element-ui Tag、Dialog组件源码分析整理笔记(五)

Tag 标签组件

<script>
  export default {
    name: 'ElTag',
    props: {
      text: String,
      closable: Boolean, //是否可关闭
      type: String, //主题
      hit: Boolean, //是否有边框描边
      disableTransitions: Boolean, //是否禁用渐变动画
      color: String, //背景色
      size: String  //尺寸
    },
    methods: {
      handleClose(event) {
        event.stopPropagation();
        this.$emit('close', event);
      }
    },
    computed: {
      tagSize() {
        return this.size || (this.$ELEMENT || {}).size;
      }
    },
    render(h) {
      const classes = [ 'el-tag', this.type ? `el-tag--${this.type}` : '',
        this.tagSize ? `el-tag--${this.tagSize}` : '',
        {'is-hit': this.hit}
      ];
      //最外层包裹的span
      const tagEl = (<span class={classes} style={{backgroundColor: this.color}}>
        { this.$slots.default }
        {
          // closable存在时,返回关闭图标
          this.closable && <i class="el-tag__close el-icon-close" on-click={this.handleClose}></i>
        }
      </span>);
      // disableTransitions存在的话,用transition标签包裹,产生渐变动画
      return this.disableTransitions ? tagEl : <transition name="el-zoom-in-center">{ tagEl }</transition>;
    }
  };
</script>

Dialog 对话框组件

<template>
    <!--transition组件可以给任何元素和组件添加进入/离开过渡-->
  <transition
    name="dialog-fade"
    @after-enter="afterEnter"
    @after-leave="afterLeave">
     <!--包裹dialog的div-->
    <div class="el-dialog__wrapper" v-show="visible" @click.self="handleWrapperClick">
      <div
        role="dialog"
        aria-modal="true"
        :aria-label="title || 'dialog'"
        class="el-dialog"
        :class="[{ 'is-fullscreen': fullscreen, 'el-dialog--center': center }, customClass]"
        ref="dialog"
        :style="style">
         <!--dialog_header包含:标题、关闭按钮-->
        <div class="el-dialog__header">
          <!--标题-->
          <slot name="title">
            <span class="el-dialog__title">{{ title }}</span>
          </slot>
          <!--关闭按钮-->
          <button
            type="button"
            class="el-dialog__headerbtn"
            aria-label="Close"
            v-if="showClose"
            @click="handleClose">
            <i class="el-dialog__close el-icon el-icon-close"></i>
          </button>
        </div>
        <!--中间的内容-->
        <div class="el-dialog__body" v-if="rendered"><slot></slot></div>
        <!--底部内容-->
        <div class="el-dialog__footer" v-if="$slots.footer">
          <slot name="footer"></slot>
        </div>
      </div>
    </div>
  </transition>
</template>

<script>
  import Popup from 'element-ui/src/utils/popup';
  //在控制台输出一些已经移除的属性
  import Migrating from 'element-ui/src/mixins/migrating';
  //触发子组件或者父组件的事件
  import emitter from 'element-ui/src/mixins/emitter';

  export default {
    name: 'ElDialog',

    mixins: [Popup, emitter, Migrating],

    props: {
      title: { //Dialog 的标题,也可通过具名 slot(titlefooter)传入
        type: String,
        default: ''
      },
      modal: { //是否需要遮罩层
        type: Boolean,
        default: true
      },
      modalAppendToBody: { //遮罩层是否插入至 body 元素上,若为 false,则遮罩层会插入至 Dialog 的父元素上
        type: Boolean,
        default: true
      },
      appendToBody: { //Dialog 自身是否插入至 body 元素上。嵌套的 Dialog 必须指定该属性并赋值为 true
        type: Boolean,
        default: false
      },
      lockScroll: { //是否在 Dialog 出现时将 body 滚动锁定
        type: Boolean,
        default: true
      },
      closeOnClickModal: { //是否可以通过点击 modal 关闭 Dialog
        type: Boolean,
        default: true
      },
      closeOnPressEscape: { //是否可以通过按下 ESC 关闭 Dialog
        type: Boolean,
        default: true
      },
      showClose: { //是否显示关闭按钮
        type: Boolean,
        default: true
      },
       String, //Dialog 的宽度
      fullscreen: Boolean, //是否为全屏 Dialog
      customClass: { //Dialog 的自定义类名
        type: String,
        default: ''
      },
      top: { //Dialog CSS 中的 margin-top 值
        type: String,
        default: '15vh'
      },
      beforeClose: Function, //关闭前的回调,会暂停 Dialog 的关闭
      center: { //是否对头部和底部采用居中布局
        type: Boolean,
        default: false
      }
    },

    data() {
      return {
        closed: false
      };
    },

    watch: {
      visible(val) {
        if (val) {
          this.closed = false;
          // Dialog 打开的回调
          this.$emit('open');
          //滚动时,更新弹出框的位置
          this.$el.addEventListener('scroll', this.updatePopper);
          this.$nextTick(() => {
            // 元素的滚动条的垂直位置为0
            this.$refs.dialog.scrollTop = 0;
          });
          //appendToBody为true时,将Dialog插入到body元素上
          if (this.appendToBody) {
            document.body.appendChild(this.$el);
          }
        } else {
          this.$el.removeEventListener('scroll', this.updatePopper);
          if (!this.closed) this.$emit('close');
        }
      }
    },

    computed: {
      style() {
        let style = {};
        //如果不是全屏显示Dialog,Dialog的margin-top等于用户设置的top
        if (!this.fullscreen) {
          style.marginTop = this.top;
          if (this.width) {
            style.width = this.width;
          }
        }
        return style;
      }
    },

    methods: {
      getMigratingConfig() {
        return {
          props: {
            'size': 'size is removed.'
          }
        };
      },
      handleWrapperClick() {
        //closeOnClickModal为false,则不能通过点击 modal 关闭 Dialog,直接返回
        if (!this.closeOnClickModal) return;
        this.handleClose();
      },
      handleClose() {
        // 关闭前的回调,会暂停 Dialog 的关闭
        if (typeof this.beforeClose === 'function') {
          this.beforeClose(this.hide);
        } else {
          this.hide();
        }
      },
      hide(cancel) {
        if (cancel !== false) {
          this.$emit('update:visible', false);
          this.$emit('close');
          this.closed = true;
        }
      },
      // 这里不知道为什么这么写,没太搞懂
      updatePopper() {
        this.broadcast('ElSelectDropdown', 'updatePopper');
        this.broadcast('ElDropdownMenu', 'updatePopper');
      },
      // Dialog 打开动画结束时的回调
      afterEnter() {
        this.$emit('opened');
      },
      // Dialog 关闭动画结束时的回调
      afterLeave() {
        this.$emit('closed');
      }
    },

    mounted() {
      if (this.visible) {
        // rendered这里不是太懂,估计是处理弹出框位置相关的,等后面弄懂后再补充
        this.rendered = true;
        this.open();
        if (this.appendToBody) {
          document.body.appendChild(this.$el);
        }
      }
    },

    destroyed() {
      // if appendToBody is true, remove DOM node after destroy
      if (this.appendToBody && this.$el && this.$el.parentNode) {
        this.$el.parentNode.removeChild(this.$el);
      }
    }
  };
</script>
原文地址:https://www.cnblogs.com/fangnianqin/p/10044439.html