jquery implements the automatic completion drop-down prompt function when entering an email_javascript skills

I remember that when I was working on a project last year, I used the automatic prompt function for email input, so I searched online and found this well written article. Now that I think about it, I reprint it for easy reference.

The widespread use of email is due to the fact that it is free, so many websites will directly use email as their account name when registering

In order to improve user experience, many websites will implement automatic prompt functions for email input.

The effect is as shown in the figure:

Core code (requires jquery support):

(function($){
  $.fn.mailAutoComplete = function(options){
    var defaults = {
      boxClass: "mailListBox", //外部box样式
      listClass: "mailListDefault", //默认的列表样式
      focusClass: "mailListFocus", //列表选样式中
      markCalss: "mailListHlignt", //高亮样式
      zIndex: 1,
      autoClass: true, //是否使用插件自带class样式
      mailArr: ["qq.com","gmail.com","126.com","163.com","hotmail.com","yahoo.com","yahoo.com.cn","live.com","sohu.com","sina.com"], //邮件数组
      textHint: false, //文字提示的自动显示与隐藏
      hintText: "",
      focusColor: "#333"
      //blurColor: "#999"
    };
    var settings = $.extend({}, defaults, options || {});
    
    //页面装载CSS样式
    if(settings.autoClass && $("#mailListAppendCss").size() === 0){
      $('<style id="mailListAppendCss" type="text/css">.mailListBox{border:1px solid #369; background:#fff; font:12px/20px Arial;}.mailListDefault{padding:0 5px;cursor:pointer;white-space:nowrap;}.mailListFocus{padding:0 5px;cursor:pointer;white-space:nowrap;background:#369;color:white;}.mailListHlignt{color:red;}.mailListFocus .mailListHlignt{color:#fff;}</style>').appendTo($("head"));  
    }
    var cb = settings.boxClass, cl = settings.listClass, cf = settings.focusClass, cm = settings.markCalss; //插件的class变量
    var z = settings.zIndex, newArr = mailArr = settings.mailArr, hint = settings.textHint, text = settings.hintText, fc = settings.focusColor, bc = settings.blurColor;
    //创建邮件内部列表内容
    $.createHtml = function(str, arr, cur){
      var mailHtml = "";
      if($.isArray(arr)){
        $.each(arr, function(i, n){
          if(i === cur){
            mailHtml += '<div class="mailHover '+cf+'" id="mailList_'+i+'"><span class="'+cm+'">'+str+'</span>@'+arr[i]+'</div>';  
          }else{
            mailHtml += '<div class="mailHover '+cl+'" id="mailList_'+i+'"><span class="'+cm+'">'+str+'</span>@'+arr[i]+'</div>';  
          }
        });
      }
      return mailHtml;
    };
    //一些全局变量
    var index = -1, s;
    $(this).each(function(){
      var that = $(this), i = $(".justForJs").size();  
      if(i > 0){ //只绑定一个文本框
         return;  
      }
      var w = that.outerWidth(), h = that.outerHeight(); //获取当前对象（即文本框）的宽高
      //样式的初始化
      that.wrap('<span style="display:inline-block;position:relative;"></span>')
        .before('<div id="mailListBox_'+i+'" class="justForJs '+cb+'" style="min-width:'+w+'px;_width:'+w+'px;position:absolute;left:-6000px;top:'+h+'px;z-index:'+z+';"></div>');
      var x = $("#mailListBox_" + i), liveValue; //列表框对象
      that.focus(function(){
        //父标签的层级
        $(this).css("color", fc).parent().css("z-index", z);  
        //提示文字的显示与隐藏
        if(hint && text){
          var focus_v = $.trim($(this).val());
          if(focus_v === text){
            $(this).val("");
          }
        }
        //键盘事件
        $(this).keyup(function(e){
          s = v = $.trim($(this).val());  
          if(/@/.test(v)){
            s = v.replace(/@.*/, "");
          }
          if(v.length > 0){
            //如果按键是上下键
            if(e.keyCode === 38){
              //向上
              if(index <= 0){
                index = newArr.length;  
              }
              index--;
            }else if(e.keyCode === 40){
              //向下
              if(index >= newArr.length - 1){
                index = -1;
              }
              index++;
            }else if(e.keyCode === 13){
              //回车
              if(index > -1 && index < newArr.length){
                //如果当前有激活列表
                $(this).val($("#mailList_"+index).text());  
              }
            }else{
              if(/@/.test(v)){
                index = -1;
                //获得@后面的值
                //s = v.replace(/@.*/, "");
                //创建新匹配数组
                var site = v.replace(/.*@/, "");
                newArr = $.map(mailArr, function(n){
                  var reg = new RegExp(site);  
                  if(reg.test(n)){
                    return n;  
                  }
                });
              }else{
                newArr = mailArr;
              }
            }
            x.html($.createHtml(s, newArr, index)).css("left", 0);
            if(e.keyCode === 13){
              //回车
              if(index > -1 && index < newArr.length){
                //如果当前有激活列表
                x.css("left", "-6000px");  
              }
            }
          }else{
            x.css("left", "-6000px");  
          }
        }).blur(function(){
          if(hint && text){
            var blur_v = $.trim($(this).val());
            if(blur_v === ""){
              $(this).val(text);
            }
          }
          $(this).css("color", bc).unbind("keyup").parent().css("z-index",0);
          x.css("left", "-6000px");  
          
