feat(cli): add lb4 relation command

docs/site/Relation-generator.md

@@ -0,0 +1,109 @@
+---
+lang: en
+title: 'Relation generator'
+keywords: LoopBack 4.0, LoopBack 4
+sidebar: lb4_sidebar
+permalink: /doc/en/lb4/Relation-generator.html
+---
+
+### Prerequisites
+
+Important: Before running this generator, make sure the models, datasource, and
+repositories involved in this relation exist. Then, inside your LoopBack
+application, run the command from the root directory.
+
+{% include content/generator-create-app.html lang=page.lang %}
+
+### Synopsis
+
+Adds a new `Relation` between existing source and target models in a LoopBack
+application.
+
+```sh
+lb4 relation [options]
+```
+
+### Options
+
+- `-h`, `--help`: Print the generator’s options and usage.
+- `--skip-cache`: Do not remember prompt answers. Default: `false`.
+- `--skip-install`: Do not automatically install dependencies. Default: `false`.
+- `--force-install`: Fail on install dependencies error. Default: `false`.
+- `--relationType`: Relation type.
+- `--sourceModel`: Source model.
+- `--destinationModel`: Destination model.
+- `--foreignKeyName`: Destination model foreign key name.
+- `--relationName`: Relation name.
+- `-c`, `--config`: JSON file name or value to configure options.
+- `-y`, `--yes`: Skip all confirmation prompts with default or provided value.
+- `--format`: Format generated code using `npm run lint:fix`.
+
+### Arguments
+
+Defining lb4 relation in one command line interface (cli):
+
+```sh
+lb4 relation --sourceModel=<sourceModel>
+--destinationModel=<destinationModel> --foreignKeyName=<foreignKeyName>
+--relationType=<hasMany|belongsTo> [--relationName=<relationName>] [--format]
+```
+
+- `<relationType>` - Type of the relation that will be created between the
+  source and target models.
+
+- `<sourceModel>` - Name of the model to create the relationship from.
+
+- `<destinationModel>` - Name of the model to create a relationship with.
+
+- `<foreignKeyName>` - Property that references the primary key property of the
+  destination model.
+
+- `<relationName>` - Name of the relation that will be created.
+
+### Interactive Prompts
+
+The tool will prompt you for:
+
+- **Relation `type` between models.** _(relationBaseClass)_ Prompts a list of
+  available relations to choose from as the type of the relation between the
+  source model and the target model. Supported relation types:
+
+  - [HasMany](HasMany-relation.md)
+  - [BelongsTo](BelongsTo-relation.md)
+
+- **Name of the `source` model.** _(sourceModel)_ Prompts a list of available
+  models to choose from as the source model of the relation.
+
+- **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.
+
+  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.
+
+### Output
+
+Once all the prompts have been answered, the CLI will update or create source
+files for the Entities involved in the relation.
+
+- Update source Model class as follows:
+  `/src/models/${sourceModel-Name}.model.ts`
+- Update target Model class as follows:
+  `/src/models/${targetModel-Name}.model.ts`
+- Update source Model Repository class as follows:
+  `/src/repositories/${sourceModel-Repository-Name}.repository.ts`
+- Update target Model Repository class as follows:
+  `/src/repositories/${targetModel-Repository-Name}.repository.ts`
+- Create a Controller for the new relation as follows:
+  `/src/controllers/{sourceModel-Name}-{targetModel-Name}.controller.ts`
+- Update `/src/controllers/index.ts` to export the newly created Controller
+  class.

packages/cli/README.md

@@ -304,7 +304,33 @@ Run the following command to install the CLI.
       name  # Name for the discover  Type: String  Required: false
     ```
 
-12. To list available commands
+12. To generate relation into your application
+
+    ```sh
+    cd <your-project-directory>
+    lb4 relation
+    ```
+
+    ```sh
+    Usage:
+      lb4 relation [options]
+
+    Options:
+      -h,   --help              # Print the generator's options and usage
+            --skip-cache        # Do not remember prompt answers                                Default: false
+            --skip-install      # Do not automatically install dependencies                     Default: false
+            --force-install     # Fail on install dependencies error                            Default: false
+            --relationType      # Relation type
+            --sourceModel       # Source model
+            --destinationModel  # Destination model
+            --foreignKeyName    # Destination model foreign key name
+            --relationName      # Relation name
+      -c,   --config            # JSON file name or value to configure options
+      -y,   --yes               # Skip all confirmation prompts with default or provided value
+            --format            # Format generated code using npm run lint:fix
+    ```
+
+13. To list available commands
 
     `lb4 --commands` (or `lb4 -l`)
 
@@ -319,11 +345,12 @@ Run the following command to install the CLI.
       lb4 service
       lb4 example
       lb4 openapi
+      lb4 relation
     ```
 
     Please note `lb4 --help` also prints out available commands.
 
