AshBackpex.LoadSelectResolver (Ash Backpex v0.3.3)

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Resolves which Ash loads and selects are needed for a given set of Backpex fields.

This module analyzes the fields configured in an AshBackpex LiveResource and determines which ones are:

  • Attributes - Added to the select list
  • Relationships, Calculations, or Aggregates - Added to the load list

The adapter passes the select list to Ash.Query.ensure_selected/2, so it adds to the attributes Ash selects by default rather than replacing them. Records in the admin then carry the same attributes as records read anywhere else, which the changesets built by can?/3 and by updates rely on.

How It Works

The resolver examines each field name against the Ash resource schema:

  1. If the field is an attribute → add to select
  2. If the field is a relationship, calculation, or aggregate → add to load
  3. If the field doesn't exist on the resource → raise an error

Usage

This module is called internally by AshBackpex.Adapter to build queries. You typically don't need to use it directly, but it can be useful for debugging or custom adapter implementations:

fields = [
  title: %{module: Backpex.Fields.Text},
  author: %{module: Backpex.Fields.BelongsTo},
  word_count: %{module: Backpex.Fields.Number}
]

{loads, selects} = AshBackpex.LoadSelectResolver.resolve(MyApp.Blog.Post, fields)
# loads => [:author, :word_count]
# selects => [:title]

Summary

Types

field_list()
load()
select()

Functions

resolve(resource, fields)

Resolves field configurations into Ash loads and selects.

Types

field_list()

@type field_list() :: keyword()

load()

@type load() :: atom()

select()

@type select() :: atom()

Functions

resolve(resource, fields)

@spec resolve(Ash.Resource.t(), field_list()) :: {[load()], [select()]}

Resolves field configurations into Ash loads and selects.

Given an Ash resource module and a keyword list of Backpex field configurations, returns a tuple of {loads, selects} where:

  • loads - List of relationships, calculations, and aggregates to load
  • selects - List of attributes to select

Parameters

  • resource - An Ash.Resource module
  • fields - Keyword list of field configurations (field name → config map)

Returns

A tuple {loads, selects} where both are lists of atoms.

Raises

Raises an error if a field name doesn't correspond to any attribute, relationship, calculation, or aggregate on the resource.

Examples

iex> fields = [title: %{}, author: %{}, word_count: %{}]
iex> AshBackpex.LoadSelectResolver.resolve(MyApp.Post, fields)
{[:author, :word_count], [:title]}