrawPrintAreaFrame().call(obj, "edit");
2- remove the define method and add your function to prototype:
MapPrintDialog.prototype.DrawPrintAreaFrame = function(){
//your function code
}
create your object and simply call your method like this:
var obj = new MapPrintDialog();
obj.DrawPrintAreaFrame("edit");
It's funny, because I said you have 2 ways, and the third one just came up:
3- as far as you use Prototype framework you can use MapPrintDialog.addMethods, which is there to be used to add new instance methods to your class, remove your define and DrawPrintAreaFrame functions and add this:
MapPrintDialog.addMethods({
DrawPrintAreaFrame: function DrawPrintAreaFrame(){
//your code
}
});
or even without removing your method you can use it like:
define : function(){
var DrawPrintAreaFrame = function(mode, noUpdateStatusBarText){
//You function code
}
MapPrintDialog.addMethods({ DrawPrintAreaFrame: DrawPrintAreaFrame });
}
and create your instance and call the method:
var obj = new MapPrintDialog();
obj.DrawPrintAreaFrame("edit");
4- try this if you need your function like a sort of static method, without needing to create a instance:
MapPrintDialog.DrawPrintAreaFrame = function(){
//You function code
}
and call it like this
MapPrintDialog.DrawPrintAreaFrame("edit");
and if you want to define it in runtime, add the whole definition to your define method like this:
define : function(){
MapPrintDialog.DrawPrintAreaFrame = function(){
//You function code
}
}

JavaScript: Not Calling Constructor Function

Can someone shed some light as to why this doesn't work the way I think it should (or what I'm overlooking).
function Pane(data) {
var state = {
show: function(data) {
var pane = document.querySelector('.pane[data-content='+data.target+']');
pane.classList.add('active');
},
hide: function(data) {
var pane = document.querySelector('.pane[data-content='+data.target+']');
var paneSibling = $(pane.parentNode.childNodes);
paneSibling.each(function(sibling) {
if(check.isElement(sibling)) {
var isActive = sibling.classList.contains('active');
if(sibling != pane && isActive) {
sibling.classList.remove('active');
};
};
});
}
}
return state;
}
So I can console log Pane(arg).show/hide and it'll log it as a function, so why is it when I call Pane(arg).show it doesn't do anything? The functions in the object work (outside of the constructor function in their own functions).
The function is returning the state object, so it will never return the constructed object, even when used with new. Since state contains those methods, you can just call the function and immediately invoke one of the methods on the returned object.
Now, if you're expecting show and hide to automatically have access to data via closure, it's not working because you're shadowing the variable by declaring the method parameters. You can do this instead:
function Pane(data) {
var state = {
show: function() {
var data = data || arguments[0];
var pane = document.querySelector('.pane[data-content='+data.target+']');
pane.classList.add('active');
},
hide: function() {
var data = data || arguments[0];
var pane = document.querySelector('.pane[data-content='+data.target+']');
var paneSibling = $(pane.parentNode.childNodes);
paneSibling.each(function(sibling) {
if(check.isElement(sibling)) {
var isActive = sibling.classList.contains('active');
if(sibling != pane && isActive) {
sibling.classList.remove('active');
};
};
});
}
}
return state;
}
Then you can use it like this:
Pane({}).show();
Or like this:
var p = Pane();
p.show();
Or force a new argument when needed:
p.show({foo:'bar'});
You are overriding the original argument in each function.
So what you are doing is to find elements with the attribute data-content='undefined'
This obviously doesn't work.
So to fix this you should just remove the data argument in the show/hide function.
Here is a plnkr showing the problem and fix.

