Example tutorial of Bootstrap modal pop-up box

Previous words

In the Bootstrap framework, modal pop-up boxes are collectively called Modal. This pop-up effect is visible in most web site interactions. For example, clicking a button will pop up a box. The pop-up box may be a file description, it may have button operations, or it may pop up a picture. This article will introduce in detail the Bootstrap modal pop-up box

structural analysis

【Related video recommendation:Bootstrap tutorial】

Bootstrap The modal pop-up boxes in the framework use "modal", "modal-dialog" and "modal-content" styles respectively, and the real content of the pop-up window is placed in "modal-content", which mainly includes three Part:

　☑ The head of the pop-up box, generally represented by "modal-header", mainly includes the title and the close button

　☑ The body of the pop-up box, generally represented by "modal-body", pop-up The main content of the box

　☑ The pop-up box footer is generally represented by "modal-footer", which mainly places the operation buttons

<p class="modal show"><p class="modal-dialog"><p class="modal-content"><p class="modal-header"><button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span></button><h4 class="modal-title">模态弹出窗标题</h4></p><p class="modal-body"><p>模态弹出窗主体内容</p></p><p class="modal-footer"><button type="button" class="btn btn-default" data-dismiss="modal">关闭</button><button type="button" class="btn btn-primary">保存</button></p></p><!-- /.modal-content --></p><!-- /.modal-dialog --></p><!-- /.modal -->

For pop-up windows, modal-content is the key to style. It mainly sets the border, margin, background color and shadow styles of the pop-up window

.modal-content {
  position: relative;
  background-color: #fff;
  -webkit-background-clip: padding-box;  background-clip: padding-box;
  border: 1px solid #999;
  border: 1px solid rgba(0, 0, 0, .2);
  border-radius: 6px;
  outline: 0;
  -webkit-box-shadow: 0 3px 9px rgba(0, 0, 0, .5);  box-shadow: 0 3px 9px rgba(0, 0, 0, .5);
}

In addition, the three part style settings of modal-header, modal-body and modal-footer in modal-content As follows

.modal-header {
  min-height: 16.42857143px;
  padding: 15px;
  border-bottom: 1px solid #e5e5e5;
}.modal-header .close {
  margin-top: -2px;
}.modal-title {
  margin: 0;
  line-height: 1.42857143;
}.modal-body {
  position: relative;
  padding: 15px;
}.modal-footer {
  padding: 15px;
  text-align: right;
  border-top: 1px solid #e5e5e5;
}

These three parts mainly control some spacing styles. The modal-footer is used to place buttons, so the included buttons are also styled at the bottom

.modal-footer .btn + .btn {
  margin-bottom: 0;
  margin-left: 5px;
}.modal-footer .btn-group .btn + .btn {
  margin-left: -1px;
}.modal-footer .btn-block + .btn-block {
  margin-left: 0;
}

Triggering method

As we all know, the modal pop-up window will appear when the page is loaded. , is hidden in the page, and only certain actions (events) can trigger the display of the modal pop-up window. There are two implementation methods in the Bootstrap framework

Before introducing the triggering method, we must first explain the two methods .show and .fade. Only the modal pop-up window that is hidden by default can trigger its display

.fade {opacity: 0;
-webkit-transition: opacity .15s linear;
-o-transition: opacity .15s linear;
transition: opacity .15s linear;
}.show {display: block!important;
}

[Method 1]

To declare a modal pop-up window, you only need to customize two necessary attributes: data-toggle and data-target (declarative triggering methods in bootstrap generally rely on these custom data-xxx attributes. For example, data-toggle="" or data-dismiss="")

　data-toggle must be set to modal (toggle Chinese translation is trigger);

Data-target can be set to the CSS selector or the ID value of the modal pop-up window. Generally, it is set to the ID of the modal pop-up window. value, because the ID value is a unique value

