Smart Fields - Forest Documentation

What is a Smart Field?

A field that displays a computed value in your collection.

A Smart Field is a column that displays processed-on-the-fly data. It can be as simple as concatenating attributes to make them human friendly, or more complex (e.g. total of orders).

Creating a Smart Field

SQL
Mongoose
Rails
Django
Laravel

On our Live Demo, the very simple Smart Field fullname is available on the customers collection.

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

collection('customers', {
  fields: [
    {
      field: 'fullname',
      type: 'String',
      get: (customer) => {
        return customer.firstname + ' ' + customer.lastname;
      },
    },
  ],
});

Very often, the business logic behind the Smart Field is more complex and must be asynchronous. To do that, please have a look at this section.

On our Live Demo, the very simple Smart Field fullname is available on the customers collection.

const { collection } = require('forest-express-mongoose');

collection('customers', {
  fields: [
    {
      field: 'fullname',
      type: 'String',
      get: (customer) => {
        return customer.firstname + ' ' + customer.lastname;
      },
    },
  ],
});

Very often, the business logic behind the Smart Field is more complex and must be asynchronous. To do that, please have a look at this section.

On our Live Demo, the very simple Smart Field fullname is available on the Customer collection.

class Forest::Customer
  include ForestLiana::Collection

  collection :Customer

  field :fullname, type: 'String' do
    "#{object.firstname} #{object.lastname}"
  end
end

Very often, the business logic behind the Smart Field is more complex and must interact with the database. Here’s an example with the Smart Field full_address on the Customer collection.

class Forest::Customer
  include ForestLiana::Collection

  collection :Customer

  field :full_address, type: 'String' do
    address = Address.find_by(customer_id: object.id)
    "#{address[:address_line_1]} #{address[:address_line_2]} #{address[:address_city]} #{address[:country]}"
  end
end

On our Live Demo, the very simple Smart Field fullname is available on the Customer collection.Ensure the file app/forest/__init__.py exists and contains the import of the previous defined class :

On our Live Demo, the very simple Smart Field fullname is available on the Customer model.Very often, the business logic behind the Smart Field is more complex and must interact with the database. Here’s an example with the Smart Field full_address on the Customer model.

The collection name must be the same as the model name.

Updating a Smart Field

SQL
Mongoose
Rails
Django

By default, your Smart Field is considered as read-only. If you want to update a Smart Field, you just need to write the logic to “unzip” the data. Note that the set method should always return the object it’s working on. In the example hereunder, the customer object is returned including only the modified data.

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

collection('customers', {
  fields: [
    {
      field: 'fullname',
      type: 'String',
      get: (customer) => {
        return customer.firstname + ' ' + customer.lastname;
      },
      set: (customer, fullname) => {
        let names = fullname.split(' ');
        customer.firstname = names[0];
        customer.lastname = names[1];

        // Don't forget to return the customer.
        return customer;
      },
    },
  ],
});

Working with the actual record can be done this way:

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

collection('customers', {
  fields: [
    {
      field: 'fullname',
      type: 'String',
      get: (customer) => {
        return customer.firstname + ' ' + customer.lastname;
      },
      set: async (customer, fullname) => {
        const customerBeforeUpdate = await customers.findOne({
          where: { id: customer.id },
        });

        const names = fullname.split(' ');
        customer.firstname = `${names[0]} ${customerBeforeUpdate.pseudo}`;
        return customer;
      },
    },
  ],
});

For security reasons, the fullname Smart field will remain read-only, even after you implement the set method. To edit it, disable read-only mode in the field settings.

const { collection } = require('forest-express-mongoose');

collection('customers', {
  fields: [
    {
      field: 'fullname',
      type: 'String',
      get: (customer) => {
        return customer.firstname + ' ' + customer.lastname;
      },
      set: (customer, fullname) => {
        let names = fullname.split(' ');
        customer.firstname = names[0];
        customer.lastname = names[1];

        // Don't forget to return the customer.
        return customer;
      },
    },
  ],
});

Working with the actual record can be done this way:

const { collection, ResourceGetter } = require('forest-express-mongoose');
const { customers } = require('../models');

collection('customers', {
  fields: [
    {
      field: 'fullname',
      type: 'String',
      get: (customer) => {
        return customer.firstname + ' ' + customer.lastname;
      },
      set: async (customer, fullname) => {
        const customerBeforeUpdate = await customers.findById(customer.id);

        const names = fullname.split(' ');
        customer.firstname = `${names[0]} ${customerBeforeUpdate.pseudo}`;
        return customer;
      },
    },
  ],
});

For security reasons, the fullname Smart field will remain read-only, even after you implement the set method. To edit it, disable read-only mode in the field settings.

