javascript开发随笔3 开发iframe富文本编辑器的一点体会

  就把遇到的问题记录一下。写这篇文章时用的TinyMCE编辑器就很强大,但毕竟是第三方的,项目也考虑了这些,如果做些自定义的东西不太方便。

  1. 判断光标位置的元素(或者选中的部分)的样式。光标位置改变的时候更新工具栏对应按钮的样式。什么情况下光标的位置会改变呢?是键盘方向键和鼠标点击,于是就判断键盘事件和鼠标事件来执行光标移动的处理。

  a. 获得光标位置或选中元素:首先getSelection,创建range。然后获得元素,获取到元素之后就可以或得样式、tagName等等,做更多的操作,运行代码:

  

复制代码 代码如下:

  <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

  <html>

  <head>

  <title></title>

  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

  <style type="text/css">

  p{width:600px;text-align: left;text-indent:2em;line-height:20px;font-size:12px}

  textarea{width:600px;height:100px;font-size:12px;overflow:auto}

  </style>

  </head>

  <body>

  <span style="display:block;height:150px; font-size:12px;line-height:150%">信息</span>

  <script type="text/javascript">

  function createEditor(){

  var iframe = document.createElement('iframe');

  iframe.id = 'iframe';

  iframe.frameBorder = 1;

  iframe.width = 400;

  iframe.height = 200;

  document.body.appendChild(iframe);

  return iframe;

  }

  var bind = function(element,eventType,fn,useCapture){

  useCapture = useCapture || false;

  if(arguments.length < 3){

  return true

  };

  if(window.addEventListener){

  element.addEventListener(eventType, fn, useCapture);

  }else{

  element.attachEvent('on'+eventType,fn, useCapture);

  }

  }

  //from 司徒正美

  var css = document.defaultView ? function(el,style){

  return document.defaultView.getComputedStyle(el, null).getPropertyValue(style)

  } : function(el,style){

  style = style.replace(/\-(\w)/g, function($, $1){

  return $1.toUpperCase();

  });

  return el.currentStyle[style];

  }

  function bindEditor(){

  var iframe = createEditor();

  var ifr_win = iframe.contentWindow;

  var ifr_doc = ifr_win.document;

  var editorContent = '<span style="font-family: 黑体; font-weight: bold;">阿四大四大四</span>大<span style="font-style: italic; text-decoration: underline;">四大四大打算</span>打打<span style="font-style: italic; color: #ff0000;">双打萨斯</span>大师';

  ifr_doc.designMode='On';//可编辑

  ifr_doc.contentEditable = true;

  ifr_doc.open();

  ifr_doc.writeln('<html><head><style type="text/css">body{padding:10px;margin:0;font-size:13px;font-family:宋体;text-align:left;overflow:auto;word-wrap: break-word;cursor:text;background-color: transparent; }body,p,font,div,ul,li {line-height: 1.5;}p,font,div,ul,li {line-height: 1.5;margin:0;padding:0}a{color:#548DD4}</style></head><body>'+ editorContent +'</body></html>');

  ifr_doc.close();

  var getRange = function(){

  var range = window.getSelection ? ifr_win.getSelection() : ifr_win.document.selection;

  if (!range) {

  return {

  node : null,

  range : null,

  text : null

  };

  }

  range = range.createRange ? range.createRange() : range.getRangeAt(0);

  var text = window.getSelection ? range : range.text;

  var rangeNode = null;

  if (range.commonAncestorContainer) {

  rangeNode = range.commonAncestorContainer;

  } else {

  if (range.parentElement) rangeNode = range.parentElement();

  }

  return {

  node : rangeNode,

  range : range,

  text : text

  }

  }

  var info = document.getElementsByTagName('span')[0];

  var getStyle = function(node){

  //console.log(node)

  var html = '';

  html+= '<span style="font-family:'+ css(node,'font-family') +'">字体:'+ css(node,'font-family') + '</span><br />';

  html+= '<span style="color:'+ css(node,'color') +'">颜色:'+ css(node,'color') + '</span><br />';

  html+= '<span style="font-style:'+ css(node,'font-style') +'">斜体:'+ css(node,'font-style') + '</span><br />';

  html+= '<span style="font-weight:'+ css(node,'font-weight') +'">粗体:'+ css(node,'font-weight') + '</span><br />';

  html+= '<span style="text-decoration:'+ css(node,'text-decoration') +'">下划线:'+ css(node,'text-decoration') + '</span><br />';

  html+= 'tagName:'+ node.tagName + ',style:'+ node.getAttribute('style') +'<br />';

  info.innerHTML = html;

