Class: OccamsRecord::EagerLoaders::AdHocBase

Inherits:
Object
  • Object
show all
Includes:
Builder
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 collapse

Instance Method Summary collapse

Methods included from Builder

#eager_load, #eager_load_many, #eager_load_one, #nest

Constructor Details

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

Initialize a new add hoc association.

Parameters:

  • name (Symbol) —

    name of attribute to load records into

  • mapping (Hash) —

    a Hash with the key being the parent id and the value being fkey in the child

  • 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)

  • parent (OccamsRecord::EagerLoaders::Tracer) (defaults to: nil) —

    the eager loader this one is nested under (if any)

Yields:

  • eager load associations nested under this one



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# File 'lib/occams-record/eager_loaders/ad_hoc_base.rb', line 32

def initialize(name, mapping, sql, binds: {}, model: nil, use: nil, parent: nil, &builder)
  @name, @mapping = name.to_s, mapping
  @sql, @binds, @use, @model = sql, binds, use, model
  @tracer = Tracer.new(name, parent)
  @eager_loaders = EagerLoaders::Context.new(@model, tracer: @tracer)
  if builder
    if builder.arity > 0
      builder.call(self)
    else
      instance_exec(&builder)
    end
  end
end

Instance Attribute Details

#eager_loaders ⇒ OccamsRecord::EagerLoaders::Context (readonly)

Returns:



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# File 'lib/occams-record/eager_loaders/ad_hoc_base.rb', line 18

def eager_loaders
  @eager_loaders
end

#name ⇒ String (readonly)

Returns association name.

Returns:

  • (String) —

    association name



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# File 'lib/occams-record/eager_loaders/ad_hoc_base.rb', line 12

def name
  @name
end

#tracer ⇒ OccamsRecord::EagerLoaders::Tracer | nil (readonly)

Returns a reference to this eager loader and its parent (if any).

Returns:



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# File 'lib/occams-record/eager_loaders/ad_hoc_base.rb', line 15

def tracer
  @tracer
end

Instance Method Details

#run(rows, query_logger: nil, measurements: 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) 


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# File 'lib/occams-record/eager_loaders/ad_hoc_base.rb', line 52

def run(rows, query_logger: nil, measurements: nil)
  fkey_binds = calc_fkey_binds rows
  assoc =
    if fkey_binds.all? { |_, vals| vals.any? }
      binds = @binds.merge(fkey_binds)
      RawQuery.new(@sql, binds, use: @use, eager_loaders: @eager_loaders, query_logger: query_logger, measurements: measurements).run
    else
      []
    end
  merge! assoc, rows
  nil
end