Class: GraphQL::Query::Variables

Inherits:
Object
  • Object
show all
Extended by:
Delegate
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

Methods included from Delegate

def_delegators

Constructor Details

#initialize(ctx, ast_variables, provided_variables) ⇒ Variables

Returns a new instance of Variables.


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

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

      validation_result = variable_type.validate_input(provided_value, ctx)
      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        # 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


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# 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:


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

def errors
  @errors
end