feat(json-schema): add support for adding custom labels to enum (#1802)

demo/src/app/examples/advanced/json-schema/app.component.ts

@@ -26,6 +26,7 @@ export class AppComponent {
     'allOf',
     'null_field',
     'nullable',
+    'select_alternatives',
   ];
 
   constructor(

demo/src/app/examples/advanced/json-schema/config.module.ts

@@ -33,6 +33,7 @@ import { AppComponent } from './app.component';
               { file: 'assets/json-schema/allOf.json', content: require('!!highlight-loader?raw=true&lang=typescript!@assets/json-schema/allOf_json'), filecontent: require('!!raw-loader!@assets/json-schema/allOf_json') },
               { file: 'assets/json-schema/null_field.json', content: require('!!highlight-loader?raw=true&lang=typescript!@assets/json-schema/null_field_json'), filecontent: require('!!raw-loader!@assets/json-schema/null_field_json') },
               { file: 'assets/json-schema/nullable.json', content: require('!!highlight-loader?raw=true&lang=typescript!@assets/json-schema/nullable_json'), filecontent: require('!!raw-loader!@assets/json-schema/nullable_json') },
+              { file: 'assets/json-schema/select_alternatives.json', content: require('!!highlight-loader?raw=true&lang=typescript!@assets/json-schema/select_alternatives_json'), filecontent: require('!!raw-loader!@assets/json-schema/select_alternatives_json') },
             ],
           }],
         },

demo/src/assets/json-schema/select_alternatives_json

@@ -0,0 +1,99 @@
+{
+  "schema": {
+    "title": "Select alternatives",
+    "type": "object",
+    "properties": {
+      "select1": {
+        "type": "string",
+        "title": "Select 1: Enum array",
+        "enum": [
+          "Option 1",
+          "Option 2",
+          "Option 3"
+        ]
+      },
+      "select2": {
+        "type": "string",
+        "title": "Select 2: AnyOf/OneOf array with enum",
+        "anyOf": [
+          {
+            "title": "Option 1",
+            "enum": [
+              "option1"
+            ]
+          },
+          {
+            "title": "Option 2",
+            "enum": [
+              "option2"
+            ]
+          },
+          {
+            "title": "Option 3",
+            "enum": [
+              "option3"
+            ]
+          }
+        ]
+      },
+      "select3": {
+        "type": "string",
+        "title": "Select 3: AnyOf/OneOf array with const",
+        "oneOf": [
+          {
+            "title": "Option 1",
+            "const": "option1"
+          },
+          {
+            "title": "Option 2",
+            "const": "option2"
+          },
+          {
+            "title": "Option 3",
+            "const": "option3"
+          }
+        ]
+      },
+      "select4": {
+        "type": "string",
+        "title": "Select 4: Radio button",
+        "enum": [
+          "Option 1",
+          "Option 2",
+          "Option 3"
+        ],
+        "widget": {
+          "formlyConfig": {
+            "type": "radio"
+          }
+        }
+      },
+      "select5": {
+        "type": "string",
+        "title": "Select 5: with widget attr",
+        "widget": {
+          "formlyConfig": {
+            "type": "enum",
+            "templateOptions": {
+              "options": [
+                {
+                  "value": "1",
+                  "label": "option 1"
+                },
+                {
+                  "value": "2",
+                  "label": "option 2"
+                },
+                {
+                  "value": "3",
+                  "label": "option 3"
+                }
+              ]
+            }
+          }
+        }
+      }
+    }
+  },
+  "model": {}
+}

src/core/json-schema/src/formly-json-schema.service.spec.ts

@@ -487,15 +487,44 @@ describe('Service: FormlyJsonschema', () => {
 
       });
 
-      // TODO: add support for adding custom labels to enum values using oneOf/const
       // https://github.com/json-schema-org/json-schema-spec/issues/57#issuecomment-247861695
-      // it('should support enum as oneOf structure', () => {
-      //   const schema: JSONSchema7 = {
-      //     type: 'number',
-      //   };
+      describe('enum as oneOf/anyOf structure', () => {
+        it('should support enum as oneOf/const structure', () => {
+          const schema: JSONSchema7 = {
+            type: 'number',
+            oneOf: [{ title: '1', const: 1 }, { title: '2', const: 2 }],
+          };
 
-      //   const config = formlyJsonschema.toFieldConfig(schema);
-      // });
+          const { type, templateOptions: { options } } = formlyJsonschema.toFieldConfig(schema);
+
+          expect(type).toEqual('enum');
+          expect(options).toEqual([{ label: '1', value: 1 }, { label: '2', value: 2 }]);
+        });
+
+        it('should support enum as oneOf/enum structure', () => {
+          const schema: JSONSchema7 = {
+            type: 'number',
+            oneOf: [{ title: '1', enum: [1] }, { title: '2', enum: [2] }],
+          };
+
+          const { type, templateOptions: { options } } = formlyJsonschema.toFieldConfig(schema);
+
+          expect(type).toEqual('enum');
+          expect(options).toEqual([{ label: '1', value: 1 }, { label: '2', value: 2 }]);
+        });
+
+        it('should support enum as anyOf structure', () => {
+          const schema: JSONSchema7 = {
+            type: 'number',
+            anyOf: [{ title: '1', enum: [1] }, { title: '2', enum: [2] }],
+          };
+
+          const { type, templateOptions: { options } } = formlyJsonschema.toFieldConfig(schema);
+
+          expect(type).toEqual('enum');
+          expect(options).toEqual([{ label: '1', value: 1 }, { label: '2', value: 2 }]);
+        });
+      });
 
       // TODO: discuss const support possibly as hidden, already set field
       // it('should support cosnt', () => {

src/core/json-schema/src/formly-json-schema.service.ts

@@ -145,9 +145,9 @@ export class FormlyJsonschema {
       }
     }
 
-    if (schema.enum) {
+    if (this.isEnum(schema)) {
       field.type = 'enum';
-      field.templateOptions.options = schema.enum.map(value => ({ value, label: value }));
+      field.templateOptions.options = this.toEnumOptions(schema);
     }
 
     // map in possible formlyConfig options from the widget property
@@ -285,4 +285,34 @@ export class FormlyJsonschema {
     field.validators = field.validators || {};
     field.validators[name] = validator;
   }
+
+  private isEnum(schema: JSONSchema7) {
+    const isConst = (s: JSONSchema7) => s.hasOwnProperty('const') || (s.enum && s.enum.length === 1);
+
+    return schema.enum
+      || (schema.anyOf && schema.anyOf.every(isConst))
+      || (schema.oneOf && schema.oneOf.every(isConst));
+  }
+
+  private toEnumOptions(schema: JSONSchema7) {
+    if (schema.enum) {
+      return schema.enum.map(value => ({ value, label: value }));
+    }
+
+    const toEnum = (s: JSONSchema7) => {
+      const value = s.hasOwnProperty('const') ? s.const : s.enum[0];
+
+      return { value: value, label: s.title || value };
+    };
+
+    if (schema.anyOf) {
+      return schema.anyOf.map(toEnum);
+    }
+
+    if (schema.oneOf) {
+      return schema.oneOf.map(toEnum);
+    }
+
+    return [];
+  }
 }