Problem with Event Handling via YUI

When users click "search" input element, the search text inside the input will disappear and since I have several controls like that, I thought I could make the code reusable. Here is my code formerly done and working with jQuery but now in YUI I cannot make it work.
var subscriptionBoxTarget = "div.main div.main-content div.side-right div.subscription-box input";
var ssbNode = YAHOO.util.Selector.query(subscriptionBoxTarget);
var ssbValue = YAHOO.util.DOM.getAttribute(ssbNode,"value");
var subscriptionBox = new RemovableText(ssbNode,ssbValue,null);
subscriptionBox.bind();
////////////////////////////////
//target : the target of the element which dispatches the event
// defaultText : the default for input[type=text] elements
// callBack : is a function which is run after everthing is completed
function RemovableText(target,defaultText,callBack)
{
var target = target; //private members
var defaultText = defaultText;
var callBack = callBack;
//instance method
this.bind = function()
{
mouseClick(target,defaultText);
mouseOff(target,defaultText);
if(callBack != null)
callBack();
}
//private methods
var mouseClick = function(eventTarget,defaultValue)
{
var _eventTarget = eventTarget;
var _defaultValue = defaultValue;
/*$(eventTarget).bind("click",function(){
var currentValue = $(this).val();
if(currentValue == defaultValue)
$(this).val("");
});*/
YAHOO.util.Event.addListener(_eventTarget,"click",function(e){
alert(e);
});
}
var mouseOff = function(eventTarget,defaultValue)
{
var _eventTarget = eventTarget;
var _defaultValue = defaultValue;
/*$(eventTarget).bind("blur",function(){
var currentValue = $(this).val();
if(currentValue == "")
$(this).val(_defaultValue);
});*/
YAHOO.util.Event.addListener(_eventTarget,"blur",function(e){
alert(e);
});
}
}
You have a lot of unnecessary code here.
The input parameters passed to the RemovableText constructor are available by closure to all the methods defined inside. You don't need to, and shouldn't redefine named params as vars.
function RemovableText(target, defaultText, callback) {
this.bind = function () {
YAHOO.util.Event.on(target, 'click', function (e) {
/* You can reference target, defaultText, and callback in here as well */
});
YAHOO.util.Event.on(target, 'blur', function (e) { /* and here */ });
if (callback) {
callback();
}
};
}
The definition of an instance method from within the constructor seems dubious, as is the requirement that the values passed to the constructor must be kept private. Just assign them to instance properties (this._target = target; etc) and add instance methods to the prototype. If the functionality you're after is just this simple, then why bother with methods at all?
Using the click event does not support keyboard navigation. You should use the focus event.
I'm not sure why you would have a callback passed at construction that fires immediately after attaching the event subscribers.

How to create a jQuery plugin with methods?

I'm trying to write a jQuery plugin that will provide additional functions/methods to the object that calls it. All the tutorials I read online (have been browsing for the past 2 hours) include, at the most, how to add options, but not additional functions.
Here's what I am looking to do:
//format div to be a message container by calling the plugin for that div
$("#mydiv").messagePlugin();
$("#mydiv").messagePlugin().saySomething("hello");
or something along those lines.
Here's what it boils down to: I call the plugin, then I call a function associated with that plugin. I can't seem to find a way to do this, and I've seen many plugins do it before.
Here's what I have so far for the plugin:
jQuery.fn.messagePlugin = function() {
return this.each(function(){
alert(this);
});
//i tried to do this, but it does not seem to work
jQuery.fn.messagePlugin.saySomething = function(message){
$(this).html(message);
}
};
How can I achieve something like that?
Thank you!
Update Nov 18, 2013: I've changed the correct answer to that of Hari's following comments and upvotes.
According to the jQuery Plugin Authoring page (http://docs.jquery.com/Plugins/Authoring), it's best not to muddy up the jQuery and jQuery.fn namespaces. They suggest this method:
(function( $ ){
var methods = {
init : function(options) {
},
show : function( ) { },// IS
hide : function( ) { },// GOOD
update : function( content ) { }// !!!
