graphql-php/type-system/index.html

424 lines
11 KiB
HTML
Executable File

<!DOCTYPE html>
<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Introduction - graphql-php</title>
<link rel="shortcut icon" href="../img/favicon.ico">
<link href='https://fonts.googleapis.com/css?family=Lato:400,700|Roboto+Slab:400,700|Inconsolata:400,700' rel='stylesheet' type='text/css'>
<link rel="stylesheet" href="../css/theme.css" type="text/css" />
<link rel="stylesheet" href="../css/theme_extra.css" type="text/css" />
<link rel="stylesheet" href="../css/highlight.css">
<script>
// Current page data
var mkdocs_page_name = "Introduction";
var mkdocs_page_input_path = "type-system\index.md";
var mkdocs_page_url = "/type-system/";
</script>
<script src="../js/jquery-2.1.1.min.js"></script>
<script src="../js/modernizr-2.8.3.min.js"></script>
<script type="text/javascript" src="../js/highlight.pack.js"></script>
<script src="../js/theme.js"></script>
</head>
<body class="wy-body-for-nav" role="document">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side stickynav">
<div class="wy-side-nav-search">
<a href=".." class="icon icon-home"> graphql-php</a>
<div role="search">
<form id ="rtd-search-form" class="wy-form" action="../search.html" method="get">
<input type="text" name="q" placeholder="Search docs" />
</form>
</div>
</div>
<div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
<ul class="current">
<li>
<li class="toctree-l1 ">
<a class="" href="..">About</a>
</li>
<li>
<li>
<li class="toctree-l1 ">
<a class="" href="../getting-started/">Getting Started</a>
</li>
<li>
<li>
<ul class="subnav">
<li><span>Type System</span></li>
<li class="toctree-l1 current">
<a class="current" href="./">Introduction</a>
<ul>
<li class="toctree-l3"><a href="#type-system">Type System</a></li>
<li class="toctree-l3"><a href="#type-definition-styles">Type Definition Styles</a></li>
<li class="toctree-l3"><a href="#type-registry">Type Registry</a></li>
</ul>
</li>
<li class="toctree-l1 ">
<a class="" href="object-types/">Object Types</a>
</li>
<li class="toctree-l1 ">
<a class="" href="scalar-types/">Scalar Types</a>
</li>
<li class="toctree-l1 ">
<a class="" href="enum-types/">Enumeration Types</a>
</li>
<li class="toctree-l1 ">
<a class="" href="lists-and-nonnulls/">Lists and Non-Null</a>
</li>
<li class="toctree-l1 ">
<a class="" href="interfaces/">Interfaces</a>
</li>
<li class="toctree-l1 ">
<a class="" href="unions/">Unions</a>
</li>
<li class="toctree-l1 ">
<a class="" href="input-types/">Input Types</a>
</li>
<li class="toctree-l1 ">
<a class="" href="directives/">Directives</a>
</li>
<li class="toctree-l1 ">
<a class="" href="schema/">Schema</a>
</li>
</ul>
<li>
<li>
<li class="toctree-l1 ">
<a class="" href="../executing-queries/">Executing Queries</a>
</li>
<li>
<li>
<li class="toctree-l1 ">
<a class="" href="../error-handling/">Handling Errors</a>
</li>
<li>
<li>
<li class="toctree-l1 ">
<a class="" href="../data-fetching/">Fetching Data</a>
</li>
<li>
<li>
<li class="toctree-l1 ">
<a class="" href="../best-practices/">Best Practices</a>
</li>
<li>
<li>
<li class="toctree-l1 ">
<a class="" href="../complementary-tools/">Complementary Tools</a>
</li>
<li>
</ul>
</div>
&nbsp;
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
<nav class="wy-nav-top" role="navigation" aria-label="top navigation">
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="..">graphql-php</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content">
<div role="navigation" aria-label="breadcrumbs navigation">
<ul class="wy-breadcrumbs">
<li><a href="..">Docs</a> &raquo;</li>
<li>Type System &raquo;</li>
<li>Introduction</li>
<li class="wy-breadcrumbs-aside">
</li>
</ul>
<hr/>
</div>
<div role="main">
<div class="section">
<h1 id="type-system">Type System</h1>
<p>To start using GraphQL you are expected to implement a type hierarchy and expose it as <a href="../type-system/schema/">Schema</a>. </p>
<p>In <strong>graphql-php</strong> <code>type</code> is an instance of internal class from
<code>GraphQL\Type\Definition</code> namespace: <code>ScalarType</code>, <code>ObjectType</code>, <code>InterfaceType</code>,
<code>UnionType</code>, <code>InputObjectType</code> (or one of it's subclasses).</p>
<p>But most of the types in your schema will be <a href="../type-system/object-types/">object types</a>.</p>
