mpx 中手写一个关联组件 relations 使用

//mpx ?resolve找到component组件hash路径 
import tabbarItem from '../tabbar-item/index?resolve'  

createComponent({
	relations : {
      [ tabbarItem ] : {
        type : 'descendant',
        linked : function ( target ) {
          var _this = this;
          
          this.items.push(target)
          
          setTimeout(() => {
            _this.setActiveItem()
          })
        },
        unlinked : function ( target ) {
          var _this2 = this;
          this.items = this.items.filter(function ( item ) {
            return item !== target;
          });
          setTimeout(function () {
            _this2.setActiveItem();
          });
        }
      }
    }
})

import tabbar from '../tabbar/index?resolve' 
createComponent({
    relations: {
      [tabbar]:{
        type: 'ancestor'
			}
    }
})

let parent = this.getRelationNodes([tabbar])[0]