Context: As a user, I want to scope a table's records based on the value of an attribute nested within a json column.

Example: I have a table users that includes a JSONB column named contact. The contact json can include a phone, email or country attribute. Since I want to scope my collection by country, I created a smart field called country that returns the value of the country attribute and I implemented a filter feature for this field.

Implementation

The smart field definition and the filtering logic are defined as follows in the forest/users.js file of my admin backend.

const { collection } = require('forest-express-sequelize');
const models = require('../models');

const { Op } = models.objectMapping;

collection('users', {
  actions: [],
  fields: [{
    field: 'country',
    isFilterable: true,
    type: 'String',
    get: (record) => record.contact.country,
    filter({ condition, where }) {
      switch (condition.operator) {
        case 'equal':
          return {
            'contact.country': { [Op.eq]: condition.value },
          };
          // ... And so on with the other operators not_equal, starts_with, etc.

        default:
          return null;
      }
    },
  }],
  segments: [],
});

<aside> ⚠️ In order to make your smart field filterable in the UI, you both need to add the isFilterable: true option in the field's declaration and to enable filtering on this field in the field settings in the UI.

</aside>