StructureJS
0.15.2A class based utility library for building modular and scalable web platform applications. Features opt-in classes and utilities which provide a solid foundation and toolset to build your next project.
The DOMElement class is the base view class for all objects that can be placed into the HTML DOM.
$element
JQuery
public
A cached reference to the jQuery DOM element
Default: null
_isReference
Boolean
protected
If a jQuery object was passed into the constructor this will be set as true and this class will not try to add the view to the DOM since it already exists.
_listeners
Any
protected
Holds a reference to added listeners.
_params
Any
protected
Holds onto the value passed into the constructor.
Default: null
_type
String
protected
Holds onto the value passed into the constructor.
Default: null
alpha
Number
public
Indicates the alpha transparency value of the object specified.
checkCount
Number
public
Tracks number of times an element's width has been checked in order to determine if the element has been added to the DOM.
children
Array.A reference to the child DisplayObject instances to this parent object instance.
ctx
CanvasRenderingContext2D
public
The CanvasRenderingContext2D interface provides the 2D rendering context for the drawing surface of a canvas element. This property is only used with the canvas specific display objects.
element
HTMLElement
public
A cached reference to the DOM Element
Default: null
height
Number
public
Indicates the height of the display object, in pixels.
Default: 0
isCreated
Boolean
public
The isCreated property is used to keep track if it is the first time this DisplayObject is created.
Default: false
isEnabled
Boolean
public
The isEnabled property is used to keep track of the enabled state of the object.
Default: false
mouseChildren
Boolean
public
Determines whether or not the children of the object are mouse enabled.
mouseEnabled
Boolean
public
Specifies whether this object receives mouse
name
String
public
Indicates the instance name of the DisplayObject.
numChildren
Int
public
Returns the number of children of this object.
Default: 0
parent
Any
public
Indicates the object that contains a child object. Uses the parent property to specify a relative path to display objects that are above the current display object in the display list hierarchy and helps facilitate event bubbling.
rotation
Number
public
Indicates the rotation of the DisplayObject instance, in degrees, from its original orientation.
scaleX
Number
public
Indicates the horizontal scale (percentage) of the object as applied from the registration point.
scaleY
Number
public
Indicates the vertical scale (percentage) of an object as applied from the registration point of the object.
sjsId
Int
public
The sjsId (StructureJS ID) is a unique identifier automatically assigned to most StructureJS objects upon instantiation.
Default: null
stage
Any
public
The Stage of the display object.
unscaledHeight
Number
public
A property providing access to the unscaledHeight.
Default: 100
unscaledWidth
Number
public
A property providing access to the unscaledWidth.
Default: 100
useHandCursor
Boolean
public
A Boolean value that indicates whether the pointing hand (hand cursor) appears when the pointer rolls over a display object.
visible
Boolean
public
Whether or not the display object is visible.
width
Number
public
Indicates the width of the display object, in pixels.
Default: 0
x
Number
public
A property providing access to the x position.
Default: 0
y
Number
public
A property providing access to the y position.
Default: 0
DOMElement
type
params
// Example: Using DOMElement without extending it.
let aLink = new DOMElement('a', {text: 'Google', href: 'http://www.google.com', 'class': 'externalLink'});
this.addChild(aLink);
// Example: A view passing in a jQuery object.
let view = new CustomView($('.selector'));
this.addChild(view);
// Example: A view extending DOMElement while passing in a jQuery object.
class ClassName extends DOMElement {
constructor($element) {
super($element);
}
create() {
super.create();
// Create and add your child objects to this parent class.
}
enable() {
if (this.isEnabled === true) { return; }
// Enable the child objects and add any event listeners.
super.enable();
}
disable() {
if (this.isEnabled === false) { return; }
// Disable the child objects and remove any event listeners.
super.disable();
}
layout() {
// Layout or update the child objects in this parent class.
}
destroy() {
this.disable();
// Destroy the child objects and references in this parent class to prevent memory leaks.
super.destroy();
}
}
// Example: A view extending DOMElement with a precompiled JavaScript template reference passed in.
class ClassName extends DOMElement {
constructor() {
_super();
}
create() {
super.create('templates/home/homeTemplate', {data: 'some data'});
// Create and add your child objects to this parent class.
}
enable() {
if (this.isEnabled === true) { return; }
// Enable the child objects and add any event listeners.
super.enable();
}
disable() {
if (this.isEnabled === false) { return; }
// Disable the child objects and remove any event listeners.
super.disable();
}
layout() {
// Layout or update the child objects in this parent class.
}
destroy() {
this.disable();
// Destroy the child objects and references in this parent class to prepare for garbage collection.
super.destroy();
}
}
_addClientSideId
child
Adds the sjsId to the DOM element so we can know what what Class object the HTMLElement belongs too.
child
DOMElement
The DOMElement instance to add the sjsId too.
_onAddedToDom
()
protected
Called when the child object is added to the DOM. The method will call DOMElement/layout:method and dispatch the BaseEvent.ADDED_TO_STAGE event.