<!-- 触发模态弹出窗的元素 --><button type="button" data-toggle="modal" data-target="#mymodal" class="btn btn-primary">点击</button><!-- 模态弹出窗 --><p class="modal fade" id="mymodal"><p class="modal-dialog"><p class="modal-content"><p class="modal-header"><button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span></button><h4 class="modal-title">模态弹出窗标题</h4></p><p class="modal-body"><p>模态弹出窗主体内容</p></p><p class="modal-footer"><button type="button" class="btn btn-default" data-dismiss="modal">关闭</button><button type="button" class="btn btn-primary">保存</button></p></p><!-- /.modal-content --></p><!-- /.modal-dialog --></p><!-- /.modal -->

[Method 2]

The modal pop-up window that triggers can also be a link element, then you can use the link element’s own The href attribute replaces the data-target attribute

However, it is recommended to use the unified use of data-target to trigger

<!-- 触发模态弹出窗的元素 --><a data-toggle="modal" href="#mymodal" class=" btn btn-primary" >点击</a><!-- 模态弹出窗 --><p class="modal fade" id="mymodal"><p class="modal-dialog"><p class="modal-content"><p class="modal-header"><button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span></button><h4 class="modal-title">模态弹出窗标题</h4></p><p class="modal-body"><p>模态弹出窗主体内容</p></p><p class="modal-footer"><button type="button" class="btn btn-default" data-dismiss="modal">关闭</button><button type="button" class="btn btn-primary">保存</button></p></p><!-- /.modal-content --></p><!-- /.modal-dialog --></p><!-- /.modal -->

Size

The Bootstrap framework provides different modal pop-up windows. Size, one is the large size style "modal-lg" and the other is the small size style "modal-sm". Slightly adjusted in its structure

　[Note].bs-example-modal-lg and .bs-example-modal-sm are custom names, not required

<!-- 大尺寸模态弹出窗 --><p class="modal fade bs-example-modal-lg" tabindex="-1" role="dialog" aria-labelledby="myLargeModalLabel" aria-hidden="true"><p class="modal-dialog modal-lg">   <p class="modal-content"> ... </p></p></p><!-- 小尺寸模态弹出窗 --><p class="modal fade bs-example-modal-sm" tabindex="-1" role="dialog" aria-labelledby="mySmallModalLabel" aria-hidden="true"><p class="modal-dialog modal-sm">   <p class="modal-content"> ... </p></p></p>

<button type="button" class="btn btn-primary" data-toggle="modal" data-target=".bs-example-modal-lg">大尺寸</button><button type="button" class="btn btn-primary" data-toggle="modal" data-target="#myModal">默认尺寸</button><button type="button" class="btn btn-primary" data-toggle="modal" data-target=".bs-example-modal-sm">小尺寸</button><p class="modal fade" id="myModal"><p class="modal-dialog"><p class="modal-content"><p class="modal-body"><p>小火柴的蓝色理想</p></p></p></p></p><p class="modal fade bs-example-modal-lg"><p class="modal-dialog modal-lg"><p class="modal-content"><p class="modal-body"><p>小火柴的蓝色理想</p></p></p></p></p><p class="modal fade bs-example-modal-sm"><p class="modal-dialog modal-sm"><p class="modal-content"><p class="modal-body"><p>小火柴的蓝色理想</p></p></p></p></p>

CSS parsing

　The "modal pop-up box" in bootstrap has the following characteristics:

1. The modal pop-up window is fixed in the browser.

　2. Click the full-screen button on the right. In the full-screen state, the width of the modal pop-up window is adaptive, and the modal-dialog is horizontally centered.

　3. When the browser window is larger than 768px, the width of the modal pop-up window is 600px

　4. The background of the modal pop-up window often has a transparent masking effect

　5. When the pop-up window is triggered, the pop-up window gradually emerges from top to bottom and appears in front of the page

[Fixed in the browser]

.modal {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1050;
  display: none;
  overflow: hidden;
  -webkit-overflow-scrolling: touch;
  outline: 0;
}

[Horizontal centering]

.modal-dialog {
  position: relative;
  width: auto;
  margin: 10px;
}

[When the browser window is larger than 768px, the width of the modal pop-up window is 600px]

