Centralize configure-able factory classes

src/orm/model/TreeModel.ts

@@ -3,6 +3,7 @@ import {collect, Collection, ErrorWithContext, Maybe} from '../../util'
 import {HasSubtree} from './relation/HasSubtree'
 import {Related} from './relation/decorators'
 import {HasTreeParent} from './relation/HasTreeParent'
+import {ModelBuilder} from './ModelBuilder'
 
 /**
  * Model implementation with helpers for querying tree-structured data.
@@ -44,6 +45,12 @@ export abstract class TreeModel<T extends TreeModel<T>> extends Model<T> {
 
     public static readonly parentIdField = 'parent_id'
 
+    /** @override to include the tree fields */
+    public static query<T2 extends Model<T2>>(): ModelBuilder<T2> {
+        return super.query<T2>()
+            .fields(this.rightTreeField, this.leftTreeField, this.parentIdField)
+    }
+
     /**
      * @override to eager-load the subtree by default
      * @protected
@@ -52,6 +59,13 @@ export abstract class TreeModel<T extends TreeModel<T>> extends Model<T> {
 
     protected removedChildren: Collection<TreeModel<T>> = collect()
 
+    /** @override to include the tree fields */
+    public query(): ModelBuilder<T> {
+        const ctor = this.constructor as typeof TreeModel
+        return super.query()
+            .fields(ctor.leftTreeField, ctor.rightTreeField, ctor.parentIdField)
+    }
+
     /** Get the left tree number for this model. */
     public leftTreeNum(): Maybe<number> {
         const ctor = this.constructor as typeof TreeModel