JavaScript/Notes/IBD: Difference between revisions
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Each event is a property name. The value is a function or null. | Each event is a property name. The value is a function or null. | ||
DOM Elements | |||
<source lang="javascript"> | <source lang="javascript"> | ||
el["onclick"] = function(ev) { | el["onclick"] = function(ev) { | ||
alert(this); | alert(this); | ||
}; | };</source> | ||
</source> | |||
Custom objects | Custom objects | ||
<source lang="javascript"> | <source lang="javascript"> | ||
Revision as of 04:43, 1 November 2013
Interface Based Design
Registering event handlers.
Two ways to Register Events
An event is a notification that something has occurred.
Event Name as a Property
Each event is a property name. The value is a function or null.
DOM Elements <source lang="javascript"> el["onclick"] = function(ev) {
alert(this);
};</source>
Custom objects <source lang="javascript"> userPicker.onuserselected= function(ev) {
console.log(ev.user + " chosen.");
}; </source>
Event Listener Interface
<source lang="javascript"> el.addEventListener("click", function(ev) {
alert("clicked");
}, false); </source>
Custom objects <source lang="javascript"> userPicker.addCallback("onuserselected", function(ev) {
console.log(ev.user + " chosen.");
}); </source>