other / mew-iview

  <template>

      <collapse-transition>

          <ul :class="classes">

              <li>
                  <span :class="arrowClasses" @click="handleExpand">

                      <Icon v-if="showArrow" type="arrow-right-b"></Icon>
                      <Icon v-if="showLoading" type="load-c" class="ivu-load-loop"></Icon>

                  </span>
                  <Checkbox

                          v-if="showCheckbox"
                          :value="data.checked"

                          :indeterminate="data.indeterminate"

                          :disabled="data.disabled || data.disableCheckbox"
                          @click.native.prevent="handleCheck"></Checkbox>

                  <Render v-if="data.render" :render="data.render" :data="data" :node="node"></Render>
                  <Render v-else-if="isParentRender" :render="parentRender" :data="data" :node="node"></Render>

                  <span v-else :class="titleClasses" @click="handleSelect">{{ data.title }}</span>

                  <Tree-node

                          v-if="data.expand"

                          v-for="(item, i) in children"

                          :key="i"

                          :data="item"

                          :multiple="multiple"

                          :show-checkbox="showCheckbox"
                          :children-key="childrenKey">

                  </Tree-node>
              </li>
          </ul>

      </collapse-transition>

  </template>
  <script>
      import Checkbox from '../checkbox/checkbox.vue';

      import Icon from '../icon/icon.vue';

      import Render from './render';

      import CollapseTransition from '../base/collapse-transition';

      import Emitter from '../../mixins/emitter';

      import { findComponentUpward } from '../../utils/assist';

  
      const prefixCls = 'ivu-tree';
  
      export default {
          name: 'TreeNode',
          mixins: [ Emitter ],

          components: { Checkbox, Icon, CollapseTransition, Render },

          props: {
              data: {
                  type: Object,
                  default () {
                      return {};
                  }
              },
              multiple: {
                  type: Boolean,
                  default: false
              },

              childrenKey: {
                  type: String,
                  default: 'children'
              },

              showCheckbox: {
                  type: Boolean,
                  default: false

              }
          },
          data () {
              return {

                  prefixCls: prefixCls

              };
          },

          computed: {
              classes () {
                  return [
                      `${prefixCls}-children`

                  ];

              },
              selectedCls () {
                  return [
                      {
                          [`${prefixCls}-node-selected`]: this.data.selected
                      }
                  ];
              },
              arrowClasses () {
                  return [
                      `${prefixCls}-arrow`,
                      {
                          [`${prefixCls}-arrow-disabled`]: this.data.disabled,

                          [`${prefixCls}-arrow-open`]: this.data.expand

                      }
                  ];
              },
              titleClasses () {
                  return [
                      `${prefixCls}-title`,
                      {
                          [`${prefixCls}-title-selected`]: this.data.selected
                      }
                  ];

              },
              showArrow () {

                  return (this.data[this.childrenKey] && this.data[this.childrenKey].length) || ('loading' in this.data && !this.data.loading);

              },
              showLoading () {
                  return 'loading' in this.data && this.data.loading;

              },
              isParentRender () {
                  const Tree = findComponentUpward(this, 'Tree');
                  return Tree && Tree.render;
              },
              parentRender () {
                  const Tree = findComponentUpward(this, 'Tree');
                  if (Tree && Tree.render) {
                      return Tree.render;
                  } else {
                      return null;
                  }

              },
              node () {
                  const Tree = findComponentUpward(this, 'Tree');
                  if (Tree) {

                      // 将所有的 node（即flatState）和当前 node 都传递
                      return [Tree.flatState, Tree.flatState.find(item => item.nodeKey === this.data.nodeKey)];

                  } else {

                      return [];

                  }

              },
              children () {
                  return this.data[this.childrenKey];

              }
          },
          methods: {
              handleExpand () {

                  const item = this.data;
                  if (item.disabled) return;
  
                  // async loading

                  if (item[this.childrenKey].length === 0) {

                      const tree = findComponentUpward(this, 'Tree');
                      if (tree && tree.loadData) {

                          this.$set(this.data, 'loading', true);
                          tree.loadData(item, children => {
                              this.$set(this.data, 'loading', false);
                              if (children.length) {

                                  this.$set(this.data, this.childrenKey, children);

                                  this.$nextTick(() => this.handleExpand());

                              }
                          });
                          return;
                      }
                  }
  

                  if (item[this.childrenKey] && item[this.childrenKey].length) {

                      this.$set(this.data, 'expand', !this.data.expand);
                      this.dispatch('Tree', 'toggle-expand', this.data);
                  }

              },
              handleSelect () {
                  if (this.data.disabled) return;

                  this.dispatch('Tree', 'on-selected', this.data.nodeKey);

              },
              handleCheck () {

                  if (this.data.disabled) return;
                  const changes = {
                      checked: !this.data.checked && !this.data.indeterminate,
                      nodeKey: this.data.nodeKey
                  };
                  this.dispatch('Tree', 'on-check', changes);

              }

          }
      };

  </script>