NAME
GraphQL::Type::Library - GraphQL type library
SYNOPSIS
use GraphQL::Type::Library -all;
has name => (is => 'ro', isa => StrNameValid, required => 1);DESCRIPTION
Provides Type::Tiny types.
TYPES
StrNameValid
If called with a string that is not a valid GraphQL name, will throw an exception. Suitable for passing to an isa constraint in Moo.
ValuesMatchTypes
Subtype of "HashRef" in Types::Standard, whose values are hash-refs. Takes two parameters:
- value keyname
-
Optional within the second-level hashes.
- type keyname
-
Values will be a GraphQL::Type. Mandatory within the second-level hashes.
In the second-level hashes, the values (if given) must pass the GraphQL type constraint.
FieldMapInput
Hash-ref mapping field names to a hash-ref description. Description keys, all optional except type:
- type
-
GraphQL input type for the field.
- default_value
-
Default value for this argument if none supplied. Must be same type as the
type(implemented with type "ValuesMatchTypes". NB this is a Perl value, not a JSON/GraphQL value. - description
-
Description.
FieldMapOutput
Hash-ref mapping field names to a hash-ref description. Description keys, all optional except type:
type
GraphQL output type for the field.
args
subscribe
Code-ref to return a subscription to the field from a given source-object. See "subscribe" in GraphQL::Subscription.
deprecation_reason
Reason if deprecated. If given, also sets a boolean key of is_deprecated to true.
description
Description.
resolve
Code-ref to return a given property from a given source-object. A key concept is to remember that the "object" on which these fields exist, were themselves returned by other fields.
There are no restrictions on what you can return, so long as it is a scalar, and if your return type is a list, that scalar is an array-ref.
Emphasis has been put on there being Perl values here. Conversion between Perl and GraphQL values is taken care of by scalar types, and it is only scalar information that will be returned to the client, albeit in the shape dictated by the object types.
An example function that takes a name and GraphQL type, and returns a field definition, with a resolver that calls read-only Moo accessors, suitable for placing (several of) inside the hash-ref defining a type's fields:
sub _make_moo_field {
my ($field_name, $type) = @_;
($field_name => { resolve => sub {
my ($root_value, $args, $context, $info) = @_;
my @passon = %$args ? ($args) : ();
return undef unless $root_value->can($field_name);
$root_value->$field_name(@passon);
}, type => $type });
}
# ...
fields => {
_make_moo_field(name => $String),
_make_moo_field(description => $String),
},
# ...The code-ref will be called with these parameters:
$source
The Perl entity (possibly a blessed object) returned by the resolver that conjured up this GraphQL object.
$args
Hash-ref of the arguments passed to the field. The values will be Perl values.
$context
The "context" value supplied to the call to "execute" in GraphQL::Execution. Can be used for authenticated user information, or a per-request cache.
$info
A hash-ref describing this node of the request; see "info hash" below.
info hash
field_name
The real name of this field.
field_nodes
The array of Abstract Syntax Tree (AST) nodes that refer to this field in this "selection set" (set of fields) on this object. There may be more than one such set for a given field, if it is requested more than once with a given name (not with an alias) - the results will be combined into one reply.
return_type
The return type.
parent_type
The type of which this field is part.
path
The hierarchy of fields from the query root to this field-resolution.
schema
GraphQL::Schema object.
fragments
Any fragments applying to this request.
root_value
The "root value" given to execute.
operation
A hash-ref describing the operation (query, etc) being executed.
variable_values
the operation's arguments, filled out with the variables hash supplied to the request.
promise_code
A hash-ref. The relevant value supplied to the execute function.
Int32Signed
32-bit signed integer.
ArrayRefNonEmpty
Like "ArrayRef" in Types::Standard but requires at least one entry.
UniqueByProperty
An ArrayRef, its members' property (the one in the parameter) can occur only once.
use Moo;
use GraphQL::Type::Library -all;
has types => (
is => 'ro',
isa => UniqueByProperty['name'] & ArrayRef[InstanceOf['GraphQL::Type::Object']],
required => 1,
);ExpectObject
A Maybe[HashRef] that produces a GraphQL-like message if it fails, saying "found not an object".
DocumentLocation
Hash-ref that has keys line and column which are Int.
JSONable
A value that will be JSON-able.
ErrorResult
Hash-ref that has keys message, location, path, extensions.
ExecutionResult
Hash-ref that has keys data and/or errors.
The errors, if present, will be an array-ref of ErrorResult.
The data if present will be the return data, being a hash-ref whose values are either further hashes, array-refs, or scalars. It will be JSON-able.
ExecutionPartialResult
Hash-ref that has keys data and/or errors. Like "ExecutionResult" above, but the errors, if present, will be an array-ref of GraphQL::Error objects.
Promise
An object that has then, resolve, reject methods.
PromiseCode
A hash-ref with three keys: resolve, all, reject. The values are all code-refs that take one value (for all, an array-ref), and create the given kind of Promise.
Must also have a new key for use with GraphQL::Subscription, with code returning a promise that can then have resolve or reject called on it.
AsyncIterator
An instance of GraphQL::AsyncIterator.
AUTHOR
Ed J, <etj at cpan.org>