JS原生数据双向绑定实现代码

网络编程 2024/11/20 佚名

3 1 2

代码如下：

<span style="font-family:Times New Roman;font-size:14px;" deep="7"><!DOCTYPE html> 
<html lang="en"> <head> 
  <meta charset="UTF-8"> 
  <title>Demo</title> 
  <script> 
    function DataBinder( object_id ) { 
      // Create a simple PubSub object 
      var pubSub = { 
            callbacks: {}, 
            on: function( msg, callback ) { 
              this.callbacks[ msg ] = this.callbacks[ msg ] || []; 
              this.callbacks[ msg ].push( callback ); 
            }, 
            publish: function( msg ) { 
              this.callbacks[ msg ] = this.callbacks[ msg ] || []; 
              for ( var i = 0, len = this.callbacks[ msg ].length; i < len; i++ ) { 
                this.callbacks[ msg ][ i ].apply( this, arguments ); 
              } 
            } 
          }, 
          data_attr = "bind-" + object_id, 
          message = object_id + ":input", 
          timeIn; 
          changeHandler = function( evt ) { 
            var target = evt.target || evt.srcElement, // IE8 compatibility 
                prop_name = target.getAttribute( data_attr ); 
            if ( prop_name && prop_name !== "" ) { 
              clearTimeout(timeIn); 
              timeIn = setTimeout(function(){ 
                pubSub.publish( message, prop_name, target.value ); 
              },50); 
            } 
          }; 
      // Listen to change events and proxy to PubSub 
      if ( document.addEventListener ) { 
        document.addEventListener( "input", changeHandler, false ); 
      } else { 
        // IE8 uses attachEvent instead of addEventListener 
        document.attachEvent( "oninput", changeHandler ); 
      } 
      // PubSub propagates changes to all bound elements 
      pubSub.on( message, function( evt, prop_name, new_val ) { 
        var elements = document.querySelectorAll("[" + data_attr + "=" + prop_name + "]"), 
            tag_name; 
        for ( var i = 0, len = elements.length; i < len; i++ ) { 
          tag_name = elements[ i ].tagName.toLowerCase(); 
          if ( tag_name === "input" || tag_name === "textarea" || tag_name === "select" ) { 
            elements[ i ].value = new_val; 
          } else { 
            elements[ i ].innerHTML = new_val; 
          } 
        } 
      }); 
      return pubSub; 
    } 
    function DBind( uid ) { 
      var binder = new DataBinder( uid ), 
      user = { 
        // ... 
        attributes: {}, 
        set: function( attr_name, val ) { 
          this.attributes[ attr_name ] = val; 
          // Use the `publish` method 
          binder.publish( uid + ":input", attr_name, val, this ); 
        }, 
        get: function( attr_name ) { 
          return this.attributes[ attr_name ]; 
        }, 
        _binder: binder 
      }; 
      // Subscribe to the PubSub 
      binder.on( uid + ":input", function( evt, attr_name, new_val, initiator ) { 
        if ( initiator !== user ) { 
          user.set( attr_name, new_val ); 
        } 
      }); 
      return user; 
    } 
  </script> 
</head> 
<body> 
<input type="text" bind-1="name" /> 
<span bind-1="name"></span> 
<script> 
  var DBind = new DBind( 1 ); 
  DBind.set( "name", "" ); 
</script> 
</body> 
</html>
</span>

效果示例：