Module: GlobalID::Locator

Defined in:
lib/global_id/locator.rb

Defined Under Namespace

Classes: BaseLocator, BlockLocator, UnscopedLocator

Class Method Summary collapse

Class Method Details

.locate(gid, options = {}) ⇒ Object

Takes either a GlobalID or a string that can be turned into a GlobalID

Options:

  • :only - A class, module or Array of classes and/or modules that are allowed to be located. Passing one or more classes limits instances of returned classes to those classes or their subclasses. Passing one or more modules in limits instances of returned classes to those including that module. If no classes or modules match, nil is returned.


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# File 'lib/global_id/locator.rb', line 15

def locate(gid, options = {})
  if gid = GlobalID.parse(gid)
    locator_for(gid).locate gid if find_allowed?(gid.model_class, options[:only])
  end
end

.locate_many(gids, options = {}) ⇒ Object

Takes an array of GlobalIDs or strings that can be turned into a GlobalIDs. All GlobalIDs must belong to the same app, as they will be located using the same locator using its locate_many method.

By default the GlobalIDs will be located using Model.find(array_of_ids), so the models must respond to that finder signature.

This approach will efficiently call only one #find (or #where(id: id), when using ignore_missing) per model class, but still interpolate the results to match the order in which the gids were passed.

Options:

  • :only - A class, module or Array of classes and/or modules that are allowed to be located. Passing one or more classes limits instances of returned classes to those classes or their subclasses. Passing one or more modules in limits instances of returned classes to those including that module. If no classes or modules match, nil is returned.

  • :ignore_missing - By default, locate_many will call #find on the model to locate the ids extracted from the GIDs. In Active Record (and other data stores following the same pattern), #find will raise an exception if a named ID can't be found. When you set this option to true, we will use #where(id: ids) instead, which does not raise on missing records.


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# File 'lib/global_id/locator.rb', line 41

def locate_many(gids, options = {})
  if (allowed_gids = parse_allowed(gids, options[:only])).any?
    locator = locator_for(allowed_gids.first)
    locator.locate_many(allowed_gids, options)
  else
    []
  end
end

.locate_many_signed(sgids, options = {}) ⇒ Object

Takes an array of SignedGlobalIDs or strings that can be turned into a SignedGlobalIDs. The SignedGlobalIDs are located using Model.find(array_of_ids), so the models must respond to that finder signature.

This approach will efficiently call only one #find per model class, but still interpolate the results to match the order in which the gids were passed.

Options:

  • :only - A class, module or Array of classes and/or modules that are allowed to be located. Passing one or more classes limits instances of returned classes to those classes or their subclasses. Passing one or more modules in limits instances of returned classes to those including that module. If no classes or modules match, nil is returned.


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# File 'lib/global_id/locator.rb', line 75

def locate_many_signed(sgids, options = {})
  locate_many sgids.collect { |sgid| SignedGlobalID.parse(sgid, options.slice(:for)) }.compact, options
end

.locate_signed(sgid, options = {}) ⇒ Object

Takes either a SignedGlobalID or a string that can be turned into a SignedGlobalID

Options:

  • :only - A class, module or Array of classes and/or modules that are allowed to be located. Passing one or more classes limits instances of returned classes to those classes or their subclasses. Passing one or more modules in limits instances of returned classes to those including that module. If no classes or modules match, nil is returned.


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# File 'lib/global_id/locator.rb', line 58

def locate_signed(sgid, options = {})
  SignedGlobalID.find sgid, options
end

.use(app, locator = nil, &locator_block) ⇒ Object

Tie a locator to an app. Useful when different apps collaborate and reference each others' Global IDs.

The locator can be either a block or a class.

Using a block:

GlobalID::Locator.use :foo do |gid|
  FooRemote.const_get(gid.model_name).find(gid.model_id)
end

Using a class:

GlobalID::Locator.use :bar, BarLocator.new

class BarLocator
  def locate(gid)
    @search_client.search name: gid.model_name, id: gid.model_id
  end
end

Raises:

  • (ArgumentError)

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# File 'lib/global_id/locator.rb', line 99

def use(app, locator = nil, &locator_block)
  raise ArgumentError, 'No locator provided. Pass a block or an object that responds to #locate.' unless locator || block_given?

  URI::GID.validate_app(app)

  @locators[normalize_app(app)] = locator || BlockLocator.new(locator_block)
end