原生js编写autoComplete插件

最近有提关于下拉选项过多的时候，希望输入关键词，可以搜索内容的需求，但是之前项目太赶，所以也就没有来得及做，因为希望用原生js写一些内容，所以插件是采用了原生js写的思路如下
第一步：fnInit实现初始化一些字段
第二步：加载搜索框的div
第三步：实现search功能，删除原节点并加载新节点
第四步：点击或者回车的时候设置value
代码：
autoComplete.js

/**
 * @summary   AutoComplete
 * @description 输入框自动检索下拉选项
 * @version   0.0.1
 * @file     autoComplete.js
 * @author   cangowu
 * @contact   1138806090@qq.com
 * @copyright  Copyright 2016 cangoWu.
 *
 * 这是一个基于原生js的自动完成搜索的下拉输入框，
 * 可以通过移动鼠标上下键回车以及直接用鼠标点击
 * 选中搜索的选项，在一些关键的地方都有注释
 *
 * 实例参见:
 * CSDN博客：http://blog.csdn.net/wzgdjm/article/details/51122615
 * Github：https://github.com/cangowu/autoComplete
 *
 */
(function () { 

  function AutoComplete() {
    if (!(this instanceof AutoComplete)) {
      return new AutoComplete();
    }
    this.sSearchValue = '';
    this.index = -1;
  } 

  AutoComplete.prototype = {
    fnInit: function (option) {//初始化基本信息
      var oDefault = {
        id: '', //控件id
        data: [], //数据
        paraName: '',
        textFiled: '', //显示的文字的属性名
        valueFiled: '', //获取value的属性名
        style: {}, //显示的下拉div的样式设置
        url: '', //ajax请求的url
        select: function () {
        }, //选择选项时触发的事件
      };
      var _option = option; 

      this.sId = _option.id || oDefault.id;
      this.aData = _option.data || oDefault.data;
      this.paraName = _option.paraName || oDefault.paraName;
      this.sTextFiled = _option.textFiled || oDefault.textFiled;
      this.sValueFiled = _option.valueFiled || oDefault.valueFiled;
      this.style = _option.style || oDefault.style;
      this.sUrl = _option.url || oDefault.url;
      this.fnSelect = _option.select || oDefault.select;
      this.sDivId = this.sId + new Date().getTime();//加载选项额divid 

      //判断如果传入了url,没有传入data数据，就ajax获取数据，否则使用data取数据
      if (this.sUrl !== '' && this.aData.length === 0) {
        var that = this;
        this.util.fnGet(this.sUrl, function (data) {
          console.log(eval(data));
          that.aData = eval(data);
        }, 10);
      } 

      //给aData排序
      var sTextField = this.sTextFiled;
      this.aData.sort(function (a, b) {
        return a[sTextField] > b[sTextField];
      });
      //获取控件
      this.domInput = document.getElementById(this.sId);
      //this.domDiv = document.getElementById(this.sDivId);
    },
    fnRender: function () {//渲染一些必须的节点
      var that = this;
      //生成一个对应的div，承载后面的一些选项的
      if (that.sDivId) {
        var domDiv = document.createElement('div');
        domDiv.id = that.sDivId;
        domDiv.style.background = '#fff';
        domDiv.style.width = that.domInput.offsetWidth - 2 + 'px';
        domDiv.style.position = 'absolute';
        domDiv.style.border = '1px solid #a9a9a9';
        domDiv.style.display = 'none';
        that.util.fnInsertAfter(domDiv, that.domInput); 