  }

  //当光标位置改变时候执行

  var onselectionchange = function(event){

  var e = event || window.event;

  if(!e.keyCode)e.keyCode = e.which;

  //方向键移动光标,获取光标位置的dom

  if((e.keyCode >= 37 && e.keyCode <= 40 )|| e.type == "click"){

  var node = getRange().node;//获取光标位置元素

  if(node !== null){

  while(node.nodeType != 1){

  node = node.parentNode;

  }

  getStyle(node);

  }

  }

  }

  bind(ifr_doc,'click',onselectionchange,false);

  bind(ifr_doc,'keydown',onselectionchange,false);

  }

  window.onload = function(){

  bindEditor();

  }

  </script>

  </body>

  </html>

  2. ie不能保持光标位置,这个是在添加超链接时候出现的问题,当不使用浏览器内置的输入框,光标移动其他的文本域里,ie会失去所选中的部分,无法对选中的部分加链接了,解决办法就是:利用range的getBookmark和moveToBookmark,然后给iframe的document绑定onbeforedeactivate(getBookmark)、onactivate(moveTo),这2个事件的大致意思就是,当被激活和失去激活状态。增加事件之后,就不必保存lastRang或者再其他地方设置bookmark了,可以让ie像其他浏览器一样自动保持光标位置了

  

复制代码 代码如下:

  if(Util.browser.msie){

  Util.bind(this.E.ifr_win.document, "beforedeactivate", function(){

  var Rng = _self.getRange().range;

  _self.rangeBookMark= Rng.getBookmark();

  });

  Util.bind(this.E.ifr_win.document, "activate", function(){

  var Rng = _self.getRange().range;

  Rng.moveToBookmark(_self.rangeBookMark);

  Rng.select();

  _self.rangeBookMark = null;

  });

  }

  3. ie中的撤销与重做 。 当iframe外部有弹出窗口、或者修改html撤销、重做功能将失效。只能归为ie的bug了。。。。也许ie没分清iframe和页面的document,把他们的撤销、重做混道义了。

  如下:

  

复制代码 代码如下:

  <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

  <html>

  <head>

  <title></title>

  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

  <style type="text/css">

  p{width:600px;text-align: left;text-indent:2em;line-height:20px;font-size:12px}

  textarea{width:600px;height:100px;font-size:12px;overflow:auto}

  </style>

  </head>

  <body>

  <span style="display:block;height:150px; font-size:12px;line-height:150%">信息</span>

  <div id="J_tool">

  <input type="button" command="Undo" value="撤销" unselectable="on" />

  <input type="button" command="Redo" value="重做" unselectable="on" />

  <input type="button" command="Bold" value="粗体" unselectable="on" />

  <input type="button" command="Italic" value="斜体" unselectable="on" />

  </div>

  <br />

  <input type="button" onclick="changeLayout()" value="点击下,ie将无法撤销、重做" />

  <br />

  <script type="text/javascript">

  function changeLayout(){

  var popwin = document.getElementById('popwin');

  if(!popwin){

  popwin = document.createElement('div');

  popwin.id = 'popwin';

  popwin.style.cssText = 'display:none;width:300px;height:150px;background-color:#ccc;position:absolute;left:0;top:0px;text-align:center;line-height:150px;';

  popwin.innerHTML = '改变了layoud渲染,ie将无法撤销、重做';

  document.body.appendChild(popwin);

  popwin.onclick= function(){this.style.display = 'none'};

  }

  popwin.style.display = popwin.style.display == 'none' ? 'block' : 'none';

  }

  function createEditor(){

  var iframe = document.createElement('iframe');

  iframe.id = 'iframe';

  iframe.frameBorder = 1;

  iframe.width = 400;

  iframe.height = 200;

  document.body.appendChild(iframe);

  return iframe;

