jquery/jquery

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src/core/ready.js

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3 hrs
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define( [
    "../core",
    "../var/document",
    "../core/readyException",
    "../deferred"
], function( jQuery, document ) {

"use strict";

// The deferred used on DOM ready
var readyList = jQuery.Deferred();

jQuery.fn.ready = function( fn ) {

    readyList
        .then( fn )

        // Wrap jQuery.readyException in a function so that the lookup
        // happens at the time of error handling instead of callback
        // registration.
        .catch( function( error ) {
            jQuery.readyException( error );
        } );

    return this;
};

jQuery.extend( {

    // Is the DOM ready to be used? Set to true once it occurs.
    isReady: false,

    // A counter to track how many items to wait for before
    // the ready event fires. See #6781
    readyWait: 1,

    // Handle when the DOM is ready
    ready: function( wait ) {

        // Abort if there are pending holds or we're already ready
        if ( wait === true ? --jQuery.readyWait : jQuery.isReady ) {
            return;
        }

        // Remember that the DOM is ready
        jQuery.isReady = true;

        // If a normal DOM Ready event fired, decrement, and wait if need be
        if ( wait !== true && --jQuery.readyWait > 0 ) {
            return;
        }

        // If there are functions bound, to execute
        readyList.resolveWith( document, [ jQuery ] );
    }
} );

jQuery.ready.then = readyList.then;

// The ready event handler and self cleanup method
function completed() {
    document.removeEventListener( "DOMContentLoaded", completed );
    window.removeEventListener( "load", completed );
    jQuery.ready();
}

// Catch cases where $(document).ready() is called
// after the browser event has already occurred.
// Support: IE <=9 - 10 only
// Older IE sometimes signals "interactive" too soon
if ( document.readyState === "complete" ||
    ( document.readyState !== "loading" && !document.documentElement.doScroll ) ) {

    // Handle it asynchronously to allow scripts the opportunity to delay ready
    window.setTimeout( jQuery.ready );

} else {

    // Use the handy event callback
    document.addEventListener( "DOMContentLoaded", completed );

    // A fallback to window.onload, that will always work
    window.addEventListener( "load", completed );
}

} );