        });  
        //鼠标经过列表项事件
        //鼠标经过
        $(".mailHover").live("mouseover", function(){
          index = Number($(this).attr("id").split("_")[1]);  
          liveValue = $("#mailList_"+index).text();
          x.children("." + cf).removeClass(cf).addClass(cl);
          $(this).addClass(cf).removeClass(cl);
        });
      });

      x.bind("mousedown", function(){
        that.val(liveValue);    
      });
    });
  };
  
})(jQuery);

html example:

<div class="reg_lin1">
<div class="lin1_1">常用邮箱：</div>
<div class="lin1_2"><input type="text" class = "reg_text" id = "email" name = "email"/></div>
<div class="lin1_3"></div>
</div>

jquery code called:

$("#email").mailAutoComplete({
boxClass: "out_box", //外部box样式
listClass: "list_box", //默认的列表样式
focusClass: "focus_box", //列表选样式中
markCalss: "mark_box", //高亮样式
autoClass: false,
textHint: true //提示文字自动隐藏
});

css, you can modify it to the color you want

 <style type="text/css">
    .out_box{border:1px solid #ccc; background:#fff; font:12px/20px Tahoma;}
    .list_box{border-bottom:1px solid #eee; padding:0 5px; cursor:pointer;}
    .focus_box{background:#f0f3f9;}
    .mark_box{color:#c00;}
  </style>

Effect 2:

1. This plug-in is width-adaptive, that is, when the internal text is too long, the width of the external div will be automatically extended. If the width value is set when customizing CSS, width adaptation will fail in non-IE6 browsers;
2. There is no need to set the position attribute, or width and height for the outermost box in the style. The jQuery plug-in has already done this for you. Setting these attributes is not conducive to the display of the effect;
3. This plug-in can only be used on single-line text boxes. Since there are no restrictions on elements of other label types, if the binding object is incorrect, some unexpected situations may occur.
4. Welcome to raise various questions and bugs during use.
--------------------------------------------------
Note: How to use
CSS code:

.out_box{border:1px solid #ccc; background:#fff; font:12px/20px Tahoma;}
.list_box{border-bottom:1px solid #eee; padding:0 5px; cursor:pointer;}
.focus_box{background:#f0f3f9;}
.mark_box{color:#c00;}

JS code:

$("#customTest").mailAutoComplete({
  boxClass: "out_box", //外部box样式
  listClass: "list_box", //默认的列表样式
  focusClass: "focus_box", //列表选样式中
  markCalss: "mark_box", //高亮样式
  autoClass: false,
  textHint: true, //提示文字自动隐藏
  hintText: "请输入邮箱地址"
});

(function($){
  $.fn.mailAutoComplete = function(options){
    var defaults = {
      boxClass: "mailListBox", //外部box样式
      listClass: "mailListDefault", //默认的列表样式
      focusClass: "mailListFocus", //列表选样式中
      markCalss: "mailListHlignt", //高亮样式
      zIndex: 1,
      autoClass: true, //是否使用插件自带class样式
      mailArr: ["qq.com","gmail.com","126.com","163.com","hotmail.com","yahoo.com","yahoo.com.cn","live.com","sohu.com","sina.com"], //邮件数组
      textHint: false, //文字提示的自动显示与隐藏
      hintText: "",
      focusColor: "#333",
      blurColor: "#999"
    };
    var settings = $.extend({}, defaults, options || {});
     
