Module: Compo::UrlReferenceable

Included in:
ArrayBranch, HashBranch, Leaf
Defined in:
lib/compo/url_referenceable.rb

Overview

Adds ID-based ‘URL’s to Compo classes

For the purposes of this module, a URL is a string of slash-delimited IDs representing the location of a Composite in the tree structure formed by its ancestors. Depending on the types of IDs used in the structure, the URLs may not actually be literal Uniform Resource Locators.

This module expects its includer to define #parent and #id. These are defined, for example, by the Compo::ParentTracker mixin.

Instance Method Summary collapse

Instance Method Details

#child_url(child_id) ⇒ String

Returns the URL of a child of this object, with the given ID

This defaults to joining the ID to this object’s URL with a slash.

Examples:

Gets the URL of the child of an object without a parent.

orphan.child_url(:id)
#=> '/id'

Gets the URL of the child of an object with a parent.

leaf.child_url(:id)
#=> 'grandparent_id/parent_id/id'

Parameters:

  • child_id (Object) —

    The ID of the child whose URL is sought.

Returns:

  • (String) —

    The URL of the child with the given ID.



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# File 'lib/compo/url_referenceable.rb', line 48

def child_url(child_id)
  [url, child_id].join('/')
end

#parent_url ⇒ String

Returns the URL of this object’s parent

Examples:

Gets the parent URL of an object with no parent.

orphan.parent_url
#=> nil

Gets the URL of an object with a parent.

leaf.parent_url
#=> 'grandparent_id/parent_id'

Returns:

  • (String) —

    The URL of this object’s parent, or nil if there is no parent.



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# File 'lib/compo/url_referenceable.rb', line 64

def parent_url
  parent.nil? ? nil : parent.url
end

#url ⇒ String

Returns the URL of this object

The #url of a Composite is defined inductively as ” for composites that have no parent, and the joining of the parent URL and the current ID otherwise.

The result of #url can be used to give a URL hierarchy to Composites.

Examples:

Gets the URL of an object with no parent.

orphan.url
#=> ''

Gets the URL of an object with a parent.

leaf.url
#=> 'grandparent_id/parent_id/id'

Returns:

  • (String) —

    The URL of this object.



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# File 'lib/compo/url_referenceable.rb', line 29

def url
  parent.child_url(id)
end