feat(cli): add option to create relations in cli discover command

docs/site/Discovering-models.md

@@ -39,6 +39,8 @@ Models can be discovered from a supported datasource by running the
 
 `--views`: Choose whether to discover views. Default is true
 
+`--relations`: Choose whether to create relations. Default is false
+
 `--all`: Skips the model prompt and discovers all of them
 
 `--outDir`: Specify the directory into which the `model.model.ts` files will be

packages/cli/.yo-rc.json

@@ -1251,6 +1251,13 @@
           "name": "views",
           "hide": false
         },
+        "relations": {
+          "type": "Boolean",
+          "description": "Discover and create relations",
+          "default": false,
+          "name": "relations",
+          "hide": false
+        },
         "schema": {
           "type": "String",
           "description": "Schema to discover",

packages/cli/generators/discover/index.js

@@ -31,6 +31,12 @@ module.exports = class DiscoveryGenerator extends ArtifactGenerator {
       default: true,
     });
 
+    this.option('relations', {
+      type: Boolean,
+      description: g.f('Discover and create relations'),
+      default: false,
+    });
+
     this.option('schema', {
       type: String,
       description: g.f('Schema to discover'),
@@ -289,6 +295,7 @@ module.exports = class DiscoveryGenerator extends ArtifactGenerator {
         {
           schema: modelInfo.owner,
           disableCamelCase: this.artifactInfo.disableCamelCase,
+          associations: this.options.relations,
         },
       );
       if (this.options.optionalId) {
@@ -336,6 +343,46 @@ module.exports = class DiscoveryGenerator extends ArtifactGenerator {
       );
       debug(`Writing: ${fullPath}`);
 
+      if (this.options.relations) {
+        const relationImports = [];
+        const relationDestinationImports = [];
+        const foreignKeys = {};
+        for (const relationName in templateData.settings.relations) {
+          const relation = templateData.settings.relations[relationName];
+          const targetModel = this.artifactInfo.modelDefinitions.find(
+            model => model.name === relation.model,
+          );
+          // If targetModel is not in discovered models, skip creating relation
+          if (targetModel) {
+            Object.assign(templateData.properties[relation.foreignKey], {
+              relation,
+            });
+            relationImports.push(relation.type);
+            relationDestinationImports.push(relation.model);
+
+            foreignKeys[relationName] = {};
+            Object.assign(foreignKeys[relationName], {
+              name: relationName,
+              entity: relation.model,
+              entityKey: Object.entries(targetModel.properties).find(
+                x => x?.[1].id === 1,
+              )?.[0],
+              foreignKey: relation.foreignKey,
+            });
+          }
+        }
+        templateData.relationImports = relationImports;
+        templateData.relationDestinationImports = relationDestinationImports;
+        // Delete relation from modelSettings
+        delete templateData.settings.relations;
+        if (Object.keys(foreignKeys)?.length > 0) {
+          Object.assign(templateData.settings, {foreignKeys});
+        }
+        templateData.modelSettings = utils.stringifyModelSettings(
+          templateData.settings,
+        );
+      }
+
       this.copyTemplatedFiles(
         modelDiscoverer.MODEL_TEMPLATE_PATH,
         fullPath,

packages/cli/generators/model/templates/model.ts.ejs

@@ -1,9 +1,12 @@
 <% if (isModelBaseBuiltin) { -%>
-import {<%= modelBaseClass %>, model, property} from '@loopback/repository';
+import {<%= modelBaseClass %>, model, property<%if (locals.relationImports) {%><% relationImports.forEach((relation) => {-%>, <%= relation %> <%_})-%><%}%>} from '@loopback/repository';
 <% } else { -%>
-import {model, property} from '@loopback/repository';
+import {model, property<%if (locals.relationImports) {%><% relationImports.forEach((relation) => {-%> , <%= relation %> <%_})-%><%}%>} from '@loopback/repository';
 import {<%= modelBaseClass %>} from '.';
 <% } -%>
+<%_ if (locals.relationDestinationImports && locals.relationDestinationImports.length > 0) { -%>
+import {<% relationDestinationImports.forEach((model, index) => {-%><%= model %><%if (index!==relationDestinationImports.length-1) {%>,<% } %> <%_}) -%>} from '.';
+<%_ } -%>
 
 <% if (modelSettings) { -%>
 @model(<%- modelSettings %>)
@@ -12,13 +15,17 @@ import {<%= modelBaseClass %>} from '.';
 <% } -%>
 export class <%= className %> extends <%= modelBaseClass %> {
 <% Object.entries(properties).forEach(([key, val]) => { -%>
+<% if (val.relation) { -%>
+  @<%= val.relation.type %>(() => <%= val.relation.model %>)
+<% } else { -%>
   @property({
   <%_ Object.entries(val).forEach(([propKey, propVal]) => { -%>
-    <%_ if (!['tsType'].includes(propKey)) { -%>
+  <%_ if (!['tsType', 'relation'].includes(propKey)) { -%>
     <%= propKey %>: <%- propVal %>,
-    <%_ } -%>
+  <%_ } -%>
   <%_ }) -%>
   })
+<% } -%>
   <%= key %><%if (!val.required) {%>?<% } %>: <%= val.tsType %>;
 
 <% }) -%>

packages/cli/snapshots/integration/cli/cli.integration.snapshots.js

@@ -1309,6 +1309,13 @@ exports[`cli saves command metadata to .yo-rc.json 1`] = `
           "name": "views",
           "hide": false
         },
+        "relations": {
+          "type": "Boolean",
+          "description": "Discover and create relations",
+          "default": false,
+          "name": "relations",
+          "hide": false
+        },
         "schema": {
           "type": "String",
           "description": "Schema to discover",