Merge ad21b69 into c1cff12

docs/site/BelongsTo-relation.md

@@ -43,6 +43,11 @@ related routes, you need to perform the following steps:
 This section describes how to define a `belongsTo` relation at the model level
 using the `@belongsTo` decorator to define the constraining foreign key.
 
+LB4 also provides an CLI tool `lb4 relation` to generate `belongsTo` relation
+for you. Before you check out the
+[`Relation Generator`](https://loopback.io/doc/en/lb4/Relation-generator.html)
+page, read on to learn how you can define relations to meet your requirements.
+
 ### Relation Metadata
 
 LB4 uses three `keyFrom`, `keyTo` and `name` fields in the `belongsTo` relation

docs/site/HasMany-relation.md

@@ -181,6 +181,11 @@ export interface OrderRelations {
 export type OrderWithRelations = Order & OrderRelations;
 ```
 
+LB4 also provides an CLI tool `lb4 relation` to generate `hasMany` relation for
+you. Before you check out the
+[`Relation Generator`](https://loopback.io/doc/en/lb4/Relation-generator.html)
+page, read on to learn how you can define relations to meet your requirements.
+
 ### Relation Metadata
 
 LB4 uses three `keyFrom`, `keyTo` and `name` fields in the `hasMany` relation

docs/site/Relation-generator.md

@@ -32,7 +32,8 @@ lb4 relation [options]
 - `--relationType`: Relation type.
 - `--sourceModel`: Source model.
 - `--destinationModel`: Destination model.
-- `--foreignKeyName`: Destination model foreign key name.
+- `--foreignKeyName`: Destination/Source model foreign key name for
+  HasMany/BelongsTo relation, respectively.
 - `--relationName`: Relation name.
 - `-c`, `--config`: JSON file name or value to configure options.
 - `-y`, `--yes`: Skip all confirmation prompts with default or provided value.
@@ -88,18 +89,31 @@ The tool will prompt you for:
 - **Name of the `target` model.** _(targetModel)_ Prompts a list of available
   models to choose from as the target model of the relation.
 
-- **Name of the `Source property`.** _(relationName)_ Prompts for the Source
-  property name. Note: Leave blank to use the default.
+- **Name of the `foreign key`.** _(relationName)_ Prompts a property name that
+  references the primary key property of the another model. Note: Leave blank to
+  use the default.
+
+  Default values: `<foreignKeyName>` + `Id` in camelCase, e.g `categoryId`
+
+- **Name of the `relation`.** _(relationName)_ Prompts for the Source property
+  name. Note: Leave blank to use the default.
 
   Default values:
 
-  - `<targetModel><targetModelPrimaryKey>` for `belongsTo` relations, e.g.
-    `categoryId`
   - plural form of `<targetModel>` for `hasMany` relations, e.g. `products`
-
-- **Name of Foreign key** _(foreignKeyName)_ to be created in target model. For
-  hasMany relation type only, default: `<sourceModel><sourceModelPrimaryKey>`.
-  Note: Leave blank to use the default.
+  - Based on the foreign key for `belongsTo` relations, e.g. when the foreign
+    key is the default name, e.g `categoryId`, the default relation name is
+    `category`.
+
+{% include warning.html content="Based on your input, the default foreign key name might be the same as the default relation name, especially for belongsTo relation. Please name them differently to avoid a known issue [Navigational Property Error](https://github.com/strongloop/loopback-next/issues/4392)
+" lang=page.lang %}
+
+The generator has some limitations. It only asks the most basic factors for
+generating relations. For example, it uses the id property as the source key.
+LB4 allows you customize the source key name, the foreign key name, the relation
+name, and even the DB column name. Check the
+[Relation Metadata](HasMany-relation.md#relation-metadata) section in each
+relation to learn how you can define relations.
 
 ### Output
 

packages/cli/generators/relation/base-relation.generator.js

@@ -39,12 +39,12 @@ module.exports = class BaseRelationGenerator extends ArtifactGenerator {
   }
 
   async generateAll(options) {
-    this._setupGenerator();
-    await this.generateControllers(options);
     this._setupGenerator();
     await this.generateModels(options);
     this._setupGenerator();
     await this.generateRepositories(options);
+    this._setupGenerator();
+    await this.generateControllers(options);
   }
 
   async generateControllers(options) {
@@ -98,23 +98,17 @@ module.exports = class BaseRelationGenerator extends ArtifactGenerator {
       type: this._getRepositoryRelationPropertyType(),
     };
 
-    if (relationUtils.doesPropertyExist(classDeclaration, property.name)) {
-      throw new Error(
-        'property ' + property.name + ' already exist in the repository.',
-      );
-    } else {
-      relationUtils.addProperty(classDeclaration, property);
-    }
+    // already chcked the existence of property before
+    relationUtils.addProperty(classDeclaration, property);
   }
 
   _addParametersToRepositoryConstructor(classConstructor) {
     const parameterName =
       utils.camelCase(this.artifactInfo.dstRepositoryClassName) + 'Getter';
 
     if (relationUtils.doesParameterExist(classConstructor, parameterName)) {
