Chromestatus Adding A Field

The FeaturesAPI uses api/api_specs.py to map request fields to database properties and handle types.

# api/api_specs.py

FEATURE_FIELD_DATA_TYPES: FIELD_INFO_DATA_TYPE = [
  # ...
  ('my_new_field', 'str'),  # 'str', 'int', 'bool', 'link', 'emails', etc.
]

Update Converters (Optional)

If your field needs custom formatting for the JSON response (e.g., date to string), update api/converters.py. Most simple types are handled automatically by to_dict.

# api/converters.py

def feature_entry_to_json_verbose(fe: FeatureEntry, ...):
    # ...
    d: VerboseFeatureDict = {
        # ...
        'my_new_field': fe.my_new_field,
    }

3. OpenAPI Specification

Update openapi/api.yaml if you want the field to be part of the official API documentation and generated models.

# openapi/api.yaml
# (Find the relevant schema, e.g., Feature or FeatureEntry if exists, 
# or update the endpoint response descriptions)

4. Frontend Layer

Define Form Field Metadata

Add the field's metadata (label, help text, component type) in client-src/elements/form-field-specs.ts.

// client-src/elements/form-field-specs.ts

export const ALL_FIELDS: Record<string, Field> = {
  // ...
  my_new_field: {
    type: 'input', // 'textarea', 'checkbox', 'select', etc.
    attrs: TEXT_FIELD_ATTRS,
    label: 'My New Field',
    usage: ALL_INTENT_USAGE_BY_FEATURE_TYPE,
    help_text: html`Explain what this field is for.`,
  },
};

Add to Form Definitions

Include the field in the relevant forms in client-src/elements/form-definition.ts.

// client-src/elements/form-definition.ts

export const FLAT_METADATA_FIELDS: MetadataFields = {
  name: 'Feature metadata',
  sections: [
    {
      name: 'Feature metadata',
      fields: [
        // ...
        'my_new_field',
      ],
    },
  ],
};

5. Verification

1. Backend: Run npm test to ensure NDB properties and converters work.
2. Frontend: Run npm run webtest or manually verify the new field appears in the feature edit form.
3. API: Manually check /api/v0/features/{id} to see if the field is present.