[WIP] Polymorphic assocations

packages/strapi-mongoose/lib/index.js

@@ -135,7 +135,18 @@ module.exports = function (strapi) {
                   });
 
                   if (!plugin) {
-                    global[definition.globalName] = instance.model(definition.globalName, collection.schema, definition.collectionName);
+                    // Enhance schema with polymorphic relationships.
+                    const morphs = _.pickBy(definition.loadedModel, model => {
+                      return model.type === 'discriminator';
+                    });
+
+                    if (_.size(morphs) > 0) {
+                      const morph = morphs[Object.keys(morphs)[0]];
+
+                      global[definition.globalName] = global[morph.ref].discriminator(morph.discriminator, collection.schema);
+                    } else {
+                      global[definition.globalName] = instance.model(definition.globalName, collection.schema, definition.collectionName);
+                    }
                   } else {
                     instance.model(definition.globalName, collection.schema, definition.collectionName);
                   }
@@ -195,10 +206,23 @@ module.exports = function (strapi) {
               // Call this callback function after we are done parsing
               // all attributes for relationships-- see below.
               const done = _.after(_.size(definition.attributes), () => {
-                // Generate schema without virtual populate
-                _.set(strapi.config.hook.settings.mongoose, 'collections.' + mongooseUtils.toCollectionName(definition.globalName) + '.schema', new instance.Schema(_.omitBy(definition.loadedModel, model => {
-                  return model.type === 'virtual';
-                })));
+                // Extract discriminator (morphTo side)
+                const discriminators = _.pickBy(definition.loadedModel, model => {
+                  return model.hasOwnProperty('discriminatorKey');
+                });
+
+                const options = {};
+
+                if (_.size(discriminators) > 0) {
+                  options.discriminatorKey = 'type';
+                }
+
+                // Generate schema without virtual populate & discriminators.
+                let schema = new instance.Schema(_.omitBy(definition.loadedModel, model => {
+                  return model.type === 'virtual' || model.type === 'discriminator' || model.hasOwnProperty('discriminatorKey');
+                }), options);
+
+                _.set(strapi.config.hook.settings.mongoose, 'collections.' + mongooseUtils.toCollectionName(definition.globalName) + '.schema', schema);
 
                 loadedAttributes();
               });
@@ -292,6 +316,22 @@ module.exports = function (strapi) {
                     }
                     break;
                   }
+                  case 'morphOne': {
+                    const discriminator = plugin ? `${plugin}_${model.toLowerCase()}` : model.toLowerCase();
+                    const ref = details.plugin ? strapi.plugins[details.plugin].models[details.model].globalId : strapi.models[details.model].globalId;
+
+                    definition.loadedModel[name] = {
+                      type: 'discriminator',
+                      ref,
+                      discriminator
+                    }
+                    break;
+                  }
+                  case 'morphTo': {
+                    definition.loadedModel[name] = {
+                      discriminatorKey: 'kind'
+                    };
+                  }
                   default:
                     break;
                 }

packages/strapi-plugin-users-permissions/models/User.settings.json

@@ -36,6 +36,10 @@
       "via": "users",
       "plugin": "users-permissions",
       "configurable": false
+    },
+    "avatar": {
+      "model": "upload",
+      "via": "related"
     }
   }
 }

packages/strapi-utils/lib/models.js

@@ -94,6 +94,8 @@ module.exports = {
           types.other = 'collectionD';
         } else if (relatedAttribute.hasOwnProperty('model')) {
           types.other = 'model';
+        } else if (relatedAttribute.hasOwnProperty('key')) {
+          types.other = 'morphTo';
         }
       } else if (association.hasOwnProperty('via') && association.hasOwnProperty('model')) {
         types.current = 'modelD';
@@ -111,6 +113,8 @@ module.exports = {
 
               // Break loop
               return false;
+            } else if (attribute.hasOwnProperty('key')) {
+              types.other = 'morphTo'; // MorphTo
             }
           });
         });
@@ -156,9 +160,26 @@ module.exports = {
             }
           });
         });
+      } else if (association.hasOwnProperty('key')) {
+        types.current = 'morphTo';
       }
 
-      if (types.current === 'modelD' && types.other === 'model') {
+      if (types.current === 'morphTo') {
+        return {
+          nature: 'morphTo',
+          verbose: 'morphTo'
+        };
+      } else if (types.current === 'modelD' && types.other === 'morphTo') {
+        return {
+          nature: 'oneToOne',
+          verbose: 'morphOne'
+        };
+      } else if (types.current === 'collection' && types.other === 'morphTo') {
+        return {
+          nature: 'oneToMany',
+          verbose: 'morphMany'
+        };
+      } else if (types.current === 'modelD' && types.other === 'model') {
         return {
           nature: 'oneToOne',
           verbose: 'belongsTo'