The problem with using the plugin in vue

This is the problem I submitted last week at … work-demo/.
Requesting data to the $ interface when calling vue When you use gantt.parse() to render data later, you will get an error.
The specific example is as follows.

        let params = new URLSearchParams();
        params.append('orderId', this.$route.params.orderId);
        this.$'/api/proPlan/groupPlanTree', params, {emulateJSON: true})
          .then((res) => {
            if ( === true) {
              let data =;
              // let taskData = {};
              let links = [];
              for (const i in data) {
                let linksData = {
                  id: data[i].id,
                  source: data[i].id,
                  target: data[i].parent,
                  type: '0',
                  lag: 0
              let taskData = {
                data: data,
                links: links
              this.tasks = taskData;
              this.$nextTick(function () {

Reporting error under Chrome:
vue.esm.js?efeb:591 [Vue warn]: Error in mounted hook: “TypeError: Cannot read property ‘length’ of undefined”

found in

—> at src\components\gantt\gantt.vue
at src\components\gantt\ganttHome.vue

at node_modules\element-ui\packages\container\src\main.vue… (1 recursive calls)
at src\components\index\index.vue
at src\App.vue

TypeError: Cannot read property ‘length’ of undefined
at o._parseInner (dhtmlxgantt.js?1c57:11)
at o.parse (dhtmlxgantt.js?1c57:11)
at n.t._process_loading (dhtmlxgantt.js?1c57:11)
at n.t.on_load (dhtmlxgantt.js?1c57:11)
at n.t.parse (dhtmlxgantt.js?1c57:11)
at VueComponent.mounted (gantt.vue?17f0:215)
at callHook (vue.esm.js?efeb:2921)
at Object.insert (vue.esm.js?efeb:4158)
at invokeInsertHook (vue.esm.js?efeb:5960)
at VueComponent.patch [as patch] (vue.esm.js?efeb:6179)

I tried to add your code in official demo and another instances. Although, I receive the error message, it is different and relates to “params” variable. Please send me full vue.js package so it can be reproduced locally and so we’ll be able to see what might be wrong.