-      throw new Error(
-        'Parameter ' + parameterName + ' already exist in the constructor.',
-      );
+      // no need to check if the getter already exists
+      return;
     }
 
     classConstructor.addParameter({

packages/cli/generators/relation/belongs-to-relation.generator.js

@@ -73,12 +73,16 @@ module.exports = class BelongsToRelationGenerator extends BaseRelationGenerator
   }
 
   async generateModels(options) {
+    // for repo to generate relation name
+    this.artifactInfo.relationName = options.relationName;
     const modelDir = this.artifactInfo.modelDir;
     const sourceModel = options.sourceModel;
 
     const targetModel = options.destinationModel;
     const relationType = options.relationType;
     const relationName = options.relationName;
+    const defaultRelationName = options.defaultRelationName;
+    const foreignKeyName = options.foreignKeyName;
     const fktype = options.destinationModelPrimaryKeyType;
 
     const project = new relationUtils.AstLoopBackProject();
@@ -88,10 +92,16 @@ module.exports = class BelongsToRelationGenerator extends BaseRelationGenerator
       sourceModel,
     );
     const sourceClass = relationUtils.getClassObj(sourceFile, sourceModel);
-
-    relationUtils.doesRelationExist(sourceClass, relationName);
-
-    const modelProperty = this.getBelongsTo(targetModel, relationName, fktype);
+    // this checks if the foreign key already exists, so the 2nd param should be foreignKeyName
+    relationUtils.doesRelationExist(sourceClass, foreignKeyName);
+
+    const modelProperty = this.getBelongsTo(
+      targetModel,
+      relationName,
+      defaultRelationName,
+      foreignKeyName,
+      fktype,
+    );
 
     relationUtils.addProperty(sourceClass, modelProperty);
     const imports = relationUtils.getRequiredImports(targetModel, relationType);
@@ -101,10 +111,32 @@ module.exports = class BelongsToRelationGenerator extends BaseRelationGenerator
     await sourceFile.save();
   }
 
-  getBelongsTo(className, relationName, fktype) {
+  getBelongsTo(
+    className,
+    relationName,
+    defaultRelationName,
+    foreignKeyName,
+    fktype,
+  ) {
+    // checks if relation name is customized
+    let relationDecorator = [
+      {
+        name: 'belongsTo',
+        arguments: [`() =>  ${className}`],
+      },
+    ];
+    // already checked if the relation name is the same as the source key before
+    if (defaultRelationName !== relationName) {
+      relationDecorator = [
+        {
+          name: 'belongsTo',
+          arguments: [`() =>  ${className}, {name: '${relationName}'}`],
+        },
+      ];
+    }
     return {
-      decorators: [{name: 'belongsTo', arguments: [`() =>  ${className}`]}],
-      name: relationName,
+      decorators: relationDecorator,
+      name: foreignKeyName,
       type: fktype,
     };
   }
@@ -122,7 +154,7 @@ module.exports = class BelongsToRelationGenerator extends BaseRelationGenerator
   }
 
   _getRepositoryRelationPropertyName() {
-    return utils.camelCase(this.artifactInfo.dstModelClass);
+    return this.artifactInfo.relationName;
   }
 
   _initializeProperties(options) {
@@ -140,22 +172,22 @@ module.exports = class BelongsToRelationGenerator extends BaseRelationGenerator
   }
 
   _addCreatorToRepositoryConstructor(classConstructor) {
-    const relationPropertyName = this._getRepositoryRelationPropertyName();
+    const relationName = this.artifactInfo.relationName;
     const statement =
-      `this.${relationPropertyName} = ` +
+      `this.${relationName} = ` +
       `this.createBelongsToAccessorFor('` +
-      `${this.artifactInfo.relationName.replace(/Id$/, '')}',` +
+      `${relationName}',` +
       ` ${utils.camelCase(this.artifactInfo.dstRepositoryClassName)}` +
       `Getter,);`;
     classConstructor.insertStatements(1, statement);
   }
 
   _registerInclusionResolverForRelation(classConstructor, options) {
-    const relationPropertyName = this._getRepositoryRelationPropertyName();
+    const relationName = this.artifactInfo.relationName;
     if (options.registerInclusionResolver) {
       const statement =
         `this.registerInclusionResolver(` +
-        `'${relationPropertyName}', this.${relationPropertyName}.inclusionResolver);`;
+        `'${relationName}', this.${relationName}.inclusionResolver);`;
       classConstructor.insertStatements(2, statement);
     }
   }

packages/cli/generators/relation/has-many-relation.generator.js

@@ -74,6 +74,8 @@ module.exports = class HasManyRelationGenerator extends BaseRelationGenerator {
   }
 
   async generateModels(options) {
+    // for repo to generate relation name
+    this.artifactInfo.relationName = options.relationName;
     const modelDir = this.artifactInfo.modelDir;
     const sourceModel = options.sourceModel;
 
@@ -166,7 +168,7 @@ module.exports = class HasManyRelationGenerator extends BaseRelationGenerator {
   }
 
   _getRepositoryRelationPropertyName() {
-    return utils.pluralize(utils.camelCase(this.artifactInfo.dstModelClass));
+    return this.artifactInfo.relationName;
   }
 
   _getRepositoryRelationPropertyType() {