@media (min-width: 768px) {
  .modal-dialog {
    width: 600px;margin: 30px auto;
  }
  .modal-content {-webkit-box-shadow: 0 5px 15px rgba(0, 0, 0, .5);box-shadow: 0 5px 15px rgba(0, 0, 0, .5);
  }
  .modal-sm {width: 300px;
  }}

[Mask]

When the pop-up window pops up, it is &lt ;body> element adds the .modal-open class to override the default scrolling behavior of the page, and also automatically generates a .modal-backdrop element to provide an available Click the area, click this area to close the modal box

.modal-open {overflow: hidden;
}

.modal-backdrop {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1040;
  background-color: #000;
}

Added a transition animation to it, from fade to in, changing the opacity value from 0 to 0.5

.modal-backdrop.fade {
  filter: alpha(opacity=0);
  opacity: 0;
}.modal-backdrop.in {
  filter: alpha(opacity=50);
  opacity: .5;
}

[Animation effect]

The animation content of the pop-up window is from the top value position of -25% to the top:0 position

.modal.fade .modal-dialog {
  -webkit-transition: -webkit-transform .3s ease-out;   -o-transition:      -o-transform .3s ease-out;  transition:         transform .3s ease-out;
  -webkit-transform: translate3d(0, -25%, 0);   -o-transform: translate3d(0, -25%, 0);  transform: translate3d(0, -25%, 0);
}.modal.in .modal-dialog {
  -webkit-transform: translate3d(0, 0, 0);   -o-transform: translate3d(0, 0, 0);  transform: translate3d(0, 0, 0);
}

If you do not need the animation effect when the modal box pops up (fade in Fade out effect), delete the .fade class

<!-- 触发模态弹出窗的元素 --><button type="button" data-toggle="modal" data-target="#mymodal" class="btn btn-primary">点击</button><!-- 模态弹出窗 --><p class="modal" id="mymodal"><p class="modal-dialog"><p class="modal-content"><p class="modal-header"><button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span></button><h4 class="modal-title">模态弹出窗标题</h4></p><p class="modal-body"><p>模态弹出窗主体内容</p></p><p class="modal-footer"><button type="button" class="btn btn-default" data-dismiss="modal">关闭</button><button type="button" class="btn btn-primary">保存</button></p></p><!-- /.modal-content --></p><!-- /.modal-dialog --></p><!-- /.modal -->

Parameter description

In addition to controlling the modal pop-up window through data-toggle and data-target, The Bootstrap framework also provides other custom data-attributes for modal pop-up boxes to control modal pop-up windows. The relevant instructions for the custom properties of the Modal pop-up window are as follows

This parameter can be set on the button or the pop-up window. For convenience, generally,

is set on the button [Note] The attribute value must be enclosed in quotation marks, such as data-backdrop="false"

If you want to support the esc key to close the pop-up window , you need to set tabindex="-1"

on the pop-up window

<button type="button" data-toggle="modal" data-target="#mymodal1" class="btn btn-primary">默认样式</button><button type="button" data-toggle="modal" data-target="#mymodal2" data-backdrop="false" class="btn btn-primary">无蒙版</button><button type="button" data-toggle="modal" data-target="#mymodal3" data-keyboard="false" class="btn btn-primary">ESC失效</button><button type="button" data-toggle="modal" data-target="#mymodal4" data-show="false" class="btn btn-primary">弹窗默认不显示</button><p class="modal fade"  tabindex="-1" id="mymodal1"><p class="modal-dialog"><p class="modal-content"><p class="modal-header"><button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span></button><h4 class="modal-title">小火柴的蓝色理想</h4></p>        
<p class="modal-body"><p>好的代码像粥一样，都是用时间熬出来的</p></p></p></p></p><p class="modal fade"  
tabindex="-1" id="mymodal2"><p class="modal-dialog"><p class="modal-content"><p class="modal-header"><button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;
</span><span class="sr-only">Close</span></button><h4 class="modal-title">小火柴的蓝色理想</h4></p>        
<p class="modal-body"><p>好的代码像粥一样，都是用时间熬出来的</p></p></p></p></p><p class="modal fade"  
tabindex="-1" id="mymodal3"><p class="modal-dialog"><p class="modal-content"><p class="modal-header"><button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;
</span><span class="sr-only">Close</span></button><h4 class="modal-title">小火柴的蓝色理想</h4></p>        
<p class="modal-body"><p>好的代码像粥一样，都是用时间熬出来的</p></p></p></p></p><p class="modal fade"  
tabindex="-1" id="mymodal4"><p class="modal-dialog"><p class="modal-content"><p class="modal-header"><button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;
</span><span class="sr-only">Close</span></button><h4 class="modal-title">小火柴的蓝色理想</h4></p>        
<p class="modal-body"><p>好的代码像粥一样，都是用时间熬出来的</p></p></p></p></p>