_removeClientSideId
child
Removes the sjsId and class type from the HTMLElement.
child
DOMElement
The DOMElement instance to add the sjsId too.
addChild
child
child
DOMElement
The DOMElement instance to add as a child of this object instance.
Returns an instance of itself.
this.addChild(domElementInstance);
addChildAt
child
index
Adds a child DisplayObject instance to this DisplayObjectContainerContainer instance. The child is added at the index position specified. An index of 0 represents the back (bottom) of the display list for this DisplayObjectContainerContainer object.
child
DisplayObject
The DisplayObject instance to add as a child of this object instance.
index
Int
The index position to which the child is added. If you specify a currently occupied index position, the child object that exists at that position and all higher positions are moved up one position in the child list.
Returns an instance of itself.
addEventListener
type
callback
scope
[priority=0]
Registers an event listener object with an EventDispatcher object so the listener receives notification of an event.
type
String
The type of event.
callback
Function
The listener function that processes the event. This function must accept an Event object as its only parameter and must return nothing, as this example shows. @example function(event:Event):void
scope
Any
Binds the scope to a particular object (scope is basically what "this" refers to in your function). This can be very useful in JavaScript because scope isn't generally maintained.
[priority=0]
Int
optional
Influences the order in which the listeners are called. Listeners with lower priorities are called after ones with higher priorities.
this.addEventListener(BaseEvent.CHANGE, this._handlerMethod, this);
_handlerMethod(event) {
console.log(event.target + " sent the event.");
console.log(event.type, event.data);
}
addEventListenerOnce
type
callback
scope
[priority=0]
Registers an event listener object once with an EventDispatcher object so the listener will receive the notification of an event.
type
String
The type of event.
callback
Function
The listener function that processes the event. This function must accept an Event object as its only parameter and must return nothing, as this example shows. @example function(event:Event):void
scope
Any
Binds the scope to a particular object (scope is basically what "this" refers to in your function). This can be very useful in JavaScript because scope isn't generally maintained.
[priority=0]
Int
optional
Influences the order in which the listeners are called. Listeners with lower priorities are called after ones with higher priorities.
this.addEventListenerOnce(BaseEvent.CHANGE, this._handlerMethod, this);
_handlerMethod(event) {
console.log(event.target + " sent the event.");
console.log(event.type, event.data);
}
appendTo
type
[enabled=true]
Only use this once per application and use used on your main application Class. This selects HTML element that you want the application to have control over. This method starts the lifecycle of the application.
type
Any
A string value where your application will be appended. This can be an element id (#some-id), element class (.some-class) or a element tag (body).
[enabled=true]
Boolean
optional
Sets the enabled state of the object.
Instantiation Example
This example illustrates how to instantiate your main application or root class.
const app = new MainClass();
app.appendTo('body');
contains
child
Determines whether the specified display object is a child of the DisplayObject instance or the instance itself. The search includes the entire display list including this DisplayObject instance.
child
DisplayObject
The child object to test.
true if the child object is a child of the DisplayObject or the container itself; otherwise false.
create
type
params
The create function is intended to provide a consistent place for the creation and adding of children to the view. It will automatically be called the first time that the view is added to another DisplayObjectContainer. It is critical that all subclasses call the super for this function in their overridden methods.
This method gets called once when the child view is added to another view. If the child view is removed and added to another view the create method will not be called again.
Returns an instance of itself.
// EXAMPLE 1: By default your view class will be a div element:
create() {
super.create();
this._childInstance = new DOMElement();
this.addChild(this._childInstance);
}
// EXAMPLE 2: But lets say you wanted the view to be a ul element:
create() {
super.create('ul');
}
// Then you could nest other elements inside this base view/element.
create() {
super.create('ul', {id: 'myId', 'class': 'myClass anotherClass'});
let li = new DOMElement('li', {text: 'Robert is cool'});
this.addChild(li);
}
// EXAMPLE 3: So that's cool but what if you wanted a block of html to be your view. Let's say you had the below
// inline Handlebar template in your html file.
<script id="todoTemplate" type="text/template">
<div id="htmlTemplate" class="js-todo">
<div id="input-wrapper">
<input type="text" class="list-input" placeholder="{{ data.text }}">
<input type="button" class="list-item-submit" value="Add">
</div>
</div>
</script>
// You would just pass in the id or class selector of the template which in this case is "#todoTemplate".
// There is a second optional argument where you can pass data for the Handlebar template to use.
create() {
super.create('#todoTemplate', { data: this.viewData });
}
// EXAMPLE 4: Or maybe you're using grunt-contrib-handlebars, or similar, to precompile hbs templates
create() {
super.create('templates/HomeTemplate', {data: "some data"});
}
createComponents
componentList
A way to instantiate view classes by found html selectors.
