jquery 本地上传图片预览Demo

/*! * jQuery JavaScript Library v1.4.2 * http://jquery.com/ * * Copyright 2010, John Resig * Dual licensed under the MIT or GPL Version 2 licenses. * http://jquery.org/license * * Includes Sizzle.js * http://sizzlejs.com/ * Copyright 2010, The Dojo Foundation * Released under the MIT, BSD, and GPL Licenses. * * Date: Sat Feb 13 22:33:48 2010 -0500 */ (function( window, undefined ) { // Define a local copy of jQuery var jQuery = function( selector, context ) { // The jQuery object is actually just the init constructor 'enhanced' return new jQuery.fn.init( selector, context ); }, // Map over jQuery in case of overwrite _jQuery = window.jQuery, // Map over the $ in case of overwrite _$ = window.$, // Use the correct document accordingly with window argument (sandbox) document = window.document, // A central reference to the root jQuery(document) rootjQuery, // A simple way to check for HTML strings or ID strings // (both of which we optimize for) quickExpr = /^[^<]*(<[\w\W]+>)[^>]*$|^#([\w-]+)$/, // Is it a simple selector isSimple = /^.[^:#\[\.,]*$/, // Check if a string has a non-whitespace character in it rnotwhite = /\S/, // Used for trimming whitespace rtrim = /^(\s|\u00A0)+|(\s|\u00A0)+$/g, // Match a standalone tag rsingleTag = /^<(\w+)\s*\/?>(?:<\/\1>)?$/, // Keep a UserAgent string for use with jQuery.browser userAgent = navigator.userAgent, // For matching the engine and version of the browser browserMatch, // Has the ready events already been bound? readyBound = false, // The functions to execute on DOM ready readyList = [], // The ready event handler DOMContentLoaded, // Save a reference to some core methods toString = Object.prototype.toString, hasOwnProperty = Object.prototype.hasOwnProperty, push = Array.prototype.push, slice = Array.prototype.slice, indexOf = Array.prototype.indexOf; jQuery.fn = jQuery.prototype = { init: function( selector, context ) { var match, elem, ret, doc; // Handle $(""), $(null), or $(undefined) if ( !selector ) { return this; } // Handle $(DOMElement) if ( selector.nodeType ) { this.context = this[0] = selector; this.length = 1; return this; } // The body element only exists once, optimize finding it if ( selector === "body" && !context ) { this.context = document; this[0] = document.body; this.selector = "body"; this.length = 1; return this; } // Handle HTML strings if ( typeof selector === "string" ) { // Are we dealing with HTML string or an ID? match = quickExpr.exec( selector ); // Verify a match, and that no context was specified for #id if ( match && (match[1] || !context) ) { // HANDLE: $(html) -> $(array) if ( match[1] ) { doc = (context ? context.ownerDocument || context : document); // If a single string is passed in and it's a single tag // just do a createElement and skip the rest ret = rsingleTag.exec( selector ); if ( ret ) { if ( jQuery.isPlainObject( context ) ) { selector = [ document.createElement( ret[1] ) ]; jQuery.fn.attr.call( selector, context, true ); } else { selector = [ doc.createElement( ret[1] ) ]; } } else { ret = buildFragment( [ match[1] ], [ doc ] ); selector = (ret.cacheable ? ret.fragment.cloneNode(true) : ret.fragment).childNodes; } return jQuery.merge( this, selector ); // HANDLE: $("#id") } else { elem = document.getElementById( match[2] ); if ( elem ) { // Handle the case where IE and Opera return items // by name instead of ID if ( elem.id !== match[2] ) { return rootjQuery.find( selector ); } // Otherwise, we inject the element directly into the jQuery object this.length = 1; this[0] = elem; } this.context = document; this.selector = selector; return this; } // HANDLE: $("TAG") } else if ( !context && /^\w+$/.test( selector ) ) { this.selector = selector; this.context = document; selector = document.getElementsByTagName( selector ); return jQuery.merge( this, selector ); // HANDLE: $(expr, $(...)) } else if ( !context || context.jquery ) { return (context || rootjQuery).find( selector ); // HANDLE: $(expr, context) // (which is just equivalent to: $(context).find(expr) } else { return jQuery( context ).find( selector ); } // HANDLE: $(function) // Shortcut for document ready } else if ( jQuery.isFunction( selector ) ) { return rootjQuery.ready( selector ); } if (selector.selector !== undefined) { this.selector = selector.selector; this.context = selector.context; } return jQuery.makeArray( selector, this ); }, // Start with an empty selector selector: "", // The current version of jQuery being used jquery: "1.4.2", // The default length of a jQuery object is 0 length: 0, // The number of elements contained in the matched element set size: function() { return this.length; }, toArray: function() { return slice.call( this, 0 ); }, // Get the Nth element in the matched element set OR // Get the whole matched element set as a clean array get: function( num ) { return num == null ? // Return a 'clean' array this.toArray() : // Return just the object ( num < 0 ? this.slice(num)[ 0 ] : this[ num ] ); }, // Take an array of elements and push it onto the stack // (returning the new matched element set) pushStack: function( elems, name, selector ) { // Build a new jQuery matched element set var ret = jQuery(); if ( jQuery.isArray( elems ) ) { push.apply( ret, elems ); } else { jQuery.merge( ret, elems ); } // Add the old object onto the stack (as a reference) ret.prevObject = this; ret.context = this.context; if ( name === "find" ) { ret.selector = this.selector + (this.selector ? " " : "") + selector; } else if ( name ) { ret.selector = this.selector + "." + name + "(" + selector + ")"; } // Return the newly-formed element set return ret; }, // Execute a callback for every element in the matched set. // (You can seed the arguments with an array of args, but this is // only used internally.) each: function( callback, args ) { return jQuery.each( this, callback, args ); }, ready: function( fn ) { // Attach the listeners jQuery.bindReady(); // If the DOM is already ready if ( jQuery.isReady ) { // Execute the function immediately fn.call( document, jQuery ); // Otherwise, remember the function for later } else if ( readyList ) { // Add the function to the wait list readyList.push( fn ); } return this; }, eq: function( i ) { return i === -1 ? this.slice( i ) : this.slice( i, +i + 1 ); }, first: function() { return this.eq( 0 ); }, last: function() { return this.eq( -1 ); }, slice: function() { return this.pushStack( slice.apply( this, arguments ), "slice", slice.call(arguments).join(",") ); }, map: function( callback ) { return this.pushStack( jQuery.map(this, function( elem, i ) { return callback.call( elem, i, elem ); })); }, end: function() { return this.prevObject || jQuery(null); }, // For internal use only. // Behaves like an Array's method, not like a jQuery method. push: push, sort: [].sort, splice: [].splice }; // Give the init function the jQuery prototype for later instantiation jQuery.fn.init.prototype = jQuery.fn; jQuery.extend = jQuery.fn.extend = function() { // copy reference to target object var target = arguments[0] || {}, i = 1, length = arguments.length, deep = false, options, name, src, copy; // Handle a deep copy situation if ( typeof target === "boolean" ) { deep = target; target = arguments[1] || {}; // skip the boolean and the target i = 2; } // Handle case when target is a string or something (possible in deep copy) if ( typeof tar