class Aws::Record::ItemCollection
Public Class Methods
# File lib/aws-record/record/item_collection.rb, line 19 def initialize(search_method, search_params, model, client) @search_method = search_method @search_params = search_params @model_filter = @search_params.delete(:model_filter) @model = model @client = client end
Public Instance Methods
Provides an enumeration of the results of a query or scan operation on your table, automatically converted into item classes.
WARNING: This will enumerate over your entire partition in the case of query, and over your entire table in the case of scan, save for key and filter expressions used. This means that enumerable operations that iterate over the full result set could make many network calls, or use a lot of memory to build response objects. Use with caution.
@return [Enumerable<Aws::Record>] an enumeration over the results of
your query or scan request. These results are automatically converted into items on your behalf.
# File lib/aws-record/record/item_collection.rb, line 39 def each(&block) return enum_for(:each) unless block_given? items.each_page do |page| @last_evaluated_key = page.last_evaluated_key items_array = _build_items_from_response(page.items, @model) items_array.each do |item| yield item end end end
Checks if the query/scan result is completely blank.
WARNING: This can and will query your entire partition, or scan your entire table, if no results are found. Especially if your table is large, use this with extreme caution.
@return [Boolean] true if the query/scan result is empty, false
otherwise.
# File lib/aws-record/record/item_collection.rb, line 84 def empty? items.each_page do |page| return false if !page.items.empty? end true end
Provides the pagination key most recently used by the underlying client. This can be useful in the case where you're exposing pagination to an outside caller, and want to be able to “resume” your scan in a new call without starting over.
@return [Hash] a hash representing an attribute key/value pair, suitable
for use as the +exclusive_start_key+ in another query or scan operation. If there are no more pages in the result, will be nil.
# File lib/aws-record/record/item_collection.rb, line 72 def last_evaluated_key @last_evaluated_key end
Provides the first “page” of responses from your query operation. This will only make a single client call, and will provide the items, if any exist, from that response. It will not attempt to follow up on pagination tokens, so this is not guaranteed to include all items that match your search.
@return [Array<Aws::Record>] an array of the record items found in the
first page of reponses from the query or scan call.
# File lib/aws-record/record/item_collection.rb, line 58 def page search_response = items @last_evaluated_key = search_response.last_evaluated_key _build_items_from_response(search_response.items, @model) end
Private Instance Methods
# File lib/aws-record/record/item_collection.rb, line 92 def _build_items_from_response(items, model) ret = [] items.each do |item| model_class = @model_filter ? @model_filter.call(item) : model next unless model_class record = model_class.new data = record.instance_variable_get("@data") model_class.attributes.attributes.each do |name, attr| data.set_attribute(name, attr.extract(item)) end data.clean! data.new_record = false ret << record end ret end
# File lib/aws-record/record/item_collection.rb, line 109 def items @_items ||= @client.send(@search_method, @search_params) end