Class: CoreLibrary::LinkPagination

Inherits:
PaginationStrategy show all
Defined in:
lib/apimatic-core/pagination/strategies/link_pagination.rb

Overview

Implements a pagination strategy that extracts the next page link from API responses using a JSON pointer.

This class updates the request builder with query parameters from the next page link and applies a metadata wrapper to the paged response.

Instance Attribute Summary

Attributes inherited from PaginationStrategy

#metadata_wrapper

Instance Method Summary collapse

Constructor Details

#initialize(next_link_pointer, metadata_wrapper) ⇒ LinkPagination

Initializes a LinkPagination instance with the given next link pointer and metadata wrapper.

Parameters:

  • next_link_pointer (String) —

    JSON pointer to extract the next page link from the API response.

  • metadata_wrapper (Proc) —

    A callable to wrap the paged response metadata.

Raises:

  • (ArgumentError) —

    If next_link_pointer is nil.



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# File 'lib/apimatic-core/pagination/strategies/link_pagination.rb', line 12

def initialize(next_link_pointer, metadata_wrapper)
  super(metadata_wrapper)

  raise ArgumentError, 'Next link pointer for cursor based pagination cannot be nil' if next_link_pointer.nil?

  @next_link_pointer = next_link_pointer
  @next_link = nil
end

Instance Method Details

#applicable?(response) ⇒ Boolean

Determines whether the link pagination strategy is applicable based on the given HTTP response.

Parameters:

  • response (HttpResponse, nil) —

    The response from the previous API call.

Returns:

  • (Boolean) —

    true if this strategy is applicable based on the response; false otherwise.



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# File 'lib/apimatic-core/pagination/strategies/link_pagination.rb', line 26

def applicable?(response)
  return true if response.nil?

  @next_link = response.get_value_by_json_pointer(@next_link_pointer)

  !@next_link.nil?
end

#apply(paginated_data) ⇒ Object?

Updates the request builder with query parameters from the next page link extracted from the last API response.

Parameters:

  • paginated_data (Object) —

    An object containing the last API response and the current request builder.

Returns:

  • (Object, nil) —

    A new request builder with updated query parameters, or nil if no next link is found.



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# File 'lib/apimatic-core/pagination/strategies/link_pagination.rb', line 38

def apply(paginated_data)
  last_response = paginated_data.last_response
  request_builder = paginated_data.request_builder

  # If there is no response yet, this is the first page
  if last_response.nil?
    @next_link = nil
    return request_builder
  end

  @next_link = last_response.get_value_by_json_pointer(@next_link_pointer)

  return nil if @next_link.nil?

  query_params = ApiHelper.get_query_parameters(@next_link)
  updated_query_params = DeepCloneUtils.deep_copy(request_builder.query_params)
  updated_query_params.merge!(query_params)

  request_builder.clone_with(query_params: updated_query_params)
end

#apply_metadata_wrapper(paged_response) ⇒ Object

Applies the metadata wrapper to the paged response, including the next page link.

Parameters:

  • paged_response (Object) —

    The API response object for the current page.

Returns:

  • (Object) —

    The result of the metadata wrapper, typically containing the response and next link.



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# File 'lib/apimatic-core/pagination/strategies/link_pagination.rb', line 63

def apply_metadata_wrapper(paged_response)
  @metadata_wrapper.call(paged_response, @next_link)
end