AjaxUpLoad.js实现文件上传

• Wrapper for FireBug's console.log
  */

function log() {
if (typeof(console) != 'undefined' && typeof(console.log) == 'function') {
Array.prototype.unshift.call(arguments,'[Ajax Upload]');
console.log(Array.prototype.join.call(arguments,' '));
}
}

/**

• Attaches event to a dom element.
• @param {Element} el
• @param type event name
• @param fn callback This refers to the passed element
  */

function addEvent(el,type,fn) {
if (el.addEventListener) {
el.addEventListener(type,fn,false);
} else if (el.attachEvent) {
el.attachEvent('on' + type,function () {
fn.call(el);
});
} else {
throw new Error('not supported or DOM not loaded');
}
}

/**

• Attaches resize event to a window,limiting
• number of event fired. Fires only when encounteres
• delay of 100 after series of events.
• Some browsers fire event multiple times when resizing
• http://www.quirksmode.org/dom/events/resize.html
• @param fn callback This refers to the passed element
  */

function addResizeEvent(fn) {
var timeout;

addEvent(window,'resize',function () {
if (timeout) {
clearTimeout(timeout);
}
timeout = setTimeout(fn,100);
});
}

// Needs more testing,will be rewriten for next version
// getOffset function copied from jQuery lib (http://jquery.com/)
if (document.documentElement.getBoundingClientRect) {
// Get Offset using getBoundingClientRect
// http://ejohn.org/blog/getboundingclientrect-is-awesome/
var getOffset = function (el) {
var box = el.getBoundingClientRect();
var doc = el.ownerDocument;
var body = doc.body;
var docElem = doc.documentElement; // for ie
var clientTop = docElem.clientTop || body.clientTop || 0;
var clientLeft = docElem.clientLeft || body.clientLeft || 0;

// In Internet Explorer 7 getBoundingClientRect property is treated as physical,// while others are logical. Make all logical,like in IE8.
var zoom = 1;
if (body.getBoundingClientRect) {
var bound = body.getBoundingClientRect();
zoom = (bound.right - bound.left) / body.clientWidth;
}

if (zoom > 1) {
clientTop = 0;
clientLeft = 0;
}

var top = Box.top / zoom + (window.pageYOffset || docElem && docElem.scrollTop / zoom || body.scrollTop / zoom) - clientTop,left = Box.left / zoom + (window.pageXOffset || docElem && docElem.scrollLeft / zoom || body.scrollLeft / zoom) - clientLeft;

return {
top: top,left: left
};
};
} else {
// Get offset adding all offsets
var getOffset = function (el) {
var top = 0,left = 0;
do {
top += el.offsetTop || 0;
left += el.offsetLeft || 0;
el = el.offsetParent;
} while (el);

return {
left: left,top: top
};
};
}

/**

• Returns left,top,right and bottom properties describing the border-Box,* in pixels,with the top-left relative to the body
• @param {Element} el
• @return {Object} Contains left,right,bottom
  */

function getBox(el) {
var left,bottom;
var offset = getOffset(el);
left = offset.left;
top = offset.top;

right = left + el.offsetWidth;
bottom = top + el.offsetHeight;

return {
left: left,right: right,top: top,bottom: bottom
};
}

/**

• Helper that takes object literal
• and add all properties to element.style
• @param {Element} el
• @param {Object} styles
  */

function addStyles(el,styles) {
for (var name in styles) {
if (styles.hasOwnProperty(name)) {
el.style[name] = styles[name];
}
}
}

/**

• Function places an absolutely positioned
• element on top of the specified element
• copying position and dimentions.
• @param {Element} from
• @param {Element} to
  */

function copyLayout(from,to) {
var Box = getBox(from);

addStyles(to,{
position: 'absolute',left: Box.left + 'px',top: Box.top + 'px',width: from.offsetWidth + 'px',height: from.offsetHeight + 'px'
});
}

/**

• Creates and returns element from html chunk
• Uses innerHTML to create an element
  */
  var toElement = (function () {
  var div = document.createElement('div');
  return function (html) {
  div.innerHTML = html;
  var el = div.firstChild;
  return div.removeChild(el);
  };
  })();

/**

• Function generates unique id
• @return unique id
  */
  var getUID = (function () {
  var id = 0;
  return function () {
  return 'ValumsAjaxUpload' + id++;
  };
  })();

/**

• Get file name from path
• @param {String} file path to file
• @return filename
  */

function fileFromPath(file) {
return file.replace(/.*(\/|\)/,"");
}

/**

• Get file extension lowercase
• @param {String} file name
• @return file extenstion
  */

function getExt(file) {
return (-1 !== file.indexOf('.')) ? file.replace(/.*[.]/,'') : '';
}

function hasClass(el,name) {
var re = new RegExp('\b' + name + '\b');
return re.test(el.className);
}

function addClass(el,name) {
if (!hasClass(el,name)) {
el.className += ' ' + name;
}
}

function removeClass(el,name) {
var re = new RegExp('\b' + name + '\b');
el.className = el.className.replace(re,'');
}

function removeNode(el) {
el.parentNode.removeChild(el);
}

/**

• Easy styling and uploading
• @constructor
• @param button An element you want convert to
• upload button. Tested dimentions up to 500x500px
• @param {Object} options See defaults below.
  */
  window.AjaxUpload = function (button,options) {
  this._settings = {
  // Location of the server-side upload script
  action: 'upload.PHP',// File upload name
  name: 'userfile',// Additional data to send
  data: {},// Submit file as soon as it's selected
  autoSubmit: true,// The type of data that you're expecting back from the server.
  // html and xml are detected automatically.
  // Only useful when you are using json data as a response.
  // Set to "json" in that case.
  responseType: false,// Class applied to button when mouse is hovered
  hoverClass: 'hover',// Class applied to button when AU is disabled
  disabledClass: 'disabled',// When user selects a file,useful with autoSubmit disabled
  // You can return false to cancel upload
  onChange: function (file,extension) {},// Callback to fire before file is uploaded
  // You can return false to cancel upload
  onSubmit: function (file,// Fired when file upload is completed
  // WARNING! DO NOT USE "FALSE" STRING AS A RESPONSE!
  onComplete: function (file,response) {}
  };

