小程序全局变量更新触发页面更新（引入小程序全局事件监听）

小程序全局事件监听及触发使用

解决app.globalData 全局变量更新触发页面及组件更新

创建目录：utils/events.js

var event = {};

const $on = function(params) {
  if (!params) {
    return false;
  }
  if (!params.name) {
    console.error("事件监听未设置名称 属性key=name");
    return false;
  }
  if (!params.success) {
    console.error("事件监听未设置回调函数 属性key=success");
    return false;
  }
  if (!params.tg) {
    console.error("事件监听未设置目标对象   属性key=tg");
    return false;
  }
  if (event[params.name]) {
    var list = event[params.name];
    list.push([params.tg, params.success]);
  } else {
    event[params.name] = [
      [params.tg, params.success]
    ];
  }
  pageStatus(params.tg);
}

const $emit = function(params) {
  if (!params) {
    return false;
  }
  if (!params.name) {
    console.error("事件发送未设置名称 属性key=name");
    return false;
  }
  if (event[params.name]) {
    var list = event[params.name];
    list.forEach(item => {
      item[1].call(item[0], params.data);
    })
  }
}

const $remove = function(params) {
  if (!params) {
    return false;
  }
  if (!params.tg) {
    console.error("事件监听未设置目标对象   属性key=tg");
    return false;
  }

  if (params.name && event[params.name]) {
    event[params.name] = event[params.name].filter(a => {
      return a[0] != params.tg;
    })
  } else {
    for (let key in event) {
      event[key] = event[key].filter(a => {
        return a[0] != params.tg;
      })
    }
  }
}

const pageStatus = function(self) {
  if (self["onUnload"]) {
    var s = self["onUnload"];
    self["onUnload"] = function(a) {
      s.call(this, a);
      $remove({
        tg: this
      });
    }
  } else {
    self["onUnload"] = function() {
      $remove({
        tg: this
      });
    }
  }
}

exports.$on = $on;
exports.$emit = $emit;
exports.$remove = $remove;

使用：监听全局事件

import event from '../../utils/events.js'
Component(
{
    lifetimes: {
        attached: function() {
            const that = this
            let voiceState = getApp().globalData.voiceState
            this.setData({ voiceState })
            event.$on({
                name: 'changeVoice',
                tg: this,
                success: (voiceState) => {
                    that.setData({ voiceState })
                }
            })
        },
    },
})

使用： 触发全局事件

<text 
  class="iconfont {{voiceState ? 'icon-shengyinkai' : 'icon-jingyin'}} video-voice" 
  bind:tap="triggerVoice"></text>

import event from '../../utils/events.js'
pages({
    methods: {
        triggerVoice() {
            app.globalData.voiceState = !app.globalData.voiceState
            event.$emit({
                name: 'changeVoice',
                data: app.globalData.voiceState
            })
        }
    }
})