        //加载之后才能将domDiv赋值为
        this.domDiv = document.getElementById(this.sDivId);
      }
      //给input添加keyup事件
      that.util.fnAddEvent(that.domInput, 'keyup', function (event) {
        that.fnSearch(event);
      });
    },
    fnSearch: function (event) {
      //判断如果不是回车键，上键下键的时候执行搜索
      if (event.keyCode != 13 && event.keyCode != 38 && event.keyCode != 40) {
        this.fnLoadSearchContent();
        this.fnShowDiv();
      } else {//搜索之后监测键盘事件
        var length = this.domDiv.children.length;
        if (event.keyCode == 40) {
          ++this.index;
          if (this.index >= length) {
            this.index = 0;
          } else if (this.index == length) {
            this.domInput.value = this.sSearchValue;
          }
          this.domInput.value = this.domDiv.childNodes[this.index].text;
          this.fnChangeClass();
        }
        else if (event.keyCode == 38) {
          this.index--;
          if (this.index <= -1) {
            this.index = length - 1;
          } else if (this.index == -1) {
            this.obj.value = this.sSearchValue;
          }
          this.domInput.value = this.domDiv.childNodes[this.index].text;
          this.fnChangeClass();
        }
        else if (event.keyCode == 13) {
          this.fnLoadSearchContent();
          this.fnShowDiv();
          //this.domDiv.style.display = this.domDiv.style.display === 'none' ? 'block' : 'none';
          this.index = -1;
        } else {
          this.index = -1;
        }
      }
    },
    fnLoadSearchContent: function () {
      //删除所有的子节点
      while (this.domDiv.hasChildNodes()) {
        this.domDiv.removeChild(this.domDiv.firstChild);
      }
      //设置search的值
      this.sSearchValue = this.domInput.value;
      //如果值为空的时候选择退出
      var sTrimSearchValue = this.sSearchValue.replace(/(^\s*)|(\s*$)/g, '');
      if (sTrimSearchValue == "") {
        this.domDiv.style.display = 'none';
        return;
      }
      try {
        var reg = new RegExp("(" + sTrimSearchValue + ")", "i");
      }
      catch (e) {
        return;
      }
      //搜索并增加新节点
      var nDivIndex = 0;
      for (var i = 0; i < this.aData.length; i++) {
        if (reg.test(this.aData[i][this.sTextFiled])) {
          var domDiv = document.createElement("div");
          //div.className="auto_onmouseout";
          domDiv.text = this.aData[i][this.sTextFiled];
          domDiv.onclick = this.fnSetValue(this);
          domDiv.onmouseover = this.fnAutoOnMouseOver(this, nDivIndex);
          domDiv.innerHTML = this.aData[i][this.sTextFiled].replace(reg, "<strong>$1</strong>");//搜索到的字符粗体显示
          this.domDiv.appendChild(domDiv);
          nDivIndex++;
        }
      }
    },
    fnSetValue: function (that) {
      return function () {
        that.domInput.value = this.text;
        that.domDiv.style.display = 'none';
      }
    },
    fnAutoOnMouseOver: function (that, idx) {
      return function () {
        that.index = idx;
        that.fnChangeClass();
      }
    },
    fnChangeClass: function () {
      var that = this;
      var length = that.domDiv.children.length;
      for (var j = 0; j < length; j++) {
        if (j != that.index) {
          that.domDiv.childNodes[j].style.backgroundColor = '';
          that.domDiv.childNodes[j].style.color = '#000';
        } else {
          that.domDiv.childNodes[j].style.backgroundColor = 'blue';
          that.domDiv.childNodes[j].style.color = '#fff';
        }
      }
    },
    fnShowDiv: function () {
      if (this.domDiv.children.length !== 0) {
        this.domDiv.style.display = this.domDiv.style.display === 'none' ? 'block' : 'none';
      }
    },
    util: {//公共接口方法
      fnInsertAfter: function (ele, targetEle) {
        var parentnode = targetEle.parentNode || targetEle.parentElement;
        if (parentnode.lastChild == targetEle) {
          parentnode.appendChild(ele);
        } else {
          parentnode.insertBefore(ele, targetEle.nextSibling);
        }
      },
      fnAddEvent: function (ele, evt, fn) {
        if (document.addEventListener) {
          ele.addEventListener(evt, fn, false);
        } else if (document.attachEvent) {
          ele.attachEvent('on' + (evt == "input" ? "propertychange" : evt), fn);
        } else {
          ele['on' + (evt == "input" ? "propertychange" : evt)] = fn;
        }
      },
      fnGet: function (url, fn, timeout) {
        var xhr = null;
        try {
          if (window.XMLHttpRequest) {
            xhr = new XMLHttpRequest();
          } else if (Window.ActiveXObject) { 

            xhr = new ActiveXObject("Msxml2.Xmlhttp");
          }
        } catch (e) {
          //TODO handle the exception
          xhr = new ActiveXObject('Microsoft.Xmlhttp');
        }
        xhr.onreadystatechange = function () {
          if (this.readyState == 4 && this.status == 200) {
            fn.call(this, this.responseText);
          } else {
            setTimeout(function () {
              xhr.abort();
            }, timeout);
          }
        };
        xhr.open('get', url, true);
        xhr.send();
      }
    }
  } 

  window.AutoComplete = function (option) {
    var aOption = Array.prototype.slice.call(arguments);
    for(var i=0;i<aOption.length;i++){
      var autoComplete = new AutoComplete();
      autoComplete.fnInit(aOption[i]);
      autoComplete.fnRender();
    }
  } 

})(window); 

index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body> 

<div>
<input type="text" id="txtTest">
</div>
<br>
<div>
<input type="text" id="txtTest1">
</div> 

<script src="autoComplete.js"></script>
<script> 

  window.onload = function () {
    var option = {
      id: 'txtTest', //控件id
      data: [{
        "id": "1",
        "name": "aaaaa"
      }, {
        "id": "2",
        "name": "bbbbb"
      }, {
        "id": "2",
        "name": "bbb吴bb"
      }, {
        "id": "2",
        "name": "bbbzbb"
      }],
      paraName: 'name',
      textFiled: 'name', //显示的文字的属性名
      valueFiled: 'id', //获取value的属性名
      select: function (val, text) {
        alert(val + '' + text);
      } //选择选项时触发的事件
    };
    var option1 = {
      id: 'txtTest1', //控件id
      url: 'data.json', //数据
      paraName: 'name',
      textFiled: 'name', //显示的文字的属性名
      valueFiled: 'id', //获取value的属性名
      select: function (val, text) {
        alert(val + '' + text);
      } //选择选项时触发的事件
    };
    AutoComplete(option,option1); 

  } 

</script>
</body>
</html> 

data.json

[
 {
  "id": "1",
  "name": "aaaaa"
 },
 {
  "id": "2",
  "name": "bbbbb"
 },
 {
  "id": "3",
  "name": "ccccc"
 }
] 

以上就是本文的全部内容，希望对大家学习javascript程序设计有所帮助。