};
$.fn.tooltip = function(methodOrOptions) {
if ( methods[methodOrOptions] ) {
return methods[ methodOrOptions ].apply( this, Array.prototype.slice.call( arguments, 1 ));
} else if ( typeof methodOrOptions === 'object' || ! methodOrOptions ) {
// Default to "init"
return methods.init.apply( this, arguments );
} else {
$.error( 'Method ' + methodOrOptions + ' does not exist on jQuery.tooltip' );
}
};
})( jQuery );
Basically you store your functions in an array (scoped to the wrapping function) and check for an entry if the parameter passed is a string, reverting to a default method ("init" here) if the parameter is an object (or null).
Then you can call the methods like so...
$('div').tooltip(); // calls the init method
$('div').tooltip({ // calls the init method
foo : 'bar'
});
$('div').tooltip('hide'); // calls the hide method
$('div').tooltip('update', 'This is the new tooltip content!'); // calls the update method
Javascripts "arguments" variable is an array of all the arguments passed so it works with arbitrary lengths of function parameters.
Here's the pattern I have used for creating plugins with additional methods. You would use it like:
$('selector').myplugin( { key: 'value' } );
or, to invoke a method directly,
$('selector').myplugin( 'mymethod1', 'argument' );
Example:
;(function($) {
$.fn.extend({
myplugin: function(options,arg) {
if (options && typeof(options) == 'object') {
options = $.extend( {}, $.myplugin.defaults, options );
}
// this creates a plugin for each element in
// the selector or runs the function once per
// selector. To have it do so for just the
// first element (once), return false after
// creating the plugin to stop the each iteration
this.each(function() {
new $.myplugin(this, options, arg );
});
return;
}
});
$.myplugin = function( elem, options, arg ) {
if (options && typeof(options) == 'string') {
if (options == 'mymethod1') {
myplugin_method1( arg );
}
else if (options == 'mymethod2') {
myplugin_method2( arg );
}
return;
}
...normal plugin actions...
function myplugin_method1(arg)
{
...do method1 with this and arg
}
function myplugin_method2(arg)
{
...do method2 with this and arg
}
};
$.myplugin.defaults = {
...
};
})(jQuery);
What about this approach:
jQuery.fn.messagePlugin = function(){
var selectedObjects = this;
return {
saySomething : function(message){
$(selectedObjects).each(function(){
$(this).html(message);
});
return selectedObjects; // Preserve the jQuery chainability
},
anotherAction : function(){
//...
return selectedObjects;
}
};
}
// Usage:
$('p').messagePlugin().saySomething('I am a Paragraph').css('color', 'red');
The selected objects are stored in the messagePlugin closure, and that function returns an object that contains the functions associated with the plugin, the in each function you can perform the desired actions to the currently selected objects.
You can test and play with the code here.
Edit: Updated code to preserve the power of the jQuery chainability.
The problem with the currently selected answer is that you're not actually creating a new instance of the custom plugin for every element in the selector like you think you're doing... you're actually only creating a single instance and passing in the selector itself as the scope.
View this fiddle for a deeper explanation.
Instead, you'll need to loop through the selector using jQuery.each and instantiate a new instance of the custom plugin for every element in the selector.
Here's how:
(function($) {
var CustomPlugin = function($el, options) {
this._defaults = {
randomizer: Math.random()
};
this._options = $.extend(true, {}, this._defaults, options);
this.options = function(options) {
return (options) ?
$.extend(true, this._options, options) :
this._options;
};
this.move = function() {
$el.css('margin-left', this._options.randomizer * 100);
};
};
$.fn.customPlugin = function(methodOrOptions) {
var method = (typeof methodOrOptions === 'string') ? methodOrOptions : undefined;
if (method) {
var customPlugins = [];
function getCustomPlugin() {
var $el = $(this);
var customPlugin = $el.data('customPlugin');
customPlugins.push(customPlugin);
}
this.each(getCustomPlugin);
var args = (arguments.length > 1) ? Array.prototype.slice.call(arguments, 1) : undefined;
var results = [];
function applyMethod(index) {
var customPlugin = customPlugins[index];
if (!customPlugin) {
console.warn('$.customPlugin not instantiated yet');
console.info(this);
results.push(undefined);
return;
}
if (typeof customPlugin[method] === 'function') {
var result = customPlugin[method].apply(customPlugin, args);
results.push(result);
} else {
console.warn('Method \'' + method + '\' not defined in $.customPlugin');
}
}
this.each(applyMethod);
return (results.length > 1) ? results : results[0];
} else {
var options = (typeof methodOrOptions === 'object') ? methodOrOptions : undefined;
function init() {
var $el = $(this);
var customPlugin = new CustomPlugin($el, options);
$el.data('customPlugin', customPlugin);
}
return this.each(init);
}
};
})(jQuery);
And a working fiddle.
