src/lay/modules/layedit.js
function(tagName, attr, range){
    var iframeDOM = this.document
    ,elem = document.createElement(tagName)
    for(var key in attr){
      elem.setAttribute(key, attr[key]);
    }
    elem.removeAttribute('text');

    if(iframeDOM.selection){ //IE
      var text = range.text || attr.text;
      if(tagName === 'a' && !text) return;
      if(text){
        elem.innerHTML = text;
      }
      range.pasteHTML($(elem).prop('outerHTML')); 
      range.select();
    } else { //非IE
      var text = range.toString() || attr.text;
      if(tagName === 'a' && !text) return;
      if(text){
        elem.innerHTML = text;
      }
      range.deleteContents();
      range.insertNode(elem);
    }
  }
function(tagName, attr, range){
    var iframeDOM = this.document
    ,elem = document.createElement(tagName)
    for(var key in attr){
      elem.setAttribute(key, attr[key]);
    }
    elem.removeAttribute('text');

    if(iframeDOM.selection){ //IE
      var text = range.text || attr.text;
      if(tagName === 'a' && !text) return;
      if(text){
        elem.innerHTML = text;
      }
      range.pasteHTML($(elem).prop('outerHTML')); 
      range.select();
    } else { //非IE
      var text = range.toString() || attr.text;
      if(tagName === 'a' && !text) return;
      if(text){
        elem.innerHTML = text;
      }
      range.deleteContents();
      range.insertNode(elem);
    }
  }
iframe初始化