用js实现输入提示功能

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完成有以下功能：

输入字符会把以输入字符开头的提示出来。

支持上下方向键选择提示选项，支持循环

支持绑定一个数组提示，支持ajax传递输入框值请求数据。

支持多个选择的dom元素一块绑定数据实现输入提示。各dom元素也可以单独绑定自己的数据实现输入提示，互不影响。

支持中文。

首先是js的核心部分，其各部分都有较详细的说明，代码如下：

view source print ?

  ;( function (window){              var autoComplete= function (o){            var handler=( function (){                var handler= function (e,o){ return new handler.prototype.init(e,o); };                 handler.prototype={                    e: null , o: null , timer: null , show:0, input: null , popup: null ,                    init: function (e,o){                         this .e=e, this .o=o,                        this .input= this .e.getElementsByTagName( this .o.input)[0],                        this .popup= this .e.getElementsByTagName( this .o.popup)[0],                        this .initEvent();                    },                   match: function (quickExpr,value,source){                        var li = null ;                       for ( var i in source){                           if ( value.length>0 && quickExpr.exec(source[i])!= null ){                               li = document.createElement( 'li' );                               li.innerhtml = '' +source[i]+ 'a>' ;                              this .popup.appendChild(li);                           }                       }                       if ( this .popup.getElementsByTagName( 'a' ).length)                           this .popup.style.display= 'block' ;                       else                            this .popup.style.display= 'none' ;                    },                    ajax: function (type,url,quickExpr,search){                        var xhr = window.ActiveXObject ? new ActiveXObject( "Microsoft.XMLHttp" ) : new XMLHttpRequest();                        xhr.open(type,url, true );                         xhr.setRequestHeader( "Content-Type" , "application/x-www-fORM-urlencoded" );                       var that= this ;                       xhr.onreadystatechange = function (){                           if (xhr.readyState==4) {                                if (xhr.status==200) {                                    var data = eval(xhr.responseText);                                   that.match(quickExpr,search,data);                                 } else {                                    alert( "请求页面异常!" );                                 }                            }                        };                        xhr.send( null );                    },                   fetch: function (ajax,search,quickExpr){                        var that= this ;                        this .ajax(ajax.type,ajax.url+search,quickExpr,search);                   },                    initEvent: function (){                         var that= this ;                       this .input.onfocus = function (){                            if ( this .inputValue) this .value = this .inputValue;                            var value= this .value, quickExpr=RegExp( '^' +value, 'i' ), self= this ;                            var els = that.popup.getElementsByTagName( 'a' );                            if (els.length>0) that.popup.style.display = 'block' ;                            that.timer=setInterval( function (){                                if (value!=self.value){                                    value=self.value;                                    that.popup.innerHTML= '' ;                                    if (value!= '' ){                                       quickExpr=RegExp( '^' +value);                                        if (that.o.source) that.match(quickExpr,value,that.o.source);                                        else if (that.o.ajax) that.fetch(that.o.ajax,value,quickExpr);                                    }                                }                            },200);                        };                       this .input.onblur = function (){                             if ( this .value!= this .defaultValue) this .inputValue = this .value;                            clearInterval(that.timer);                            var current=-1;                             var els = that.popup.getElementsByTagName( 'a' );                            var len = els.length-1;                           var aClick = function (){                               that.input.inputValue = this .firstChild.nodeValue;                                that.popup.innerHTML= '' ;                                that.popup.style.display= 'none' ;                               that.input.focus();                            };                            var aFocus = function (){                                for ( var i=len; i>=0; i--){                                    if ( this .parentNode===that.popup.children[i]){                                       current = i;                                        break ;                                    }                                }                                //that.input.value = this.firstChild.nodeValue;                                for ( var k in that.o.elemCSS.focus){                                    this .style[k] = that.o.elemCSS.focus[k];                                }                            };                           var aBlur= function (){                               for ( var k in that.o.elemCSS.blur)                                   this .style[k] = that.o.elemCSS.blur[k];                            };                            var aKeydown = function (event){                                eventevent = event || window.event;                                 if (current === len && event.keyCode===9){                                     that.popup.style.display = 'none' ;                                } else if (event.keyCode==40){                                     current++;                                    if (current<-1) current=len;                                   if (current>len){                                        current=-1;                                       that.input.focus();                                    } else {                                        that.popup.getElementsByTagName( 'a' )[current].focus();                                    }                                } else if (event.keyCode==38){                                    current--;                                   if (current==-1){                                        that.input.focus();                                   } else if (current<-1){                                        current = len;                                        that.popup.getElementsByTagName( 'a' )[current].focus();                                    } else {                                       that.popup.getElementsByTagName( 'a' )[current].focus();                                    }                                }                            };                            for ( var i=0; i<els.length; i++){                                 els[i].onclick = aClick;                                els[i].onfocus = aFocus;                                els[i].onblur = aBlur;                                els[i].onkeydown = aKeydown;                            }                        };                        this .input.onkeydown = function (event){                           eventevent = event || window.event;                             var els = that.popup.getElementsByTagName( 'a' );                            if (event.keyCode==40){                                if (els[0]) els[0].focus();                            } else if (event.keyCode==38){                               if (els[els.length-1]) els[els.length-1].focus();                            } else if (event.keyCode==9){                                if (event.shifTKEy== true ) that.popup.style.display = 'none' ;                            }                        };                        this .e.onmouseover = function (){ that.show=1; };                        this .e.onmouseout = function (){ that.show=0; };                        addEvent.call(document, 'click' , function (){                            if (that.show==0){                                that.popup.style.display= 'none' ;                            }                        });                     }                };                handlerhandler.prototype.init.prototype=handler.prototype;                 return handler;             })();            if ( this .length){                 for ( var a= this .length-1; a>=0; a--){                     handler( this [a],o);                }            } else {                 handler( this ,o);           }            return this ;       };       return window.autoComplete = autoComplete;               })(window);

其中了一些全局的自定义函数，如addEvent和在例子中将要用到的getElementsByClassName函数如下：

view source print ?

var getElementsByClassName = function (searchClass, node, tag) {            nodenode = node || document, tagtag = tag ? tag.toUpperCase() : "*" ;            if (document.getElementsByClassName){                var temp = node.getElementsByClassName(searchClass);                if (tag== "*" ){                    return temp;               } else {                    var ret = new Array();                    for ( var i=0; i<temp.length; i++)

感谢各位的阅读，以上就是“用js实现输入提示功能”的内容了，经过本文的学习后，相信大家对用js实现输入提示功能这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是编程网，小编将为大家推送更多相关知识点的文章，欢迎关注！