You'll notice how in the first fiddle, all divs are always moved to the right the exact same number of pixels. That is because only one options object exists for all elements in the selector.
Using the technique written above, you'll notice that in the second fiddle, each div is not aligned and is randomly moved (excluding the first div as it's randomizer is always set to 1 on line 89). That is because we are now properly instantiating a new custom plugin instance for every element in the selector. Every element has its own options object and is not saved in the selector, but in the instance of the custom plugin itself.
This means that you'll be able to access the methods of the custom plugin instantiated on a specific element in the DOM from new jQuery selectors and aren't forced to cache them, as you would be in the first fiddle.
For example, this would return an array of all options objects using the technique in the second fiddle. It would return undefined in the first.
$('div').customPlugin();
$('div').customPlugin('options'); // would return an array of all options objects
This is how you would have to access the options object in the first fiddle, and would only return a single object, not an array of them:
var divs = $('div').customPlugin();
divs.customPlugin('options'); // would return a single options object
$('div').customPlugin('options');
// would return undefined, since it's not a cached selector
I'd suggest using the technique above, not the one from the currently selected answer.
Use the jQuery UI Widget Factory.
Writing Stateful Plugins with the jQuery UI Widget Factory
How To Use the Widget Factory
Example:
$.widget( "myNamespace.myPlugin", {
options: {
// Default options
},
_create: function() {
// Initialization logic here
},
// Create a public method.
myPublicMethod: function( argument ) {
// ...
},
// Create a private method.
_myPrivateMethod: function( argument ) {
// ...
}
});
Initialization:
$('#my-element').myPlugin();
$('#my-element').myPlugin( {defaultValue:10} );
Method calling:
$('#my-element').myPlugin('myPublicMethod', 20);
(This is how the jQuery UI library is built.)
A simpler approach is to use nested functions. Then you can chain them in an object-oriented fashion. Example:
jQuery.fn.MyPlugin = function()
{
var _this = this;
var a = 1;
jQuery.fn.MyPlugin.DoSomething = function()
{
var b = a;
var c = 2;
jQuery.fn.MyPlugin.DoSomething.DoEvenMore = function()
{
var d = a;
var e = c;
var f = 3;
return _this;
};
return _this;
};
return this;
};
And here's how to call it:
var pluginContainer = $("#divSomeContainer");
pluginContainer.MyPlugin();
pluginContainer.MyPlugin.DoSomething();
pluginContainer.MyPlugin.DoSomething.DoEvenMore();
Be careful though. You cannot call a nested function until it has been created. So you cannot do this:
var pluginContainer = $("#divSomeContainer");
pluginContainer.MyPlugin();
pluginContainer.MyPlugin.DoSomething.DoEvenMore();
pluginContainer.MyPlugin.DoSomething();
The DoEvenMore function doesn't even exist because the DoSomething function hasn't been run yet which is required to create the DoEvenMore function. For most jQuery plugins, you really are only going to have one level of nested functions and not two as I've shown here.
Just make sure that when you create nested functions that you define these functions at the beginning of their parent function before any other code in the parent function gets executed.
Finally, note that the "this" member is stored in a variable called "_this". For nested functions, you should return "_this" if you need a reference to the instance in the calling client. You cannot just return "this" in the nested function because that will return a reference to the function and not the jQuery instance. Returning a jQuery reference allows you to chain intrinsic jQuery methods on return.
