Class: HalClient::Collection

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/hal_client/collection.rb

Overview

Enumerable for items in a paged collection of HAL representations that are encoded using the IANA standard ‘item`, `next` and `prev` link rels.

This will fetch subsequent pages on iteration

Instance Method Summary collapse

Constructor Details

#initialize(first_page) ⇒ Collection

Initializes a collection starting at ‘first_page`.

first_page - The HalClient::Representation of the first page of

the collection to be iterated over.

Raises HalClient::NotACollectionError if ‘first_page` is not a

page of a collection.

Raises ArgumentError if ‘first_page` is some page other than

the first of the collection.



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# File 'lib/hal_client/collection.rb', line 22

def initialize(first_page)
  (fail NotACollectionError) unless first_page.has_related? "item"
  (fail ArgumentError, "Not the first page of the collection") if first_page.has_related? "prev"

  @first_page = first_page
end

Instance Method Details

#count(&blk) ⇒ Object

Returns the number of items in the collection if it is fast to calculate.

Raises NotImplementedError if any of the pages of the collection

have not already been cached.



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# File 'lib/hal_client/collection.rb', line 34

def count(&blk)
  (fail NotImplementedError, "Cowardly refusing to make an arbitrary number of HTTP requests") unless all_pages_cached?

  total = 0
  each_page do |p|
    total += p.related("item").count
  end

  total
end

#each(&blk) ⇒ Object

Iterates over the members of the collection fetching the next page as necessary.

Yields the next item of the iteration.



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# File 'lib/hal_client/collection.rb', line 49

def each(&blk)
  each_page do |a_page|
    a_page.related("item").each(&blk)
  end
end