By default, your Smart Field is considered as read-only. If you want to update a Smart Field, you just need to write the logic to “unzip” the data. Note that the set method should always return the object it’s working on. In the example hereunder, the user_params is returned is returned including only the modified data.

class Forest::Customer
  include ForestLiana::Collection

  collection :Customer

  set_fullname = lambda do |user_params, fullname|
    fullname = fullname.split
    user_params[:firstname] = fullname.first
    user_params[:lastname] = fullname.last

    # Returns a hash of the updated values you want to persist.
    user_params
  end

  field :fullname, type: 'String', set: set_fullname do
    "#{object.firstname} #{object.lastname}"
  end
end

For security reasons, the fullname Smart field will remain read-only, even after you implement the set method. To edit it, disable read-only mode in the field settings.

Searching, Sorting and Filtering on a Smart Field

To perform a search on a Smart Field, you also need to write the logic to “unzip” the data, then the search query which is specific to your zipping. In the example hereunder, the firstname and lastname are searched separately after having been unzipped.

SQL
Mongoose
Rails

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

collection('customers', {
  fields: [
    {
      field: 'fullname',
      type: 'String',
      get: (customer) => {
        return customer.firstname + ' ' + customer.lastname;
      },
      search: function (query, search) {
        let split = search.split(' ');

        var searchCondition = {
          [Op.and]: [
            { firstname: { [Op.like]: `%${split[0]}%` } },
            { lastname: { [Op.like]: `%${split[1]}%` } },
          ],
        };

        query.where[Op.and][0][Op.or].push(searchCondition);

        return query;
      },
    },
  ],
});

For case insensitive search using PostgreSQL database use iLike operator. See Sequelize operators documentation.

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

collection('customers', {
  fields: [{
    field: 'fullname',
    type: 'String',
    get: (customer) => {
      return customer.firstname + ' ' + customer.lastname;
    },
    search(search) {
      let names = search.split(' ');
    ​
      return {
        firstname: names[0],
        lastname: names[1]
      };
    }
  }]
});

class Forest::Customer
  include ForestLiana::Collection
​
  collection :Customer
​
  search_fullname = lambda do |query, search|
    firstname, lastname = search.split
​
    # Injects your new filter into the WHERE clause.
    query.where_clause.send(:predicates)[0] << " OR (firstname = '#{firstname}' AND lastname = '#{lastname}')"
​
    query
  end
​
  field :fullname, type: 'String', set: set_fullname, search: search_fullname do
    "#{object.firstname} #{object.lastname}"
  end
end

Filtering

This feature is only available on agents version 6.7+ (version 6.2+ for Rails).

To perform a filter on a Smart Field, you need to write the filter query logic, which is specific to your use case. In the example hereunder, the fullname is filtered by checking conditions on the firstname and lastname depending on the filter operator selected.

SQL
Mongoose
Rails

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

const { Op } = models.Sequelize;

collection('customers', {
  fields: [
    {
      field: 'fullname',
      isFilterable: true,
      type: 'String',
      get: (customer) => {
        return customer.firstname + ' ' + customer.lastname;
      },
      filter({ condition, where }) {
        const firstWord = !!condition.value && condition.value.split(' ')[0];
        const secondWord = !!condition.value && condition.value.split(' ')[1];

        switch (condition.operator) {
          case 'equal':
            return {
              [Op.and]: [
                { firstname: firstWord },
                { lastname: secondWord || '' },
              ],
            };
          case 'ends_with':
            if (!secondWord) {
              return {
                lastName: { [Op.like]: `%${firstWord}` },
              };
            }
            return {
              [Op.and]: [
                { firstName: { [Op.like]: `%${firstWord}` } },
                { lastName: secondWord },
              ],
            };

          // ... And so on with the other operators not_equal, starts_with, etc.