JS触发

　　除了使用自定义属性data-触发模态弹出框之外，还可以通过JavaScript方法来触发模态弹出窗。比如说给按钮设置一个单击事件，然后触发模态弹出窗 

　　只需一行 JavaScript 代码，即可通过元素的 id myModal 调用模态框

$('#myModal').modal()

<button type="button" class="btn btn-primary">点击</button><p class="modal fade"  
tabindex="-1" id="mymodal"><p class="modal-dialog"><p class="modal-content"><p class="modal-header"><button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;
</span><span class="sr-only">Close</span></button><h4 class="modal-title">小火柴的蓝色理想</h4></p>        
<p class="modal-body"><p>好的代码像粥一样，都是用时间熬出来的</p></p></p></p></p><script>$(function(){
    $(".btn").click(function(){
        $("#mymodal").modal();
    });
});</script>

　　使用JavaScript触发模态弹出窗时，Bootstrap框架提供了一些设置，主要包括属性设置、参数设置和事件设置

【属性设置】

　　模态弹出窗默认支持的自定义属性主要有

　　不想让用户按ESC键关闭模态弹出窗，可以这样做 

$(function(){
    $(".btn").click(function(){
        $("#mymodal").modal({
            keyboard:false});
    });
});

【参数设置】

　　在Bootstrap框架中还为模态弹出窗提供了三种参数设置，具体说明如下

<button type="button" class="btn btn-primary" id="btn" style="position:absolute;z-index:9999">打开(关闭)</button>
<p class="modal"  tabindex="-1" id="mymodal" >
    <p class="modal-dialog">
        <p class="modal-content">
            <p class="modal-header">
                <button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;
                </span><span class="sr-only">Close</span></button>
                <h4 class="modal-title">小火柴的蓝色理想</h4>
            </p>        
            <p class="modal-body">
                <p>好的代码像粥一样，都是用时间熬出来的</p>
            </p>
        </p>
    </p>
</p>
<script>;$(function(){
    $("#btn").click(function(){
         $("#mymodal").modal("toggle");
    });
});</script>

【事件设置】

　　模态弹窗还支持五种类型的事件，分别是模态弹出窗的弹出前、弹出后，关闭前、关闭后及远端数据加载后，具体描述如下： 

<button type="button" class="btn btn-primary" id="btn" style="position:absolute;z-index:9999">打开</button><p class="modal"  
tabindex="-1" id="mymodal" ><p class="modal-dialog"><p class="modal-content"><p class="modal-header"><button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;
</span><span class="sr-only">Close</span></button><h4 class="modal-title">小火柴的蓝色理想</h4></p>        
<p class="modal-body"><p>好的代码像粥一样，都是用时间熬出来的</p></p></p></p></p><script>;$(function(){
    $("#btn").click(function(){
         $("#mymodal").modal("toggle");
    });
    $('#mymodal').on('hide.bs.modal', function(){
        $("#btn").html("打开");
    });
    $('#mymodal').on('show.bs.modal', function(){
        $("#btn").html("关闭");
    });    
});</script>

JS解析

【1】IIFE

　　使用立即调用函数，防止插件内代码外泄，从而形成一个闭环，并且只能从jQuery的fn里进行扩展

+function ($) {//使用es5严格模式'use strict';//}(window.jQuery);