I got it from jQuery Plugin Boilerplate
Also described in jQuery Plugin Boilerplate, reprise
// jQuery Plugin Boilerplate
// A boilerplate for jumpstarting jQuery plugins development
// version 1.1, May 14th, 2011
// by Stefan Gabos
// remember to change every instance of "pluginName" to the name of your plugin!
(function($) {
// here we go!
$.pluginName = function(element, options) {
// plugin's default options
// this is private property and is accessible only from inside the plugin
var defaults = {
foo: 'bar',
// if your plugin is event-driven, you may provide callback capabilities
// for its events. execute these functions before or after events of your
// plugin, so that users may customize those particular events without
// changing the plugin's code
onFoo: function() {}
}
// to avoid confusions, use "plugin" to reference the
// current instance of the object
var plugin = this;
// this will hold the merged default, and user-provided options
// plugin's properties will be available through this object like:
// plugin.settings.propertyName from inside the plugin or
// element.data('pluginName').settings.propertyName from outside the plugin,
// where "element" is the element the plugin is attached to;
plugin.settings = {}
var $element = $(element), // reference to the jQuery version of DOM element
element = element; // reference to the actual DOM element
// the "constructor" method that gets called when the object is created
plugin.init = function() {
// the plugin's final properties are the merged default and
// user-provided options (if any)
plugin.settings = $.extend({}, defaults, options);
// code goes here
}
// public methods
// these methods can be called like:
// plugin.methodName(arg1, arg2, ... argn) from inside the plugin or
// element.data('pluginName').publicMethod(arg1, arg2, ... argn) from outside
// the plugin, where "element" is the element the plugin is attached to;
// a public method. for demonstration purposes only - remove it!
plugin.foo_public_method = function() {
// code goes here
}
// private methods
// these methods can be called only from inside the plugin like:
// methodName(arg1, arg2, ... argn)
// a private method. for demonstration purposes only - remove it!
var foo_private_method = function() {
// code goes here
}
// fire up the plugin!
// call the "constructor" method
plugin.init();
}
// add the plugin to the jQuery.fn object
$.fn.pluginName = function(options) {
// iterate through the DOM elements we are attaching the plugin to
return this.each(function() {
// if plugin has not already been attached to the element
if (undefined == $(this).data('pluginName')) {
// create a new instance of the plugin
// pass the DOM element and the user-provided options as arguments
var plugin = new $.pluginName(this, options);
// in the jQuery version of the element
// store a reference to the plugin object
// you can later access the plugin and its methods and properties like
// element.data('pluginName').publicMethod(arg1, arg2, ... argn) or
// element.data('pluginName').settings.propertyName
$(this).data('pluginName', plugin);
}
});
}
})(jQuery);
Too late but maybe it can help someone one day.
I was in the same situation like, creating a jQuery plugin with some methods, and after reading some articles and some tires I create a jQuery plugin boilerplate (https://github.com/acanimal/jQuery-Plugin-Boilerplate).
In addition, I develop with it a plugin to manage tags (https://github.com/acanimal/tagger.js) and wrote a two blog posts explaining step by step the creation of a jQuery plugin (https://www.acuriousanimal.com/blog/20130115/things-i-learned-creating-a-jquery-plugin-part-i).
You can do:
(function($) {
var YourPlugin = function(element, option) {
var defaults = {
//default value
}
this.option = $.extend({}, defaults, option);
this.$element = $(element);
this.init();
}
YourPlugin.prototype = {
init: function() { },
show: function() { },
//another functions
}
$.fn.yourPlugin = function(option) {
var arg = arguments,
options = typeof option == 'object' && option;;
return this.each(function() {
var $this = $(this),
data = $this.data('yourPlugin');
if (!data) $this.data('yourPlugin', (data = new YourPlugin(this, options)));
if (typeof option === 'string') {
if (arg.length > 1) {
data[option].apply(data, Array.prototype.slice.call(arg, 1));
} else {
data[option]();
}
}
});
};
});
In this way your plugins object is stored as data value in your element.
