Class: OccamsRecord::EagerLoaders::AdHocBase

Inherits:

Object

• Object
• OccamsRecord::EagerLoaders::AdHocBase

Defined in:

lib/occams-record/eager_loaders/ad_hoc_base.rb

Overview

Base class for eager loading ad hoc associations.

Direct Known Subclasses

AdHocMany, AdHocOne

Instance Attribute Summary

• #name ⇒ String readonly

  Association name.

Instance Method Summary

• #initialize(name, mapping, sql, binds: {}, model: nil, use: nil) { ... } ⇒ AdHocBase constructor

  Initialize a new add hoc association.

• #run(rows, query_logger: nil) ⇒ Object

  Run the query and merge the results into the given rows.

Constructor Details

#initialize(name, mapping, sql, binds: {}, model: nil, use: nil) { ... } ⇒ AdHocBase

Initialize a new add hoc association.

Parameters:

• name (Symbol) —

  name of attribute to load records into

• mapping (Hash) —

  a one element Hash with the key being the local/child id and the value being the foreign/parent id

• sql (String) —

  the SQL to query the associated records. Include a bind params called ‘%ids’ for the foreign/parent ids.

• binds (Hash) (defaults to: {}) —

  any additional binds for your query.

• model (ActiveRecord::Base) (defaults to: nil) —

  optional - ActiveRecord model that represents what you’re loading. required when using Sqlite.

• use (Array<Module>) (defaults to: nil) —

  optional - Ruby modules to include in the result objects (single or array)

Yields:

• eager load associations nested under this one

Raises:

• (ArgumentError)

# File 'lib/occams-record/eager_loaders/ad_hoc_base.rb', line 21

def initialize(name, mapping, sql, binds: {}, model: nil, use: nil, &eval_block)
  @name = name.to_s
  @sql, @binds, @use, @model, @eval_block = sql, binds, use, model, eval_block
  raise ArgumentError, "Add-hoc eager loading mapping must contain exactly one key-value pair" unless mapping.size == 1
  @local_key = mapping.keys.first
  @foreign_key = mapping.fetch(@local_key)
end

Instance Attribute Details

#name ⇒ String (readonly)

Returns association name.

Returns:

• (String) —

  association name

# File 'lib/occams-record/eager_loaders/ad_hoc_base.rb', line 8

def name
  @name
end

Instance Method Details

#run(rows, query_logger: nil) ⇒ Object

Run the query and merge the results into the given rows.

Parameters:

• rows (Array<OccamsRecord::Results::Row>) —

  Array of rows used to calculate the query.

• query_logger (Array<String>) (defaults to: nil)

# File 'lib/occams-record/eager_loaders/ad_hoc_base.rb', line 35

def run(rows, query_logger: nil)
  calc_ids(rows) { |ids|
    binds = @binds.merge({:ids => ids})
    assoc_rows = RawQuery.new(@sql, binds, use: @use, query_logger: query_logger, &@eval_block).model(@model).run
    merge! assoc_rows, rows
  }
end