<h1 id="type-definition-styles">Type Definition Styles</h1>
<p>Several styles of type definitions are supported depending on your preferences.</p>
<p>Inline definitions:</p>
<pre><code class="php">&lt;?php
namespace MyApp;
use GraphQL\Type\Definition\ObjectType;
use GraphQL\Type\Definition\Type;
$myType = new ObjectType([
'name' =&gt; 'MyType',
'fields' =&gt; [
'id' =&gt; Type::id()
]
]);
</code></pre>
<p>Class per type, using inheritance:</p>
<pre><code class="php">&lt;?php
namespace MyApp;
use GraphQL\Type\Definition\ObjectType;
use GraphQL\Type\Definition\Type;
class MyType extends ObjectType
{
public function __construct()
{
$config = [
// Note: 'name' is not needed in this form:
// it will be inferred from class name by omitting namespace and dropping &quot;Type&quot; suffix
'fields' =&gt; [
'id' =&gt; Type::id()
]
];
parent::__construct($config);
}
}
</code></pre>
<p>Class per type, using composition:</p>
<pre><code class="php">&lt;?php
namespace MyApp;
use GraphQL\Type\Definition\ObjectType;
use GraphQL\Type\Definition\Type;
use GraphQL\Type\DefinitionContainer;
class MyType implements DefinitionContainer
{
private $definition;
public function getDefinition()
{
return $this-&gt;definition ?: ($this-&gt;definition = new ObjectType([
'name' =&gt; 'MyType',
'fields' =&gt; [
'id' =&gt; Type::id()
]
]));
}
}
</code></pre>
<p>You can also mix-and-match styles for convenience. For example:</p>
<pre><code class="php">&lt;?php
namespace MyApp;
use GraphQL\Type\Definition\ObjectType;
use GraphQL\Type\Definition\Type;
class BlogPostType extends ObjectType
{
public function __construct()
{
$config = [
'fields' =&gt; [
'body' =&gt; new ObjectType([
'name' =&gt; 'BlogPostBody',
'fields' =&gt; [
'html' =&gt; Type::string(),
'text' =&gt; Type::string(),
]
])
]
];
parent::__construct($config);
}
}
</code></pre>
<h1 id="type-registry">Type Registry</h1>
<p>Every type must be presented in Schema with single instance (<strong>graphql-php</strong>
throws when it discovers several instances with the same <code>name</code> in schema).</p>
<p>Therefore if you define your type as separate PHP class you must ensure that only one
instance of that class is added to schema.</p>
<p>Typical way to do this is to create registry of your types:</p>
<pre><code class="php">&lt;?php
namespace MyApp;
class TypeRegistry
{
private $myAType;
private $myBType;
public function myAType()
{
return $this-&gt;myAType ?: ($this-&gt;myAType = new MyAType($this));
}
public function myBType()
{
return $this-&gt;myBType ?: ($this-&gt;myBType = new MyBType($this));
}
}
</code></pre>
<p>And use this registry in type definition:</p>
<pre><code class="php">&lt;?php
namespace MyApp;
use GraphQL\Type\Definition\ObjectType;
class MyAType extends ObjectType
{
public function __construct(TypeRegistry $types)
{
parent::__construct([
'fields' =&gt; [
'b' =&gt; $types-&gt;myBType()
]
]);
}
}
</code></pre>
<p>Obviously you can automate this registry as you wish to reduce boilerplate or even
introduce Dependency Injection Container if your types have other dependencies.</p>
<p>Alternatively all methods of registry could be static if you prefer - then there is no need
to pass it in constructor - instead just use use <code>TypeRegistry::myAType()</code> in your type definitions.</p>
</div>
</div>
<footer>
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
<a href="object-types/" class="btn btn-neutral float-right" title="Object Types">Next <span class="icon icon-circle-arrow-right"></span></a>
<a href="../getting-started/" class="btn btn-neutral" title="Getting Started"><span class="icon icon-circle-arrow-left"></span> Previous</a>
</div>
<hr/>
<div role="contentinfo">
<!-- Copyright etc -->
</div>
Built with <a href="http://www.mkdocs.org">MkDocs</a> using a <a href="https://github.com/snide/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
</footer>
</div>
</div>
</section>
</div>
<div class="rst-versions" role="note" style="cursor: pointer">
<span class="rst-current-version" data-toggle="rst-current-version">
<span><a href="../getting-started/" style="color: #fcfcfc;">&laquo; Previous</a></span>
<span style="margin-left: 15px"><a href="object-types/" style="color: #fcfcfc">Next &raquo;</a></span>
</span>
</div>
</body>
</html>