Merge branch 'dev'

Author: levy

src/el-data-tree.vue

@@ -409,7 +409,9 @@ export default {
      */
     collapsable: {
       type: Boolean,
-      default: false
+      default() {
+        return _get(this, '$elDataTreeOptions.collapsable') || false
+      }
     }
   },
   data() {

src/index.js

@@ -5,7 +5,8 @@ import Component from './el-data-tree.vue'
 // the same plugin more than once,
 // so calling it multiple times on the same plugin
 // will install the plugin only once
-Component.install = Vue => {
+Component.install = (Vue, options = {}) => {
+  Vue.prototype.$elDataTreeOptions = options
   Vue.component(Component.name, Component)
 }