如何在已有的画布上载入新的JSON？

我直接更改wfd-vue的data会报错：
vue.runtime.esm.js?2b0e:619 [Vue warn]: Error in callback for watcher "data": "TypeError: Cannot read property 'shape' of undefined"

found in

---> <WfdVue>
       <ElDialog> at packages/dialog/src/component.vue
         <Flow> at src/views/flow/index.vue
           <AppMain> at src/layout/components/AppMain.vue
             <Layout> at src/layout/index.vue
               <App> at src/App.vue
                 <Root>
warn @ vue.runtime.esm.js?2b0e:619
logError @ vue.runtime.esm.js?2b0e:1884
globalHandleError @ vue.runtime.esm.js?2b0e:1879
handleError @ vue.runtime.esm.js?2b0e:1839
run @ vue.runtime.esm.js?2b0e:4570
flushSchedulerQueue @ vue.runtime.esm.js?2b0e:4310
eval @ vue.runtime.esm.js?2b0e:1980
flushCallbacks @ vue.runtime.esm.js?2b0e:1906
Promise.then(异步)
timerFunc @ vue.runtime.esm.js?2b0e:1933
nextTick @ vue.runtime.esm.js?2b0e:1990
queueWatcher @ vue.runtime.esm.js?2b0e:4402
update @ vue.runtime.esm.js?2b0e:4544
notify @ vue.runtime.esm.js?2b0e:730
reactiveSetter @ vue.runtime.esm.js?2b0e:1055
createData @ index.vue?6ced:205
click @ index.vue?150e:286
invokeWithErrorHandling @ vue.runtime.esm.js?2b0e:1854
invoker @ vue.runtime.esm.js?2b0e:2179
invokeWithErrorHandling @ vue.runtime.esm.js?2b0e:1854
Vue.$emit @ vue.runtime.esm.js?2b0e:3888
handleClick @ element-ui.common.js?5c96:9417
invokeWithErrorHandling @ vue.runtime.esm.js?2b0e:1854
invoker @ vue.runtime.esm.js?2b0e:2179
original._wrapper @ vue.runtime.esm.js?2b0e:6917
vue.runtime.esm.js?2b0e:1888 TypeError: Cannot read property 'shape' of undefined
    at base.onMouseUp (drag-canvas.js?398d:115)
    at Graph.method (wrap-behavior.js?eafe:15)
    at doEmit (index.js?7fa2:61)
    at Graph.EventEmitter.emit (index.js?7fa2:64)
    at VueComponent.data (Wfd.vue?c53b:105)
    at Watcher.run (vue.runtime.esm.js?2b0e:4568)
    at flushSchedulerQueue (vue.runtime.esm.js?2b0e:4310)
    at Array.eval (vue.runtime.esm.js?2b0e:1980)
    at flushCallbacks (vue.runtime.esm.js?2b0e:1906)
guozhaolong / wfd-vue

如何在已有的画布上载入新的JSON？ #55