//Initialization without option
$('#myId').yourPlugin();
//Initialization with option
$('#myId').yourPlugin({
// your option
});
// call show method
$('#myId').yourPlugin('show');
What about using triggers? Does anyone know any drawback using them?
The benefit is that all internal variables are accessible via the triggers, and the code is very simple.
See on jsfiddle.
Example usage
<div id="mydiv">This is the message container...</div>
<script>
var mp = $("#mydiv").messagePlugin();
// the plugin returns the element it is called on
mp.trigger("messagePlugin.saySomething", "hello");
// so defining the mp variable is not needed...
$("#mydiv").trigger("messagePlugin.repeatLastMessage");
</script>
Plugin
jQuery.fn.messagePlugin = function() {
return this.each(function() {
var lastmessage,
$this = $(this);
$this.on('messagePlugin.saySomething', function(e, message) {
lastmessage = message;
saySomething(message);
});
$this.on('messagePlugin.repeatLastMessage', function(e) {
repeatLastMessage();
});
function saySomething(message) {
$this.html("<p>" + message + "</p>");
}
function repeatLastMessage() {
$this.append('<p>Last message was: ' + lastmessage + '</p>');
}
});
}
Here I want to suggest steps to create simple plugin with arguments.
(function($) {
$.fn.myFirstPlugin = function(options) {
// Default params
var params = $.extend({
text : 'Default Title',
fontsize : 10,
}, options);
return $(this).text(params.text);
}
}(jQuery));
$('.cls-title').myFirstPlugin({ text : 'Argument Title' });
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<h1 class="cls-title"></h1>
Here, we have added default object called params and set default values of options using extend function. Hence, If we pass blank argument then it will set default values instead otherwise it will set.
Read more: How to Create JQuery plugin
Try this one:
$.fn.extend({
"calendar":function(){
console.log(this);
var methods = {
"add":function(){console.log("add"); return this;},
"init":function(){console.log("init"); return this;},
"sample":function(){console.log("sample"); return this;}
};
methods.init(); // you can call any method inside
return methods;
}});
$.fn.calendar() // caller or
$.fn.calendar().sample().add().sample() ......; // call methods
Here is my bare-bones version of this. Similar to the ones posted before, you would call like:
$('#myDiv').MessagePlugin({ yourSettings: 'here' })
.MessagePlugin('saySomething','Hello World!');
-or access the instance directly # plugin_MessagePlugin
$elem = $('#myDiv').MessagePlugin();
var instance = $elem.data('plugin_MessagePlugin');
instance.saySomething('Hello World!');
MessagePlugin.js
;(function($){
function MessagePlugin(element,settings){ // The Plugin
this.$elem = element;
this._settings = settings;
this.settings = $.extend(this._default,settings);
}
MessagePlugin.prototype = { // The Plugin prototype
_default: {
message: 'Generic message'
},
initialize: function(){},
saySomething: function(message){
message = message || this._default.message;
return this.$elem.html(message);
}
};
$.fn.MessagePlugin = function(settings){ // The Plugin call
var instance = this.data('plugin_MessagePlugin'); // Get instance
if(instance===undefined){ // Do instantiate if undefined
settings = settings || {};
this.data('plugin_MessagePlugin',new MessagePlugin(this,settings));
return this;
}
if($.isFunction(MessagePlugin.prototype[settings])){ // Call method if argument is name of method
var args = Array.prototype.slice.call(arguments); // Get the arguments as Array
args.shift(); // Remove first argument (name of method)
return MessagePlugin.prototype[settings].apply(instance, args); // Call the method
}
// Do error handling
return this;
}
})(jQuery);
The following plugin-structure utilizes the jQuery-data()-method to provide a public interface to internal plugin-methods/-settings (while preserving jQuery-chainability):
