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(schema, warden, ast_variables, provided_variables) ⇒ Variables

Returns a new instance of Variables.



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

def initialize(schema, warden, ast_variables, provided_variables)
  @schema = schema
  @warden = warden
  @provided_variables = 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)
    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)

    validation_result = variable_type.validate_input(provided_value, @warden)
    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)
    elsif default_value
      # 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, {})
    end
  end
end

Instance Attribute Details

#errors ⇒ Array<GraphQL::Query::VariableValidationError> (readonly)

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

Returns:



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

def errors
  @errors
end