// Merge the users options with our defaults
for (var i in options) {
if (options.hasOwnProperty(i)) {
this._settings[i] = options[i];
}
}

// button isn't necessary a dom element
if (button.jquery) {
// jQuery object was passed
button = button[0];
} else if (typeof button == "string") {
if (/^#.*/.test(button)) {
// If jQuery user passes #elementId don't break it
button = button.slice(1);
}

button = document.getElementById(button);
}

if (!button || button.nodeType !== 1) {
throw new Error("Please make sure that you're passing a valid element");
}

if (button.nodeName.toUpperCase() == 'A') {
// disable link
addEvent(button,'click',function (e) {
if (e && e.preventDefault) {
e.preventDefault();
} else if (window.event) {
window.event.returnValue = false;
}
});
}

// DOM element
this._button = button;
// DOM element
this._input = null;
// If disabled clicking on button won't do anything
this._disabled = false;

// if the button was disabled before refresh if will remain
// disabled in FireFox,let's fix it
this.enable();

this._rerouteClicks();
};

// assigning methods to our class
AjaxUpload.prototype = {
setData: function (data) {
this._settings.data = data;
},disable: function () {
addClass(this._button,this._settings.disabledClass);
this._disabled = true;

var nodeName = this._button.nodeName.toUpperCase();
if (nodeName == 'INPUT' || nodeName == 'BUTTON') {
this._button.setAttribute('disabled','disabled');
}

// hide input
if (this._input) {
// We use visibility instead of display to fix problem with Safari 4
// The problem is that the value of input doesn't change if it
// has display none when user selects a file
this._input.parentNode.style.visibility = 'hidden';
}
},enable: function () {
removeClass(this._button,this._settings.disabledClass);
this._button.removeAttribute('disabled');
this._disabled = false;

},/**

• Creates invisible file input
• that will hover above the button
• */ _createInput: function () { var self = this;

var input = document.createElement("input");
input.setAttribute('type','file');
input.setAttribute('name',this._settings.name);

addStyles(input,{
'position': 'absolute',// in Opera only 'browse' button
// is clickable and it is located at
// the right side of the input
'right': 0,'margin': 0,'padding': 0,'fontSize': '480px','cursor': 'pointer'
});

var div = document.createElement("div");
addStyles(div,{
'display': 'block','position': 'absolute','overflow': 'hidden','opacity': 0,// Make sure browse button is in the right side
// in Internet Explorer
'direction': 'ltr',//Max zIndex supported by Opera 9.0-9.2
'zIndex': 2147483583
});

// Make sure that element opacity exists.
// Otherwise use IE filter
if (div.style.opacity !== "0") {
if (typeof(div.filters) == 'undefined') {
throw new Error('Opacity not supported by the browser');
}
div.style.filter = "alpha(opacity=0)";
}

addEvent(input,'change',function () {

if (!input || input.value === '') { 
 return; 
} 

// Get filename from input,<a href="/tag/required/" target="_blank" class="keywords">required</a>     
// as some browsers have path instead of it   
var file = fileFromPath(input.value); 

if (false === self._settings.onChange.call(self,file,getExt(file))) { 
 self._clearInput(); 
 return; 
} 

// Submit form when value is changed 
if (self._settings.autoSubmit) { 
 self.submit(); 
} 

});

addEvent(input,'mouSEOver',function () {
addClass(self._button,self._settings.hoverClass);
});

addEvent(input,'mouSEOut',function () {
removeClass(self._button,self._settings.hoverClass);

// We use visibility instead of display to fix problem with Safari 4 
// The problem is that the value of input doesn't change if it 
// has display none when user selects a file    
input.parentNode.style.visibility = 'hidden'; 

});

div.appendChild(input);
document.body.appendChild(div);

this._input = input;
},_clearInput: function () {
if (!this._input) {
return;
}

// this._input.value = ''; Doesn't work in IE6
removeNode(this._input.parentNode);
this._input = null;
this._createInput();

removeClass(this._button,this._settings.hoverClass);
},/**

• Function makes sure that when user clicks upload button, the this._input is clicked instead
  /
  _rerouteClicks: function () {
  var self = this;

// IE will later display 'access denied' error
// if you use using self._input.click()
// other browsers just ignore click()

addEvent(self._button,function () {
if (self._disabled) {
return;
}

if (!self._input) { 
 self._createInput(); 
} 

var div = self._input.parentNode; 
copyLayout(self._button,div); 
div.style.visibility = 'visible'; 

});

// commented because we now hide input on mouseleave
/**

• When the window is resized the elements
• can be misaligned if button position depends
• on window size
  */
  //addResizeEvent(function(){
  // if (self._input){
  // copyLayout(self._button,self._input.parentNode);
  // }
  //});

},/**

• Creates iframe with unique name
• @return {Element} iframe
  */
  _createIframe: function () {
  // We can't use getTime,because it sometimes return
  // same value in safari :(
  var id = getUID();

// We can't use following code as the name attribute
// won't be properly registered in IE6,and new window
// on form submit will open
// var iframe = document.createElement('iframe');
// iframe.setAttribute('name',id);

var iframe = toElement('