fix: 流程设计表单类型来回切换前端报错的问题

src/views/plugin/workflow/design/index.vue

@@ -32,7 +32,8 @@
                    @click="$router.push('/plugin/workflow/design/form')">没有想要的表单？点击去设计</el-link>
         </template>
         <template #form>
-          <avue-form ref="form2"
+          <avue-form v-if="option && ((option.column && option.column.length > 0) || (option.group && option.group.length > 0))"
+                     ref="form2"
                      v-model="form"
                      :option="option"></avue-form>
         </template>
@@ -172,19 +173,20 @@ export default {
                     this.findObject(this.step1.option.group[0].column, 'formKey').display = true
                     this.findObject(this.step1.option.group[0].column, 'tip').display = true
                     this.findObject(this.step1.option.group[1].column, 'form').display = true
+                    this.step1.option.group[1].display = true
                   } else if (val == 2) {
                     this.findObject(this.step1.option.group[0].column, 'exFormKey').display = true
                     this.findObject(this.step1.option.group[1].column, 'column').display = true
                     this.findObject(this.step1.option.group[0].column, 'formKey').display = false
                     this.findObject(this.step1.option.group[0].column, 'tip').display = false
-                    this.findObject(this.step1.option.group[1].column, 'form').display = false
+                    this.option = {}
                     this.step1.option.group[1].display = true
                   } else if (val == 3) {
                     this.findObject(this.step1.option.group[0].column, 'exFormKey').display = false
                     this.findObject(this.step1.option.group[1].column, 'column').display = false
                     this.findObject(this.step1.option.group[0].column, 'formKey').display = false
                     this.findObject(this.step1.option.group[0].column, 'tip').display = false
-                    this.findObject(this.step1.option.group[1].column, 'form').display = false
+                    this.option = {}
                     this.step1.option.group[1].display = false
                   }
                 }
@@ -205,19 +207,16 @@ export default {
               dicData: [],
               event: {
                 change: (val) => {
-                  this.option = {}
+                  _this.option = { menuBtn: false, readonly: true }
                   if (val) {
                     getFormByKey({ formKey: val }).then(res => {
                       _this.option = { ...eval('(' + res.data.data.content.replace(/this/g, '_this') + ')'), menuBtn: false, readonly: true }
-                      _this.step1.option.group[1].display = true
+                      _this.findObject(this.step1.option.group[1].column, 'form').display = true
-                      setTimeout(() => {
-                        if(_this.$refs.form2) _this.$refs.form2.clearValidate()
-                      })
                     }).catch(() => {
-                      _this.step1.option.group[1].display = false
+                      _this.findObject(this.step1.option.group[1].column, 'form').display = false
                     })
                   } else {
-                    _this.step1.option.group[1].display = false
+                    _this.findObject(this.step1.option.group[1].column, 'form').display = false
                   }
                 }
               },
@@ -231,13 +230,14 @@ export default {
           }, {
             label: '表单预览',
             icon: 'el-icon-view',
-            display: false,
+            display: true,
             arrow: false,
             column: [{
               prop: 'form',
               labelWidth: 0,
               span: 24,
-              formslot: true
+              formslot: true,
+              display: false
             }, {
               prop: 'column',
               labelWidth: '0',