Class: Candid::Internal::CursorPageIterator

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/candid/internal/iterators/cursor_page_iterator.rb

Instance Method Summary collapse

Constructor Details

#initialize(initial_cursor:, cursor_field:, &block) ⇒ Candid::Internal::CursorPageIterator

Instantiates a CursorPageIterator, an Enumerable class which wraps calls to a cursor-based paginated API and yields pages of items.

Parameters:

  • initial_cursor (String) —

    The initial cursor to use when iterating, if any.

  • cursor_field (Symbol) —

    The name of the field in API responses to extract the next cursor from.

  • block (Proc) —

    A block which is responsible for receiving a cursor to use and returning the given page from the API.



14
15
16
17
18
19
 
# File 'lib/candid/internal/iterators/cursor_page_iterator.rb', line 14

def initialize(initial_cursor:, cursor_field:, &block)
  @need_initial_load = initial_cursor.nil?
  @cursor = initial_cursor
  @cursor_field = cursor_field
  @get_next_page = block
end

Instance Method Details

#each(&block) ⇒ NilClass

Iterates over each page returned by the API.

Parameters:

  • block (Proc) —

    The block which each retrieved page is yielded to.

Returns:

  • (NilClass) 


25
26
27
28
29
 
# File 'lib/candid/internal/iterators/cursor_page_iterator.rb', line 25

def each(&block)
  while (page = get_next)
    block.call(page)
  end
end

#get_next ⇒ Boolean

Retrieves the next page from the API.

Returns:

  • (Boolean) 


41
42
43
44
45
46
47
48
 
# File 'lib/candid/internal/iterators/cursor_page_iterator.rb', line 41

def get_next
  return if !@need_initial_load && @cursor.nil?

  @need_initial_load = false
  next_page = @get_next_page.call(@cursor)
  @cursor = next_page.send(@cursor_field)
  next_page
end

#has_next? ⇒ Boolean

Whether another page will be available from the API.

Returns:

  • (Boolean) 


34
35
36
 
# File 'lib/candid/internal/iterators/cursor_page_iterator.rb', line 34

def has_next?
  @need_initial_load || !@cursor.nil?
end