Example: It will find all children elements of the $element property with the 'js-shareEmail' selector. If any selectors are found the EmailShareComponent class will be instantiated and pass the found jQuery element into the contructor.
componentList
Selector: string; component: DOMElement
(Array.<>
Returns all the items created from this createComponents method.
create() {
super.create();
this.createComponents([
{selector: '.js-shareEmail', component: EmailShareComponent},
{selector: '.js-pagination', component: PaginationComponent},
{selector: '.js-carousel', component: CarouselComponent}
]);
}
destroy
()
Void
public
The purpose of the destroy method is to make an object ready for garbage collection. This should be thought of as a one way function. Once destroy is called no further methods should be called on the object or properties accessed. It is the responsibility of those who implement this function to stop all running Timers, all running Sounds, and take any other steps necessary to make an object eligible for garbage collection.
By default the destroy method will null out all properties of the class automatically. You should call destroy on other objects before calling the super.
destroy() {
this.disable();
this._childInstance.destroy();
super.destroy();
}
disable
()
public
chainable
The disable method is responsible for disabling event listeners and/or children of the containing objects.
disable() {
if (this.isEnabled === false) { return; }
this._childInstance.removeEventListener(BaseEvent.CHANGE, this.handlerMethod, this);
this._childInstance.disable();
super.disable();
}
dispatchEvent
event
[data=null]
Dispatches an event into the event flow. The event target is the EventDispatcher object upon which the dispatchEvent() method is called.
event
String | BaseEvent
The Event object or event type string you want to dispatch. You can create custom events, the only requirement is all events must extend BaseEvent.
[data=null]
Any
optional
The optional data you want to send with the event. Do not use this parameter if you are passing in a BaseEvent.
this.dispatchEvent('change');
// Example: Sending data with the event:
this.dispatchEvent('change', {some: 'data'});
// Example: With an event object
// (event type, bubbling set to true, cancelable set to true and passing data) :
let event = new BaseEvent(BaseEvent.CHANGE, true, true, {some: 'data'});
this.dispatchEvent(event);
// Here is a common inline event object being dispatched:
this.dispatchEvent(new BaseEvent(BaseEvent.CHANGE));
enable
()
public
chainable
The enable method is responsible for enabling event listeners and/or children of the containing objects.
enable() {
if (this.isEnabled === true) { return; }
this._childInstance.addEventListener(BaseEvent.CHANGE, this.handlerMethod, this);
this._childInstance.enable();
super.enable();
}
getChild
selector
Returns a DOMElement object with the first found DOM element by the passed in selector.
selector
String
DOM id name, DOM class name or a DOM tag name.
getChildAt
index
Returns the child display object instance that exists at the specified index.
index
Int
The index position of the child object.
The child display object at the specified index position.
getChildByCid
sjsId
getChildIndex
child
Returns the index position of a child DisplayObject instance.
child
DisplayObject
The DisplayObject instance to identify.
The index position of the child display object to identify.
getChildren
[selector]
Gets all the HTML elements children of this object.
[selector]
String
optional
You can pass in any type of jQuery selector. If there is no selector passed in it will get all the children of this parent element.
Returns a list of DOMElement's. It will grab all children HTML DOM elements of this object and will create a DOMElement for each DOM child. If the 'data-sjs-id' property exists is on an HTML element a DOMElement will not be created for that element because it will be assumed it already exists as a DOMElement.
getEventListeners
()
ArrayReturns and array of all current event types and there current listeners.
this.getEventListeners();
getQualifiedClassName
()
String
public
Returns the fully qualified class name of an object.
Returns the class name.
let someClass = new SomeClass();
someClass.getQualifiedClassName();
// SomeClass
hasEventListener
type
callback
scope
layout
...rest
The layout method provides a common function to handle updating objects in the view.
...rest
ArrayReturns an instance of itself.
print
()
String
public
Prints out each event listener in the console.log
this.printEventListeners();
// [ClassName] is listening for the 'BaseEvent.change' event.
// [AnotherClassName] is listening for the 'BaseEvent.refresh' event.
removeChild
child
Removes the specified child object instance from the child list of the parent object instance. The parent property of the removed child is set to null and the object is garbage collected if there are no other references to the child. The index positions of any objects above the child in the parent object are decreased by 1.
child
DOMElement
The DisplayObjectContainer instance to remove.
Returns an instance of itself.
removeChildAt
index
Removes the child display object instance that exists at the specified index.
index
Int
The index position of the child object.
removeChildren
()
DOMElement
public
chainable
Removes all child object instances from the child list of the parent object instance. The parent property of the removed children is set to null and the objects are garbage collected if no other references to the children exist.
Returns an instance of itself.
removeEventListener
type
callback
scope
swapChildren
child1
child2
Swaps two DisplayObject's with each other.
child1
DisplayObject
The DisplayObject instance to be swap.
child2
DisplayObject
The DisplayObject instance to be swap.
Returns an instance of itself.
swapChildrenAt
index1
index2
Swaps child objects at the two specified index positions in the child list. All other child objects in the display object container remain in the same index positions.
index1
Int
The index position of the first child object.
index2
Int
The index position of the second child object.
Returns an instance of itself.