Move js to form component

js/mixins/form.js

@@ -1,23 +1,53 @@
 export default {
+  props: {
+    initialSelectedSection: String,
+  },
+
   mounted: function() {
     this.$root.$on('field-change', this.handleFieldChange)
   },
 
+  created: function() {
+    this.$root.$on('field-mount', this.handleFieldMount)
+  },
+
   methods: {
     handleFieldChange: function(event) {
-      const { value, name } = event
+      const { name, valid, parent_uid } = event
       if (typeof this[name] !== undefined) {
-        this[name] = value
-        if (event['parent_uid'] === this._uid) {
+        this.fields[name] = valid
+
+        if (parent_uid === this._uid) {
           this.changed = true
         }
       }
+
+      this.validateForm()
+    },
+
+    handleFieldMount: function(event) {
+      const { name, optional } = event
+      this.fields[name] = optional
+    },
+
+    validateForm: function() {
+      const valid = !Object.values(this.fields).some(field => field === false)
+      this.invalid = !valid
+      return valid
+    },
+
+    handleSubmit: function(event) {
+      if (this.invalid) {
+        event.preventDefault()
+      }
     },
   },
 
   data: function() {
     return {
       changed: this.hasChanges,
+      fields: {},
+      invalid: true,
     }
   },