Implemented foreign key depth traversal feature. Allows you to set a …

…limit to how deep foreign key instance retrieval goes
MKHenson · May 23, 2016 · 6128276 · 6128276
1 parent 93ff59c
commit 6128276
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Showing 4 changed files with 51 additions and 1 deletion.
diff --git a/server/dist/definitions/modepress-api.d.ts b/server/dist/definitions/modepress-api.d.ts
@@ -26,6 +26,14 @@ declare module Modepress
          * If true, then all data is returned and is not stripped of sensitive items
          */
         verbose : boolean
+
+        /**
+         * Defines how many levels deep foreign key traversal iterates. If 1, then only the immediate foreign keys
+         * are fetched. For example  Model X references model Y, which in turn references another model X. When expandMaxDepth=1
+         * only model X and its model Y instance are returned (Model Y's reference to any X is ignored)
+         * Only read if expandForeignKeys is true.
+         */
+        expandMaxDepth? : number;
     }
 
     /*

diff --git a/server/dist/src/models/schema-items/schema-foreign-key.js b/server/dist/src/models/schema-items/schema-foreign-key.js
@@ -29,6 +29,7 @@ class SchemaForeignKey extends schema_item_1.SchemaItem {
         super(name, val);
         this.targetCollection = targetCollection;
         this.optionalKey = optionalKey;
+        this.curLevel = 1;
     }
     /**
     * Creates a clone of this item
@@ -122,7 +123,20 @@ class SchemaForeignKey extends schema_item_1.SchemaItem {
                 if (model) {
                     if (!this.value)
                         return null;
+                    // Make sure the current level is not beyond the max depth
+                    if (options.expandMaxDepth !== undefined) {
+                        if (this.curLevel > options.expandMaxDepth)
+                            return this.value;
+                    }
+                    else
+                        options.expandMaxDepth = 1;
                     var result = yield model.findOne({ _id: this.value });
+                    // Get the models items are increase their level - this ensures we dont go too deep
+                    var items = result.schema.getItems();
+                    var nextLevel = this.curLevel + 1;
+                    for (var i = 0, l = items.length; i < l; i++)
+                        if (items[i] instanceof SchemaForeignKey)
+                            items[i].curLevel = nextLevel;
                     return yield result.schema.getAsJson(result.dbEntry._id, options);
                 }
                 else

diff --git a/server/src/definitions/custom/modepress-api.d.ts b/server/src/definitions/custom/modepress-api.d.ts
@@ -26,6 +26,14 @@
          * If true, then all data is returned and is not stripped of sensitive items
          */
         verbose : boolean
+
+        /**
+         * Defines how many levels deep foreign key traversal iterates. If 1, then only the immediate foreign keys
+         * are fetched. For example  Model X references model Y, which in turn references another model X. When expandMaxDepth=1
+         * only model X and its model Y instance are returned (Model Y's reference to any X is ignored)
+         * Only read if expandForeignKeys is true.
+         */
+        expandMaxDepth? : number;
     }
 
     /*

diff --git a/server/src/models/schema-items/schema-foreign-key.ts b/server/src/models/schema-items/schema-foreign-key.ts
@@ -14,6 +14,7 @@ export class SchemaForeignKey extends SchemaItem<ObjectID | string | Modepress.I
 {
     public targetCollection : string;
     public optionalKey : boolean;
+    public curLevel: number;
 
     private _targetDoc : ModelInstance<Modepress.IModelEntry>;
 
@@ -29,6 +30,7 @@ export class SchemaForeignKey extends SchemaItem<ObjectID | string | Modepress.I
         super(name, val);
         this.targetCollection = targetCollection;
         this.optionalKey = optionalKey;
+        this.curLevel = 1;
     }
 
 	/**
@@ -147,8 +149,26 @@ export class SchemaForeignKey extends SchemaItem<ObjectID | string | Modepress.I
                 if (!this.value)
                     return null;
 
+                // Make sure the current level is not beyond the max depth
+                if (options.expandMaxDepth !== undefined)
+                {
+                    if ( this.curLevel > options.expandMaxDepth )
+                        return this.value;
+                }
+                else
+                    options.expandMaxDepth = 1;
+
                 var result = await model.findOne<Modepress.IModelEntry>( { _id : <ObjectID>this.value } );
-                return await result.schema.getAsJson<Modepress.IModelEntry>( result.dbEntry._id, options);
+
+                // Get the models items are increase their level - this ensures we dont go too deep
+                var items = result.schema.getItems();
+                var nextLevel = this.curLevel + 1;
+
+                for (var i = 0, l = items.length; i < l; i++)
+                    if ( items[i] instanceof SchemaForeignKey )
+                        (<SchemaForeignKey>items[i]).curLevel = nextLevel;
+
+                return await result.schema.getAsJson<Modepress.IModelEntry>( result.dbEntry._id, options );
             }
             else
                 throw new Error(`${this.name} references a foreign key '${this.targetCollection}' which doesn't seem to exist`);