【2】初始设置

  var Modal = function (element, options) {
  this.options             
  = options//options是设置选项this.$body               
  = $(document.body)//body元素this.$element            
  = $(element)////element表示modal弹出框容器及内容元素this.$dialog             
  = this.$element.find('.modal-dialog')//弹窗对象this.$backdrop           
  = null //蒙版对象this.isShown             
  = null //弹窗是否显示的标识this.originalBodyPad     
  = null //body的padding-right标识this.scrollbarWidth      
  = 0 //滚动条宽度为0this.ignoreBackdropClick = false //默认蒙板可点击
  //如果设置了remote，就加载remote指定url的内容到modal-content样式的元素内，并触发loaded.bs.modal事件
  if (this.options.remote) {      
  this.$element
        .find('.modal-content')
        .load(this.options.remote, $.proxy(function () {          
        this.$element.trigger('loaded.bs.modal')
        }, this))
    }
  }  //组件版本号3.3.7
  Modal.VERSION  = '3.3.7'  //动画持续时间300ms
  Modal.TRANSITION_DURATION = 300  //蒙版动画持续时间150ms
  Modal.BACKDROP_TRANSITION_DURATION = 150  //默认设置
  Modal.DEFAULTS = {
    backdrop: true, //显示蒙版keyboard: true, //按ESC键关闭弹窗show: true //单击触发元素时打开弹窗
  }

