Add attribute to change the constraint component used by physics-grab-proto

Author: diarmidmackenzie

reaction_components/prototypes/physics-grab-proto.js

@@ -1,7 +1,8 @@
 // base code used by grabbable for physics interactions
 module.exports = {
   schema: {
-    usePhysics: {default: 'ifavailable'}
+    usePhysics: {default: 'ifavailable'},
+    constraintComponentName: {default: 'constraint'}
   },
   physicsInit: function () {
     this.constraints = new Map()
@@ -19,7 +20,7 @@ module.exports = {
     if (this.data.usePhysics !== 'never' && this.el.body &&
         evt.detail.hand.body && !this.constraints.has(evt.detail.hand)) {
       const newConId = Math.random().toString(36).substr(2, 9)
-      this.el.setAttribute('constraint__' + newConId, {
+      this.el.setAttribute(this.data.constraintComponentName + '__' + newConId, {
         target: evt.detail.hand
       })
       this.constraints.set(evt.detail.hand, newConId)
@@ -32,7 +33,7 @@ module.exports = {
   physicsEnd: function (evt) {
     let constraintId = this.constraints.get(evt.detail.hand)
     if (constraintId) {
-      this.el.removeAttribute('constraint__' + constraintId)
+      this.el.removeAttribute(this.data.constraintComponentName + '__' + constraintId)
       this.constraints.delete(evt.detail.hand)
     }
   },