-13. To print out version information
+14. To print out version information
 
     `lb4 --version` (or `lb4 -v`)
 

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

@@ -0,0 +1,209 @@
+// Copyright IBM Corp. 2019. All Rights Reserved.
+// Node module: @loopback/cli
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+'use strict';
+
+const ast = require('ts-morph');
+const ArtifactGenerator = require('../../lib/artifact-generator');
+const path = require('path');
+const relationUtils = require('./utils.generator');
+const utils = require('../../lib/utils');
+
+module.exports = class BaseRelationGenerator extends ArtifactGenerator {
+  constructor(args, opts) {
+    super(args, opts);
+  }
+
+  _setupGenerator() {
+    this.artifactInfo = {
+      type: 'relation',
+      rootDir: utils.sourceRootDir,
+    };
+
+    this.artifactInfo.outDir = path.resolve(
+      this.artifactInfo.rootDir,
+      'controllers',
+    );
+    this.artifactInfo.modelDir = path.resolve(
+      this.artifactInfo.rootDir,
+      'models',
+    );
+    this.artifactInfo.repositoryDir = path.resolve(
+      this.artifactInfo.rootDir,
+      'repositories',
+    );
+
+    super._setupGenerator();
+  }
+
+  async generateAll(options) {
+    this._setupGenerator();
+    await this.generateControllers(options);
+    this._setupGenerator();
+    await this.generateModels(options);
+    this._setupGenerator();
+    await this.generateRepositories(options);
+  }
+
+  generateControllers(options) {
+    /* istanbul ignore next */
+    throw new Error('Not implemented');
+  }
+
+  generateModels(options) {
+    /* istanbul ignore next */
+    throw new Error('Not implemented');
+  }
+
+  async generateRepositories(options) {
+    this._initializeProperties(options);
+    this._addImportsToRepository(options);
+    this._addPropertyToRepository(options);
+    const classDeclaration = relationUtils.getClassObj(
+      this.artifactInfo.srcRepositoryFileObj,
+      this.artifactInfo.srcRepositoryClassName,
+    );
+    const classConstructor = relationUtils.getClassConstructor(
+      classDeclaration,
+    );
+    this._addParametersToRepositoryConstructor(classConstructor);
+    this._addCreatorToRepositoryConstructor(classConstructor);
+    await this.artifactInfo.srcRepositoryFileObj.save();
+  }
+
+  _addImportsToRepository(options) {
+    const imports = this._getRepositoryRequiredImports(
+      options.destinationModel,
+      this.artifactInfo.dstRepositoryClassName,
+    );
+
+    relationUtils.addRequiredImports(
+      this.artifactInfo.srcRepositoryFileObj,
+      imports,
+    );
+  }
+
+  _addPropertyToRepository(options) {
+    const classDeclaration = this.artifactInfo.srcRepositoryFileObj.getClassOrThrow(
+      this.artifactInfo.srcRepositoryClassName,
+    );
+
+    const property = {
+      scope: ast.Scope.Public,
+      isReadonly: true,
+      name: this._getRepositoryRelationPropertyName(),
+      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);
+    }
+  }
+
+  _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.',
+      );
+    }
+
+    classConstructor.addParameter({
+      decorators: [
+        {
+          name: 'repository.getter',
+          arguments: ["'" + this.artifactInfo.dstRepositoryClassName + "'"],
+        },
+      ],
+      name: parameterName,
+      type: 'Getter<' + this.artifactInfo.dstRepositoryClassName + '>,',
+      scope: ast.Scope.Protected,
+    });
+  }
+
+  _addCreatorToRepositoryConstructor(classConstructor) {
+    /* istanbul ignore next */
+    throw new Error('Not implemented');
+  }
+
+  _initializeProperties(options) {
+    // src configuration.
+    this.artifactInfo.srcModelPrimaryKey = options.sourceModelPrimaryKey;
+    this.artifactInfo.srcModelFile = path.resolve(
+      this.artifactInfo.modelDir,
+      utils.getModelFileName(options.sourceModel),
+    );
+
+    this.artifactInfo.srcModelClass = options.sourceModel;
+
+    this.artifactInfo.srcRepositoryFile = path.resolve(
+      this.artifactInfo.repositoryDir,
+      utils.getRepositoryFileName(options.sourceModel),
+    );
+
+    this.artifactInfo.srcRepositoryClassName =
+      utils.toClassName(options.sourceModel) + 'Repository';
+
+    this.artifactInfo.srcRepositoryFileObj = new relationUtils.AstLoopBackProject().addExistingSourceFile(
+      this.artifactInfo.srcRepositoryFile,
+    );
+
+    // dst configuration
+    this.artifactInfo.dstModelFile = path.resolve(
+      this.artifactInfo.modelDir,
+      utils.getModelFileName(options.destinationModel),
+    );
+
+    this.artifactInfo.dstModelClass = options.destinationModel;
+
+    this.artifactInfo.dstRepositoryFile = path.resolve(
+      this.artifactInfo.repositoryDir,
+      utils.getRepositoryFileName(options.destinationModel),
+    );
+
+    this.artifactInfo.dstRepositoryClassName =
+      utils.toClassName(options.destinationModel) + 'Repository';
+
+    // relation configuration
+    this.artifactInfo.relationName = options.relationName;
+  }
+
+  _getRepositoryRequiredImports(dstModelClassName, dstRepositoryClassName) {
+    return [
+      {
+        name: dstModelClassName,
+        module: '../models',
+      },
+      {
+        name: 'repository',
+        module: '@loopback/repository',
+      },
+      {
+        name: 'Getter',
+        module: '@loopback/core',
+      },
+      {
+        name: dstRepositoryClassName,
+        module: `./${utils.kebabCase(dstModelClassName)}.repository`,
+      },
+    ];
+  }
+
+  _getRepositoryRelationPropertyName() {
+    /* istanbul ignore next */
+    throw new Error('Not implemented');
+  }
+
+  _getRepositoryRelationPropertyType() {
+    /* istanbul ignore next */
+    throw new Error('Not implemented');
+  }
+};