【3】插件核心代码

　　主要是Modal核心类函数的定义、默认参数的定义和9个原型方法的定义，这9个原型方法主要是处理弹窗的反转、打开、关闭和弹窗背景设置、取消等操作

  // 反转弹窗(打开或关闭)
  Modal.prototype.toggle = function (_relatedTarget) {//如果弹窗处于显示状态，则调用hide()方法，关闭它；否则，调用show()方法，打开弹窗return this.isShown ? this.hide() : this.show(_relatedTarget)
  }  // 打开弹窗
  Modal.prototype.show = function (_relatedTarget) {//保存this值var that = this//定义弹窗前的触发事件
  var e    = $.Event('show.bs.modal', { relatedTarget: _relatedTarget })//打开弹窗前，触发事件
  this.$element.trigger(e)// 如果已经打开了（或者曾经被阻止过），则退出执行，后续代码不做处理
  if (this.isShown || e.isDefaultPrevented()) 
  return//设置弹窗显示标识为true
  this.isShown = truethis.checkScrollbar()this.setScrollbar()this.$body.addClass('modal-open')//处理键盘事件，主要是设置按esc键时是否关闭弹窗
  this.escape()this.resize()// 如果单击了元素内的子元素（带有[data-dismiss="modal"]属性），则关闭弹窗
  this.$element.on('click.dismiss.bs.modal', '[data-dismiss="modal"]', $.proxy(this.hide, this))//点击弹窗时，如果鼠标的目标是当前弹窗，则将默认蒙板不可点击的标识置为true，并不可再设置
  this.$dialog.on('mousedown.dismiss.bs.modal', function () {
      that.$element.one('mouseup.dismiss.bs.modal', function (e) {
      if ($(e.target).is(that.$element)) that.ignoreBackdropClick = true  })
    })//绘制蒙版后，处理以下代码this.backdrop(function () {      
    // 判断浏览器是否支持动画，并且弹窗是否设置了动画过渡效果（是否有fade样式）     
    var transition = $.support.transition && that.$element.hasClass('fade')      
    // 如果modal弹窗没有父容器，则将它附加到body上  
    if (!that.$element.parent().length) {
        that.$element.appendTo(that.$body)
      }      // 显示modal弹窗      that.$element
        .show()
        .scrollTop(0)
      that.adjustDialog()      // 如果支持动画，强制刷新UI现场，重绘弹窗  if (transition) {
        that.$element[0].offsetWidth
      }      // 给modal弹窗添加in样式，和modal样式一起  that.$element.addClass('in')      // 强制给弹窗设定焦点      that.enforceFocus()      // 打开弹窗显示后的触发事件  var e = $.Event('shown.bs.modal', { relatedTarget: _relatedTarget })
      transition ?that.$dialog //找到弹窗元素  .one('bsTransitionEnd', function () {// 如果支持动画，则动画结束以后给弹窗内的元素设置焦点，并触发shown事件that.$element.trigger('focus').trigger(e)
          })
          .emulateTransitionEnd(Modal.TRANSITION_DURATION) :// 否则直接设置焦点，并触发shown事件  that.$element.trigger('focus').trigger(e)
    })
  }  // 关闭弹窗
  Modal.prototype.hide = function (e) {//阻止冒泡
  if (e) e.preventDefault()//定义关闭弹窗前的触发事件
  e = $.Event('hide.bs.modal')//关闭弹窗前触发事件
  this.$element.trigger(e)// 如果已经关闭了（或者曾经被阻止过），则退出执行，后续代码不做处理
  if (!this.isShown || e.isDefaultPrevented()) return//设置显示状态标识为false
  this.isShown = false//处理键盘事件，主要是设置按Esc键的时候是否关闭弹窗
  this.escape()this.resize()//取消所有的focusin.bs.modal事件
  $(document).off('focusin.bs.modal')this.$element
      .removeClass('in') //删除in样式  
      .off('click.dismiss.bs.modal') //取消dismiss的单击事件  
      .off('mouseup.dismiss.bs.modal')//取消dismiss的鼠标抬起事件//取消dismiss的鼠标放下事件
      this.$dialog.off('mousedown.dismiss.bs.modal')//如果支持动画，则动画结束以后再关闭，否则直接关闭
      $.support.transition && this.$element.hasClass('fade') ?      this.$element
        .one('bsTransitionEnd', $.proxy(this.hideModal, this))
        .emulateTransitionEnd(Modal.TRANSITION_DURATION) :      this.hideModal()
  }  //强制弹窗处于焦点状态
  Modal.prototype.enforceFocus = function () {
    $(document)      // 禁用所有的focusin事件，防止无限循环  .off('focusin.bs.modal') 
      .on('focusin.bs.modal', $.proxy(function (e) {
      if (this.$element[0] !== e.target && !this.$element.has(e.target).length) {          
      // 如果处于焦点的元素不是当前元素（或不包含当前元素），则强制给当前元素设置焦点  
      this.$element.trigger('focus')
        }
      }, this))
  }  //按Esc键是否退出的处理
  Modal.prototype.escape = function () {
  if (this.isShown && this.options.keyboard) {      //如果弹窗是打开状态，并且keyboard选项为true，则说明允许按ESC键可以关闭弹窗  
  this.$element.on('keydown.dismiss.bs.modal', $.proxy(function (e) {//检测键盘事件，如果是ESC(keycode=27)，则关闭
  e.which == 27 && this.hide()
      }, this))
    } else if (!this.isShown) {      // 否则，取消键盘事件检测  
    this.$element.off('keydown.dismiss.bs.modal')
    }
  }

  Modal.prototype.resize = function () {if (this.isShown) {
      $(window).on('resize.bs.modal', $.proxy(this.handleUpdate, this))
    } else {
      $(window).off('resize.bs.modal')
    }
  }  //关闭弹窗
  Modal.prototype.hideModal = function () {
  var that = this//关闭弹窗
  this.$element.hide()this.backdrop(function () {      //移除body上的modal-open样式 
  that.$body.removeClass('modal-open')
      that.resetAdjustments()
      that.resetScrollbar()      //关闭以后，触发hidden事件  
      that.$element.trigger('hidden.bs.modal')
    })
  }    

  //删除蒙版，关闭弹窗时触发
  Modal.prototype.removeBackdrop = function () {// 删除蒙版
  this.$backdrop && this.$backdrop.remove()// 设置蒙版对象为null
  this.$backdrop = null
  }  