(function($, window, undefined) {
const defaults = {
elementId : null,
shape : "square",
color : "aqua",
borderWidth : "10px",
borderColor : "DarkGray"
};
$.fn.myPlugin = function(options) {
// settings, e.g.:
var settings = $.extend({}, defaults, options);
// private methods, e.g.:
var setBorder = function(color, width) {
settings.borderColor = color;
settings.borderWidth = width;
drawShape();
};
var drawShape = function() {
$('#' + settings.elementId).attr('class', settings.shape + " " + "center");
$('#' + settings.elementId).css({
'background-color': settings.color,
'border': settings.borderWidth + ' solid ' + settings.borderColor
});
$('#' + settings.elementId).html(settings.color + " " + settings.shape);
};
return this.each(function() { // jQuery chainability
// set stuff on ini, e.g.:
settings.elementId = $(this).attr('id');
drawShape();
// PUBLIC INTERFACE
// gives us stuff like:
//
// $("#...").data('myPlugin').myPublicPluginMethod();
//
var myPlugin = {
element: $(this),
// access private plugin methods, e.g.:
setBorder: function(color, width) {
setBorder(color, width);
return this.element; // To ensure jQuery chainability
},
// access plugin settings, e.g.:
color: function() {
return settings.color;
},
// access setting "shape"
shape: function() {
return settings.shape;
},
// inspect settings
inspectSettings: function() {
msg = "inspecting settings for element '" + settings.elementId + "':";
msg += "\n--- shape: '" + settings.shape + "'";
msg += "\n--- color: '" + settings.color + "'";
msg += "\n--- border: '" + settings.borderWidth + ' solid ' + settings.borderColor + "'";
return msg;
},
// do stuff on element, e.g.:
change: function(shape, color) {
settings.shape = shape;
settings.color = color;
drawShape();
return this.element; // To ensure jQuery chainability
}
};
$(this).data("myPlugin", myPlugin);
}); // return this.each
}; // myPlugin
}(jQuery));
Now you can call internal plugin-methods to access or modify plugin data or the relevant element using this syntax:
$("#...").data('myPlugin').myPublicPluginMethod();
As long as you return the current element (this) from inside your implementation of myPublicPluginMethod() jQuery-chainability
will be preserved - so the following works:
$("#...").data('myPlugin').myPublicPluginMethod().css("color", "red").html("....");
Here are some examples (for details checkout this fiddle):
// initialize plugin on elements, e.g.:
$("#shape1").myPlugin({shape: 'square', color: 'blue', borderColor: 'SteelBlue'});
$("#shape2").myPlugin({shape: 'rectangle', color: 'red', borderColor: '#ff4d4d'});
$("#shape3").myPlugin({shape: 'circle', color: 'green', borderColor: 'LimeGreen'});
// calling plugin methods to read element specific plugin settings:
console.log($("#shape1").data('myPlugin').inspectSettings());
console.log($("#shape2").data('myPlugin').inspectSettings());
console.log($("#shape3").data('myPlugin').inspectSettings());
// calling plugin methods to modify elements, e.g.:
// (OMG! And they are chainable too!)
$("#shape1").data('myPlugin').change("circle", "green").fadeOut(2000).fadeIn(2000);
$("#shape1").data('myPlugin').setBorder('LimeGreen', '30px');
$("#shape2").data('myPlugin').change("rectangle", "red");
$("#shape2").data('myPlugin').setBorder('#ff4d4d', '40px').css({
'width': '350px',
'font-size': '2em'
}).slideUp(2000).slideDown(2000);
$("#shape3").data('myPlugin').change("square", "blue").fadeOut(2000).fadeIn(2000);
$("#shape3").data('myPlugin').setBorder('SteelBlue', '30px');
// etc. ...
This can actually be made to work in a "nice" way using defineProperty. Where "nice" means without having to use () to get plugin namespace nor having to pass function name by string.
Compatibility nit: defineProperty doesn't work in ancient browsers such as IE8 and below.