  }

  var bind = function(element,eventType,fn,useCapture){

  useCapture = useCapture || false;

  if(arguments.length < 3){

  return true

  };

  if(window.addEventListener){

  element.addEventListener(eventType, fn, useCapture);

  }else{

  element.attachEvent('on'+eventType,fn, useCapture);

  }

  }

  //from 司徒正美

  var css = document.defaultView ? function(el,style){

  return document.defaultView.getComputedStyle(el, null).getPropertyValue(style)

  } : function(el,style){

  style = style.replace(/\-(\w)/g, function($, $1){

  return $1.toUpperCase();

  });

  return el.currentStyle[style];

  }

  function bindEditor(){

  var iframe = createEditor();

  var ifr_win = iframe.contentWindow;

  var ifr_doc = ifr_win.document;

  var editorContent = '<span style="font-family: 黑体; font-weight: bold;">阿四大四大四</span>大<span style="font-style: italic; text-decoration: underline;">四大四大打算</span>打打<span style="font-style: italic; color: #ff0000;">双打萨斯</span>大师';

  ifr_doc.designMode='On';//可编辑

  ifr_doc.contentEditable = true;

  ifr_doc.open();

  ifr_doc.writeln('<html><head><style type="text/css">body{padding:10px;margin:0;font-size:13px;font-family:宋体;text-align:left;overflow:auto;word-wrap: break-word;cursor:text;background-color: transparent; }body,p,font,div,ul,li {line-height: 1.5;}p,font,div,ul,li {line-height: 1.5;margin:0;padding:0}a{color:#548DD4}</style></head><body>'+ editorContent +'</body></html>');

  ifr_doc.close();

  var getRange = function(){

  var range = window.getSelection ? ifr_win.getSelection() : ifr_win.document.selection;

  if (!range) {

  return {

  node : null,

  range : null,

  text : null

  };

  }

  range = range.createRange ? range.createRange() : range.getRangeAt(0);

  var text = window.getSelection ? range : range.text;

  var rangeNode = null;

  if (range.commonAncestorContainer) {

  rangeNode = range.commonAncestorContainer;

  } else {

  if (range.parentElement) rangeNode = range.parentElement();

  }

  return {

  node : rangeNode,

  range : range,

  text : text

  }

  }

  var info = document.getElementsByTagName('span')[0];

  var getStyle = function(node){

  //console.log(node)

  var html = '';

  html+= '<span style="font-family:'+ css(node,'font-family') +'">字体:'+ css(node,'font-family') + '</span><br />';

  html+= '<span style="color:'+ css(node,'color') +'">颜色:'+ css(node,'color') + '</span><br />';

  html+= '<span style="font-style:'+ css(node,'font-style') +'">斜体:'+ css(node,'font-style') + '</span><br />';

  html+= '<span style="font-weight:'+ css(node,'font-weight') +'">粗体:'+ css(node,'font-weight') + '</span><br />';

  html+= '<span style="text-decoration:'+ css(node,'text-decoration') +'">下划线:'+ css(node,'text-decoration') + '</span><br />';

  html+= 'tagName:'+ node.tagName + ',style:'+ node.getAttribute('style') +'<br />';

  info.innerHTML = html;

  }

  //当光标位置改变时候执行

  var onselectionchange = function(event){

  var e = event || window.event;

  if(!e.keyCode)e.keyCode = e.which;

  //方向键移动光标,获取光标位置的dom

  if((e.keyCode >= 37 && e.keyCode <= 40 )|| e.type == "click"){

  var node = getRange().node;//获取光标位置元素

  if(node !== null){

  while(node.nodeType != 1){

  node = node.parentNode;

  }

  getStyle(node);

  }

  }

  }

  bind(ifr_doc,'click',onselectionchange,false);

  bind(ifr_doc,'keydown',onselectionchange,false);

  bind(document.getElementById('J_tool'),'click',function(event){

  event = event || window.event;

  var target = event.srcElement || event.target;

  var command = target.getAttribute('command');

  var param = target.getAttribute('param') || '';

  ifr_doc.execCommand(command,false,param);

  return false;

  })

  }

  window.onload = function(){

  bindEditor();

  }

  </script>

  </body>

  </html>

  如何解决呢? 只能依靠javascript模拟撤销与重做了。网络这方面的资源还是不少的,就不在此详细说明了