  //添加蒙版，打开弹窗时触发
  Modal.prototype.backdrop = function (callback) {
  var that = this//是否设置了动画过渡效果，如果是则将animate设置为fade
  var animate = this.$element.hasClass('fade') ? 'fade' : ''//如果是打开状态，并且设置了backdrop参数
  if (this.isShown && this.options.backdrop) {      //定义动画标识  
  var doAnimate = $.support.transition && animate      // 在body上定义蒙版p元素，并附加fade标识以支持动画  
  this.$backdrop = $(document.createElement('p'))
        .addClass('modal-backdrop ' + animate)
        .appendTo(this.$body)      //蒙版被单击时进行判断：如果backdrop参数为static，则强制将弹窗设置为售点；否则，关闭弹窗  
        this.$element.on('click.dismiss.bs.modal', $.proxy(function (e) {if (this.ignoreBackdropClick) {          
        this.ignoreBackdropClick = false  return}if (e.target !== e.currentTarget) returnthis.options.backdrop == 'static'
          ? this.$element[0].focus()
          : this.hide()
      }, this))      // 如果支持动画，强制刷新UI现场，重绘弹窗  if (doAnimate) this.$backdrop[0].offsetWidth 
      //添加in样式  this.$backdrop.addClass('in')      //如果没有回调，则直接返回  
      if (!callback) 
      return  // 如果支持动画，则动画结束执行回调函数；否则，直接执行回调函数  
      doAnimate ?this.$backdrop
          .one('bsTransitionEnd', callback)
          .emulateTransitionEnd(Modal.BACKDROP_TRANSITION_DURATION) :
        callback()      //如果是关闭状态，但蒙版对象依然还存在  
        } 
        else if (!this.isShown && this.$backdrop) {      //去除in样式  
        this.$backdrop.removeClass('in')      
        var callbackRemove = function () {
        that.removeBackdrop()
        callback && callback()
      }      // 如果支持动画，则动画结束执行回调函数；否则，直接执行回调函数  
      $.support.transition && this.$element.hasClass('fade') ?this.$backdrop
          .one('bsTransitionEnd', callbackRemove)
          .emulateTransitionEnd(Modal.BACKDROP_TRANSITION_DURATION) :
        callbackRemove()

    } else if (callback) {
      callback()
    }
  }

【4】滚动条处理

　　在弹窗插件中，使用了大量的代码对滚动条进行处理

  Modal.prototype.handleUpdate = function () {this.adjustDialog()
  }  //处理因为滚动条而使弹窗位置不固定问题
  Modal.prototype.adjustDialog = function () {//如果元素的高度大于页面的高度，即溢出屏幕，则modalIsOverflowing置为true
  var modalIsOverflowing = this.$element[0].scrollHeight > document.documentElement.clientHeight//将元素的paddingLeft和paddingRight设置为scrollbarWidth
  this.$element.css({
      paddingLeft:  !this.bodyIsOverflowing && modalIsOverflowing ? this.scrollbarWidth : '',
      paddingRight: this.bodyIsOverflowing && !modalIsOverflowing ? this.scrollbarWidth : ''})
  }  //重置调节器
  Modal.prototype.resetAdjustments = function () {//将元素的paddingLeft和paddingRight置为空this.$element.css({
      paddingLeft: '',
      paddingRight: ''})
  }  //检查滚动条
  Modal.prototype.checkScrollbar = function () {//fullWindowWidth储存页面宽度
  var fullWindowWidth = window.innerWidth//IE8-浏览器不支持innerWidth属性
  if (!fullWindowWidth) {      //使用getBoundingClientRect方法来获得页面宽度   
  var documentElementRect = document.documentElement.getBoundingClientRect()
      fullWindowWidth = documentElementRect.right - Math.abs(documentElementRect.left)
    }//如果有滚动条，则bodyIsOverflowing置为true
    this.bodyIsOverflowing = document.body.clientWidth < fullWindowWidth//将scrollbarWidth置为实际的滚动条宽度
    this.scrollbarWidth = this.measureScrollbar()
  }  //用来为body元素设置padding-right的值，防止body元素被scrollbar阻挡
  Modal.prototype.setScrollbar = function () {
  var bodyPad = parseInt((this.$body.css('padding-right') || 0), 10)this.originalBodyPad = document.body.style.paddingRight || ''//如果页面存在滚动条，则body的padding-right设置为默认的padding-right加上滚动条的宽度
  if (this.bodyIsOverflowing) 
  this.$body.css('padding-right', bodyPad + this.scrollbarWidth)
  }  //重置滚动条
  Modal.prototype.resetScrollbar = function () {//将body的padding-right值设置为null
  this.$body.css('padding-right', this.originalBodyPad)
  } 
  
