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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).

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Creating a Smart Field

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

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Updating a Smart Field

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.

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

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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. 
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.

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Sorting

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

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Available Field Options

Here are the list of available options to customize your Smart Field:
NameTypeDescription
fieldstringThe name of your Smart Field.
typestringType of your field. Can be Boolean, Date, Json,Dateonly, Enum, File, Number, ['String'] or String .
enumsarray of strings(optional) Required only for the Enum type. This is where you list all the possible values for your input field.
descriptionstring(optional) Add a description to your field.
referencestring(optional) Configure the Smart Field as a Smart Relationship.
isReadOnlyboolean(optional) If true, the Smart Field won’t be editable in the browser. Default is true if there’s no set option declared.
isRequiredboolean(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.

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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.

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Smart field declaration

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