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

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

collection('customer', {
  actions: [],
  fields: [
    {
      field: 'fullName',
      type: 'String',
      isFilterable: true,
      get: (customer) => {
        return customer.firstname + ' ' + customer.lastname;
      },
      filter({ condition, where }) {
        const firstWord = !!condition.value && condition.value.split(' ')[0];
        const secondWord = !!condition.value && condition.value.split(' ')[1];

        switch (condition.operator) {
          case 'equal':
            return {
              $and: [{ firstname: firstWord }, { lastname: secondWord || '' }],
            };
          case 'ends_with':
            if (!secondWord) {
              return {
                lastname: { $regex: `.*${firstWord}` },
              };
            }
            return {
              $and: [
                { firstname: { $regex: `.*${firstWord}` } },
                { lastname: secondWord },
              ],
            };

          // ... And so on with the other operators not_equal, starts_with, etc.

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

class Forest::Customer
  include ForestLiana::Collection

  collection :Customer

  filter_fullname = lambda do |condition, where|
    first_word = condition['value'] && condition['value'].split[0]
    second_word = condition['value'] && condition['value'].split[1]

    case condition['operator']
    when 'equal'
      "firstname = '#{first_word}' AND lastname = '#{second_word}'"
    when 'ends_with'
      if second_word.nil?
        "lastname LIKE '%#{first_word}'"
      else
        "firstname LIKE '%#{first_word}' AND lastname = '#{second_word}'"
      end
    # ... And so on with the other operators not_equal, starts_with, etc.
    end
  end

  field :fullname, type: 'String', is_read_only: false, is_required: true, is_filterable: true, filter: filter_fullname do
    "#{object.firstname} #{object.lastname}"
  end
end

Make sure you set the option isFilterable: true in the field definition of your code. Then, you will be able to toggle the “Filtering enabled” option in the browser, in your Fields Settings.

Sorting

Sorting on a Smart Field is not natively supported in Forest. However you can check out those guides:

Available Field Options

Here are the list of available options to customize your Smart Field:

Name	Type	Description
field	string	The name of your Smart Field.
type	string	Type of your field. Can be `Boolean`, `Date`, `Json`,`Dateonly`, `Enum`, `File`, `Number, ['String']` or `String` .
enums	array of strings	(optional) Required only for the `Enum` type. This is where you list all the possible values for your input field.
description	string	(optional) Add a description to your field.
reference	string	(optional) Configure the Smart Field as a Smart Relationship.
isReadOnly	boolean	(optional) If `true`, the Smart Field won’t be editable in the browser. Default is `true` if there’s no `set` option declared.
isRequired	boolean	(optional) If true, your Smart Field will be set as required in the browser. Default is false.

You can define a widget for a smart field from the settings of your collection.

Building Performant Smart Fields

To optimize your smart field performance, we recommend using a mechanism of batching and caching data requests. Implement them using the DataLoader which is a generic utility to be used as part of your application’s data fetching layer to provide a simplified and consistent API over various remote data sources.

Smart field declaration

SQL
Mongoose

const DataLoader = require('dataloader');

const authorLoader = new DataLoader(async (authorKeys) => {
  const authors = await users.findAll({
    where: { id: authorKeys },
  });

  const authorsById = new Map(authors.map((user) => [user.id, user]));

  return authorKeys.map((authorKey) => authorsById.get(authorKey));
});

collection('posts', {
  actions: [],
  fields: [
    {
      field: 'author_name',
      type: 'String',
      get: async (record) => {
        const author = await authorLoader.load(record.authorKey);

        return author.name;
      },
    },
  ],
  segments: [],
});

const { collection } = require('forest-express-mongoose');
const { Address } = require('../models');
const Dataloader = require('dataloader');

const addressLoader = new Dataloader((customerIds) => {
  const addresses = await models.addresses.find({
    customer_id: {
      $in: customerIds
    }
  });

  const addressesByCustomerId = new Map(addresses.map(
    address => [address.customer_id, address]
  ));

  return customerIds.map(customerId => addressesByCustomerId.get(customerId));
})

collection('customers', {
  fields: [{
    field: 'full_address',
    type: 'String',
    get: (customer) => {
      return addressLoader.load(customer.id)
        .then((address) => {
          return address.address_line_1 + '\n' +
            address.address_line_2 + '\n' +
            address.address_city + ' ' + address.country;
        });
    }
  }]
});

​What is a Smart Field?

​Creating a Smart Field

​Updating a Smart Field

​Searching, Sorting and Filtering on a Smart Field

​Filtering

​Sorting

​Available Field Options

​Building Performant Smart Fields

​Smart field declaration

​

What is a Smart Field?

Creating a Smart Field

Updating a Smart Field

Searching, Sorting and Filtering on a Smart Field

Filtering

Sorting

Available Field Options

Building Performant Smart Fields

Smart field declaration