  //测量滚动条宽度
  Modal.prototype.measureScrollbar = function () {var scrollDiv = document.createElement('p')
    scrollDiv.className = 'modal-scrollbar-measure'this.$body.append(scrollDiv)//滚动条宽度等于offetWidth 
    - clientWidthvar scrollbarWidth = scrollDiv.offsetWidth 
    - scrollDiv.clientWidththis.$body[0].removeChild(scrollDiv)return scrollbarWidth
  }

【5】jQuery插件定义

　　在jQuery上定义插件，有点特殊的代码是options参数的收集和合并，主要收集了3个部分：插件的默认参数DEFAULTS、modal元素上的data-属性，执行插件时传入的option对象，这三个部分的优先级依次升高

  function Plugin(option, _relatedTarget) {//根据选择器，遍历所有符合规则的元素
  return this.each(function () {      
  var $this   = $(this)      //获取自定义属性bs.modal的值  
  var data    = $this.data('bs.modal')      //将插件的默认参数DEFAULTS、modal元素上的data-属性，执行插件时传入的option对象，这三种值合并到一起，作为options参数  //后面的参数的优先级高于前面的参数  
  var options = $.extend({}, Modal.DEFAULTS, $this.data(), typeof option == 'object' && option)      
  //如果值不存在，则将Modal实例设置为bs.modal值  if (!data) $this.data('bs.modal', (data = new Modal(this, options)))      
  //如果option传递了string，则表示要执行某个方法  
  if (typeof option == 'string') data[option](_relatedTarget)      else if (options.show) data.show(_relatedTarget)
    })
  }  var old = $.fn.modal  //保留其他库的$.fn.modal代码(如果定义的话)，以便在noConflict之后可以继续使用该老代码
  $.fn.modal             = Plugin  
  //重设插件构造器，可以通过该属性获取插件的真实类函数
  $.fn.modal.Constructor = Modal

【6】防冲突处理

  $.fn.modal.noConflict = function () {//恢复以前的旧代码$.fn.modal = old//将$.fn.modal.noConflict()设置为Bootstrap的Modal插件return this
  }

【7】绑定触发事件

  //监测所有拥有自定义属性data-toggle="modal"的元素上的单击事件
  $(document).on('click.bs.modal.data-api', '[data-toggle="modal"]', function (e) {
  var $this   = $(this)//获取href属性值
  var href    = $this.attr('href')//获取data-target属性值，如果没有，则获取href值，该值是所弹出元素的idvar 
  $target = $($this.attr('data-target') || (href && href.replace(/.*(?=#[^\s]+$)/, ''))) //如果弹窗元素上已经弹窗实例(即弹出过一次了)，则设置option值为字符串toggle，否则将remote值(如果有的话)、弹窗元素上的自定义属性值集合、触发元素上的自定义属性值集合，合并为option对象var option  = $target.data('bs.modal') ? 'toggle' : $.extend({ remote: !/#/.test(href) && href }, $target.data(), $this.data())//如果是a链接，则阻止其默认行为if ($this.is('a')) e.preventDefault()
    $target.one('show.bs.modal', function (showEvent) {      if (showEvent.isDefaultPrevented()) return 
      //定义一次hidden事件，给所单击元素设置focus  $target.one('hidden.bs.modal', function () {
        $this.is(':visible') && $this.trigger('focus')
      })
    })
    Plugin.call($target, option, this)
  })

}(jQuery);

 

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