Caveat: $.fn.color.blue.apply(foo, args) won't work, you need to use foo.color.blue.apply(foo, args).
function $_color(color)
{
return this.css('color', color);
}
function $_color_blue()
{
return this.css('color', 'blue');
}
Object.defineProperty($.fn, 'color',
{
enumerable: true,
get: function()
{
var self = this;
var ret = function() { return $_color.apply(self, arguments); }
ret.blue = function() { return $_color_blue.apply(self, arguments); }
return ret;
}
});
$('#foo').color('#f00');
$('#bar').color.blue();
JSFiddle link
According to jquery standard you can create plugin as follow:
(function($) {
//methods starts here....
var methods = {
init : function(method,options) {
this.loadKeywords.settings = $.extend({}, this.loadKeywords.defaults, options);
methods[method].apply( this, Array.prototype.slice.call( arguments, 1 ));
$loadkeywordbase=$(this);
},
show : function() {
//your code here.................
},
getData : function() {
//your code here.................
}
} // do not put semi colon here otherwise it will not work in ie7
//end of methods
//main plugin function starts here...
$.fn.loadKeywords = function(options,method) {
if (methods[method]) {
return methods[method].apply(this, Array.prototype.slice.call(
arguments, 1));
} else if (typeof method === 'object' || !method) {
return methods.init.apply(this, arguments);
} else {
$.error('Method ' + method + ' does not ecw-Keywords');
}
};
$.fn.loadKeywords.defaults = {
keyName: 'Messages',
Options: '1',
callback: '',
};
$.fn.loadKeywords.settings = {};
//end of plugin keyword function.
})(jQuery);
How to call this plugin?
1.$('your element').loadKeywords('show',{'callback':callbackdata,'keyName':'myKey'}); // show() will be called
Reference: link
I think this might help you...
(function ( $ ) {
$.fn.highlight = function( options ) {
// This is the easiest way to have default options.
var settings = $.extend({
// These are the defaults.
color: "#000",
backgroundColor: "yellow"
}, options );
// Highlight the collection based on the settings variable.
return this.css({
color: settings.color,
backgroundColor: settings.backgroundColor
});
};
}( jQuery ));
In the above example i had created a simple jquery highlight plugin.I had shared an article in which i had discussed about How to Create Your Own jQuery Plugin from Basic to Advance.
I think you should check it out... http://mycodingtricks.com/jquery/how-to-create-your-own-jquery-plugin/
Following is a small plug-in to have warning method for debugging purpose. Keep this code in jquery.debug.js file:
JS:
jQuery.fn.warning = function() {
return this.each(function() {
alert('Tag Name:"' + $(this).prop("tagName") + '".');
});
};
HTML:
<html>
<head>
<title>The jQuery Example</title>
<script type = "text/javascript"
src = "http://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<script src = "jquery.debug.js" type = "text/javascript"></script>
<script type = "text/javascript" language = "javascript">
$(document).ready(function() {
$("div").warning();
$("p").warning();
});
</script>
</head>
<body>
<p>This is paragraph</p>
<div>This is division</div>
</body>
</html>
Here is how I do it:
(function ( $ ) {
$.fn.gridview = function( options ) {
..........
..........
var factory = new htmlFactory();
factory.header(...);
........
};
}( jQuery ));
var htmlFactory = function(){
//header
this.header = function(object){
console.log(object);
}
}
What you did is basically extending jQuery.fn.messagePlugin object by new method. Which is useful but not in your case.
You have to do is using this technique
function methodA(args){ this // refers to object... }
function saySomething(message){ this.html(message); to first function }
jQuery.fn.messagePlugin = function(opts) {
if(opts=='methodA') methodA.call(this);
if(opts=='saySomething') saySomething.call(this, arguments[0]); // arguments is an array of passed parameters
return this.each(function(){
alert(this);
});
};
But you can accomplish what you want I mean there is a way to do $("#mydiv").messagePlugin().saySomething("hello"); My friend he started writing about lugins and how to extend them with your chainf of functionalities here is the link to his blog

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