Class: GraphQL::Stitching::Executor::BoundarySource

Inherits:
Dataloader::Source
  • Object
show all
Defined in:
lib/graphql/stitching/executor.rb

Instance Method Summary collapse

Constructor Details

#initialize(executor, location) ⇒ BoundarySource

Returns a new instance of BoundarySource.



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# File 'lib/graphql/stitching/executor.rb', line 53

def initialize(executor, location)
  @executor = executor
  @location = location
end

Instance Method Details

#build_document(origin_sets_by_operation, operation_name = nil) ⇒ Object

Builds batched boundary queries “query MyOperation_2_3($var:VarType) {

_0_result: list(keys:["a","b","c"]) { boundarySelections... }
_1_0_result: item(key:"x") { boundarySelections... }
_1_1_result: item(key:"y") { boundarySelections... }
_1_2_result: item(key:"z") { boundarySelections... }

}“



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# File 'lib/graphql/stitching/executor.rb', line 96

def build_document(origin_sets_by_operation, operation_name = nil)
  variable_defs = {}
  query_fields = origin_sets_by_operation.map.with_index do |(op, origin_set), batch_index|
    variable_defs.merge!(op["variables"])
    boundary = op["boundary"]
    key_selection = "_STITCH_#{boundary["selection"]}"

    if boundary["list"]
      input = JSON.generate(origin_set.map { _1[key_selection] })
      "_#{batch_index}_result: #{boundary["field"]}(#{boundary["arg"]}:#{input}) #{op["selections"]}"
    else
      origin_set.map.with_index do |origin_obj, index|
        input = JSON.generate(origin_obj[key_selection])
        "_#{batch_index}_#{index}_result: #{boundary["field"]}(#{boundary["arg"]}:#{input}) #{op["selections"]}"
      end
    end
  end

  doc = String.new
  doc << "query" # << boundary fulfillment always uses query

  if operation_name
    doc << " " << operation_name
    origin_sets_by_operation.each_key do |op|
      doc << "_" << op["key"].to_s
    end
  end

  if variable_defs.any?
    variable_str = variable_defs.map { |k, v| "$#{k}:#{v}" }.join(",")
    doc << "(" << variable_str << ")"
  end

  doc << "{ " << query_fields.join(" ") << " }"

  return doc, variable_defs.keys
end

#extract_errors!(origin_sets_by_operation, errors) ⇒ Object

spec.graphql.org/June2018/#sec-Errors



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# File 'lib/graphql/stitching/executor.rb', line 153

def extract_errors!(origin_sets_by_operation, errors)
  ops = origin_sets_by_operation.keys
  origin_sets = origin_sets_by_operation.values
  pathed_errors_by_op_index_and_object_id = {}

  errors_result = errors.each_with_object([]) do |err, memo|
    err.delete("locations")
    path = err["path"]

    if path && path.length > 0
      result_alias = /^_(\d+)(?:_(\d+))?_result$/.match(path.first.to_s)

      if result_alias
        path = err["path"] = path[1..-1]

        origin_obj = if result_alias[2]
          origin_sets.dig(result_alias[1].to_i, result_alias[2].to_i)
        elsif path[0].is_a?(Integer) || /\d+/.match?(path[0].to_s)
          origin_sets.dig(result_alias[1].to_i, path.shift.to_i)
        end

        if origin_obj
          by_op_index = pathed_errors_by_op_index_and_object_id[result_alias[1].to_i] ||= {}
          by_object_id = by_op_index[origin_obj.object_id] ||= []
          by_object_id << err
          next
        end
      end
    end

    memo << err
  end

  if pathed_errors_by_op_index_and_object_id.any?
    pathed_errors_by_op_index_and_object_id.each do |op_index, pathed_errors_by_object_id|
      repath_errors!(pathed_errors_by_object_id, ops.dig(op_index, "insertion_path"))
      errors_result.concat(pathed_errors_by_object_id.values)
    end
  end
  errors_result.flatten!
end

#fetch(ops) ⇒ Object 



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# File 'lib/graphql/stitching/executor.rb', line 58

def fetch(ops)
  origin_sets_by_operation = ops.each_with_object({}) do |op, memo|
    origin_set = op["insertion_path"].reduce([@executor.data]) do |set, path_segment|
      mapped = set.flat_map { |obj| obj && obj[path_segment] }
      mapped.compact!
      mapped
    end

    if op["type_condition"]
      # operations planned around unused fragment conditions should not trigger requests
      origin_set.select! { _1["_STITCH_typename"] == op["type_condition"] }
    end

    memo[op] = origin_set if origin_set.any?
  end

  if origin_sets_by_operation.any?
    query_document, variable_names = build_document(origin_sets_by_operation, @executor.request.operation_name)
    variables = @executor.request.variables.slice(*variable_names)
    raw_result = @executor.supergraph.execute_at_location(@location, query_document, variables, @executor.request.context)
    @executor.query_count += 1

    merge_results!(origin_sets_by_operation, raw_result.dig("data"))

    errors = raw_result.dig("errors")
    @executor.errors.concat(extract_errors!(origin_sets_by_operation, errors)) if errors&.any?
  end

  ops.map { origin_sets_by_operation[_1] ? _1["key"] : nil }
end

#merge_results!(origin_sets_by_operation, raw_result) ⇒ Object 



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# File 'lib/graphql/stitching/executor.rb', line 134

def merge_results!(origin_sets_by_operation, raw_result)
  return unless raw_result

  origin_sets_by_operation.each_with_index do |(op, origin_set), batch_index|
    results = if op.dig("boundary", "list")
      raw_result["_#{batch_index}_result"]
    else
      origin_set.map.with_index { |_, index| raw_result["_#{batch_index}_#{index}_result"] }
    end

    next unless results&.any?

    origin_set.each_with_index do |origin_obj, index|
      origin_obj.merge!(results[index]) if results[index]
    end
  end
end