Class: GraphQL::Query::Variables

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/graphql/query/variables.rb

Overview

Read-only access to query variables, applying default values if needed.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ctx, ast_variables, provided_variables) ⇒ Variables

Returns a new instance of Variables.



13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
# File 'lib/graphql/query/variables.rb', line 13

def initialize(ctx, ast_variables, provided_variables)
  schema = ctx.schema
  @context = ctx

  @provided_variables = GraphQL::Argument.deep_stringify(provided_variables)
  @errors = []
  @storage = ast_variables.each_with_object({}) do |ast_variable, memo|
    # Find the right value for this variable:
    # - First, use the value provided at runtime
    # - Then, fall back to the default value from the query string
    # If it's still nil, raise an error if it's required.
    variable_type = schema.type_from_ast(ast_variable.type)
    if variable_type.nil?
      # Pass -- it will get handled by a validator
    else
      variable_name = ast_variable.name
      default_value = ast_variable.default_value
      provided_value = @provided_variables[variable_name]
      value_was_provided =  @provided_variables.key?(variable_name)

      begin
        validation_result = variable_type.validate_input(provided_value, ctx)
      rescue GraphQL::CoercionError => ex
        validation_result = GraphQL::Query::InputValidationResult.new
        validation_result.add_problem(ex.message)
      end

      if !validation_result.valid?
        # This finds variables that were required but not provided
        @errors << GraphQL::Query::VariableValidationError.new(ast_variable, variable_type, provided_value, validation_result)
      elsif value_was_provided
        # Add the variable if a value was provided
        memo[variable_name] = variable_type.coerce_input(provided_value, ctx)
      elsif default_value != nil
        # Add the variable if it wasn't provided but it has a default value (including `null`)
        memo[variable_name] = GraphQL::Query::LiteralInput.coerce(variable_type, default_value, self)
      end
    end
  end
end

Instance Attribute Details

#contextObject (readonly)

Returns the value of attribute context.



11
12
13
# File 'lib/graphql/query/variables.rb', line 11

def context
  @context
end

#errorsArray<GraphQL::Query::VariableValidationError> (readonly)

Returns Any errors encountered when parsing the provided variables and literal values.

Returns:



9
10
11
# File 'lib/graphql/query/variables.rb', line 9

def errors
  @errors
end