    //页面装载CSS样式
    if(settings.autoClass && $("#mailListAppendCss").size() === 0){
      $('<style id="mailListAppendCss" type="text/css">.mailListBox{border:1px solid #369; background:#fff; font:12px/20px Arial;}.mailListDefault{padding:0 5px;cursor:pointer;white-space:nowrap;}.mailListFocus{padding:0 5px;cursor:pointer;white-space:nowrap;background:#369;color:white;}.mailListHlignt{color:red;}.mailListFocus .mailListHlignt{color:#fff;}</style>').appendTo($("head")); 
    }
    var cb = settings.boxClass, cl = settings.listClass, cf = settings.focusClass, cm = settings.markCalss; //插件的class变量
    var z = settings.zIndex, newArr = mailArr = settings.mailArr, hint = settings.textHint, text = settings.hintText, fc = settings.focusColor, bc = settings.blurColor;
    //创建邮件内部列表内容
    $.createHtml = function(str, arr, cur){
      var mailHtml = "";
      if($.isArray(arr)){
        $.each(arr, function(i, n){
          if(i === cur){
            mailHtml += '<div class="mailHover '+cf+'" id="mailList_'+i+'"><span class="'+cm+'">'+str+'</span>@'+arr[i]+'</div>';  
          }else{
            mailHtml += '<div class="mailHover '+cl+'" id="mailList_'+i+'"><span class="'+cm+'">'+str+'</span>@'+arr[i]+'</div>';  
          }
        });
      }
      return mailHtml;
    };
    //一些全局变量
    var index = -1, s;
    $(this).each(function(){
      var that = $(this), i = $(".justForJs").size(); 
      if(i > 0){ //只绑定一个文本框
        return; 
      }
      var w = that.outerWidth(), h = that.outerHeight(); //获取当前对象（即文本框）的宽高
      //样式的初始化
      that.wrap('<span style="display:inline-block;position:relative;"></span>')
        .before('<div id="mailListBox_'+i+'" class="justForJs '+cb+'" style="min-width:'+w+'px;_width:'+w+'px;position:absolute;left:-6000px;top:'+h+'px;z-index:'+z+';"></div>');
      var x = $("#mailListBox_" + i), liveValue; //列表框对象
      that.focus(function(){
        //父标签的层级
        $(this).css("color", fc).parent().css("z-index", z);  
        //提示文字的显示与隐藏
        if(hint && text){
          var focus_v = $.trim($(this).val());
          if(focus_v === text){
            $(this).val("");
          }
        }
        //键盘事件
        $(this).keyup(function(e){
          s = v = $.trim($(this).val()); 
          if(/@/.test(v)){
            s = v.replace(/@.*/, "");
          }
          if(v.length > 0){
            //如果按键是上下键
            if(e.keyCode === 38){
              //向上
              if(index <= 0){
                index = newArr.length; 
              }
              index--;
            }else if(e.keyCode === 40){
              //向下
              if(index >= newArr.length - 1){
                index = -1;
              }
              index++;
            }else if(e.keyCode === 13){
              //回车
              if(index > -1 && index < newArr.length){
                //如果当前有激活列表
                $(this).val($("#mailList_"+index).text()); 
              }
            }else{
              if(/@/.test(v)){
                index = -1;
                //获得@后面的值
                //s = v.replace(/@.*/, "");
                //创建新匹配数组
                var site = v.replace(/.*@/, "");
                newArr = $.map(mailArr, function(n){
                  var reg = new RegExp(site); 
                  if(reg.test(n)){
                    return n;  
                  }
                });
              }else{
                newArr = mailArr;
              }
            }
            x.html($.createHtml(s, newArr, index)).css("left", 0);
            if(e.keyCode === 13){
              //回车
              if(index > -1 && index < newArr.length){
                //如果当前有激活列表
                x.css("left", "-6000px");  
              }
            }
          }else{
            x.css("left", "-6000px");  
          }
        }).blur(function(){
          if(hint && text){
            var blur_v = $.trim($(this).val());
            if(blur_v === ""){
              $(this).val(text);
            }
          }
          $(this).css("color", bc).unbind("keyup").parent().css("z-index",0);
          x.css("left", "-6000px");  
           
        }); 
        //鼠标经过列表项事件
        //鼠标经过
        $(".mailHover").live("mouseover", function(){
          index = Number($(this).attr("id").split("_")[1]);  
          liveValue = $("#mailList_"+index).text();
          x.children("." + cf).removeClass(cf).addClass(cl);
          $(this).addClass(cf).removeClass(cl);
        });
      });
 
      x.bind("mousedown", function(){
        that.val(liveValue);    
      });
    });
  };
   
})(jQuery);