The onload event occurs when an object has been loaded.
onload is most often used within the <body> element to execute a script once a web page has completely loaded all content (including images, script files, CSS files, etc.).
In the first case, a new (anonymous) function is created at each loop turn. In the second case, the same previously declared function is used as an event handler. This results in smaller memory consumption. Moreover, in the first case, since no reference to the anonymous functions is kept, it is not possible to call
element.removeEventListener because we do not have a reference to the handler, while in the second case, it's possible to do myElement.removeEventListener("click", processEvent, false).
If true, useCapture indicates that the user wishes to initiate capture. After initiating capture, all events of the specified type will be dispatched to the registered listener before being dispatched to any EventTarget beneath it in the DOM tree. Events which are bubbling upward through the tree will not trigger a listener designated to use capture. See DOM Level 3 Events for a detailed explanation. If not specified, useCapture defaults to false. Note: For event listeners attached to the event target; the event is in the target phase, rather than capturing and bubbling phases. Events in the target phase will trigger all listeners on an element regardless of the useCapture parameter.
Note: useCapture became optional only in more recent versions of the major browsers; for example, it was not optional prior to Firefox 6. You should provide this parameter for broadest compatibility.
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wantsUntrusted - If
true, the listener will receive synthetic events dispatched by web content (the default isfalsefor chrome andtruefor regular web pages). This parameter is only available in Gecko and is mainly useful for the code in add-ons and the browser itself. See Interaction between privileged and non-privileged pages for an example.
This topic: Sandbox > TestingWiki
Topic revision: 05 Jun 2014, glm83
Topic revision: 05 Jun 2014, glm83
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