juniper/master/advanced/introspection.html

271 lines
15 KiB
HTML
Raw Normal View History

2019-04-09 19:26:56 -05:00
<!DOCTYPE HTML>
2020-02-21 00:35:48 -06:00
<html lang="en" class="sidebar-visible no-js">
2019-04-09 19:26:56 -05:00
<head>
<!-- Book generated using mdBook -->
<meta charset="UTF-8">
<title>Introspection - Juniper - GraphQL Server for Rust</title>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
<meta name="description" content="Documentation for juniper, a GraphQL server library for Rust.">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="theme-color" content="#ffffff" />
<link rel="shortcut icon" href="../favicon.png">
<link rel="stylesheet" href="../css/variables.css">
<link rel="stylesheet" href="../css/general.css">
<link rel="stylesheet" href="../css/chrome.css">
<link rel="stylesheet" href="../css/print.css" media="print">
<!-- Fonts -->
<link rel="stylesheet" href="../FontAwesome/css/font-awesome.css">
<link href="https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800" rel="stylesheet" type="text/css">
<link href="https://fonts.googleapis.com/css?family=Source+Code+Pro:500" rel="stylesheet" type="text/css">
<!-- Highlight.js Stylesheets -->
<link rel="stylesheet" href="../highlight.css">
<link rel="stylesheet" href="../tomorrow-night.css">
<link rel="stylesheet" href="../ayu-highlight.css">
<!-- Custom theme stylesheets -->
</head>
2020-02-21 00:35:48 -06:00
<body class="light">
2019-04-09 19:26:56 -05:00
<!-- Provide site root to javascript -->
2020-02-21 00:35:48 -06:00
<script type="text/javascript">var path_to_root = "../";</script>
2019-04-09 19:26:56 -05:00
<!-- Work around some values being stored in localStorage wrapped in quotes -->
<script type="text/javascript">
try {
var theme = localStorage.getItem('mdbook-theme');
var sidebar = localStorage.getItem('mdbook-sidebar');
if (theme.startsWith('"') && theme.endsWith('"')) {
localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
}
if (sidebar.startsWith('"') && sidebar.endsWith('"')) {
localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
}
} catch (e) { }
</script>
<!-- Set the theme before any content is loaded, prevents flash -->
<script type="text/javascript">
var theme;
2020-02-21 00:35:48 -06:00
try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
if (theme === null || theme === undefined) { theme = 'light'; }
document.body.className = theme;
document.querySelector('html').className = theme + ' js';
2019-04-09 19:26:56 -05:00
</script>
<!-- Hide / unhide sidebar before it is displayed -->
<script type="text/javascript">
var html = document.querySelector('html');
var sidebar = 'hidden';
if (document.body.clientWidth >= 1080) {
try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
sidebar = sidebar || 'visible';
}
html.classList.remove('sidebar-visible');
html.classList.add("sidebar-" + sidebar);
</script>
<nav id="sidebar" class="sidebar" aria-label="Table of contents">
2020-04-17 01:25:26 -05:00
<ol class="chapter"><li class="affix"><a href="../index.html">Introduction</a></li><li class="affix"><a href="../quickstart.html">Quickstart</a></li><li class="affix"><a href="../types/index.html">Type System</a></li><li><a href="../types/objects/defining_objects.html"><strong aria-hidden="true">1.</strong> Defining objects</a></li><li><ol class="section"><li><a href="../types/objects/complex_fields.html"><strong aria-hidden="true">1.1.</strong> Complex fields</a></li><li><a href="../types/objects/using_contexts.html"><strong aria-hidden="true">1.2.</strong> Using contexts</a></li><li><a href="../types/objects/error_handling.html"><strong aria-hidden="true">1.3.</strong> Error handling</a></li></ol></li><li><a href="../types/other-index.html"><strong aria-hidden="true">2.</strong> Other types</a></li><li><ol class="section"><li><a href="../types/enums.html"><strong aria-hidden="true">2.1.</strong> Enums</a></li><li><a href="../types/interfaces.html"><strong aria-hidden="true">2.2.</strong> Interfaces</a></li><li><a href="../types/input_objects.html"><strong aria-hidden="true">2.3.</strong> Input objects</a></li><li><a href="../types/scalars.html"><strong aria-hidden="true">2.4.</strong> Scalars</a></li><li><a href="../types/unions.html"><strong aria-hidden="true">2.5.</strong> Unions</a></li></ol></li><li><a href="../schema/schemas_and_mutations.html"><strong aria-hidden="true">3.</strong> Schemas and mutations</a></li><li><a href="../servers/index.html"><strong aria-hidden="true">4.</strong> Adding A Server</a></li><li><ol class="section"><li><a href="../servers/official.html"><strong aria-hidden="true">4.1.</strong> Official Server Integrations</a></li><li><ol class="section"><li><a href="../servers/warp.html"><strong aria-hidden="true">4.1.1.</strong> Warp</a></li><li><a href="../servers/rocket.html"><strong aria-hidden="true">4.1.2.</strong> Rocket</a></li><li><a href="../servers/iron.html"><strong aria-hidden="true">4.1.3.</strong> Iron</a></li><li><a href="../servers/hyper.html"><strong aria-hidden="true">4.1.4.</strong> Hyper</a></li></ol></li><li><a href="../servers/third-party.html"><strong aria-hidden="true">4.2.</strong> Third Party Integrations</a></li></ol></li><li><a href="../advanced/index.html"><strong aria-hidden="true">5.</strong> Advanced Topics</a></li><li><ol class="section"><li><a href="../advanced/introspection.html" class="active"><strong aria-hidden="true">5.1.</strong> Introspection</a></li><li><a href="../advanced/non_struct_objects.html"><strong aria-hidden="true">5.2.</strong> Non-struct objects</a></li><li><a href="../advanced/objects_and_generics.html"><strong aria-hidden="true">5.3.</strong> Objects and generics</a></li><li><a href="../advanced/multiple_ops_per_request.html"><strong aria-hidden="true">5.4.</strong> Multiple operations per request</a></li><li><a href="../advanced/dataloaders.html"><strong aria-hidden="true">5.5.</strong> Dataloaders</a></li><li><a href="../advanced/subscriptions.html"><strong aria-hidden="true">5.6.</strong> Subscriptions</a></li></ol></li></ol>
2019-04-09 19:26:56 -05:00
</nav>
<div id="page-wrapper" class="page-wrapper">
<div class="page">
<div id="menu-bar" class="menu-bar">
<div id="menu-bar-sticky-container">
<div class="left-buttons">
<button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
<i class="fa fa-bars"></i>
</button>
<button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
<i class="fa fa-paint-brush"></i>
</button>
<ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
2020-02-21 00:35:48 -06:00
<li role="none"><button role="menuitem" class="theme" id="light">Light <span class="default">(default)</span></button></li>
2019-04-09 19:26:56 -05:00
<li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
<li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
<li role="none"><button role="menuitem" class="theme" id="navy">Navy</button></li>
<li role="none"><button role="menuitem" class="theme" id="ayu">Ayu</button></li>
</ul>
<button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar">
<i class="fa fa-search"></i>
</button>
</div>
2020-02-21 00:35:48 -06:00
<h1 class="menu-title">Juniper - GraphQL Server for Rust</h1>
2019-04-09 19:26:56 -05:00
<div class="right-buttons">
<a href="../print.html" title="Print this book" aria-label="Print this book">
<i id="print-button" class="fa fa-print"></i>
</a>
</div>
</div>
</div>
<div id="search-wrapper" class="hidden">
<form id="searchbar-outer" class="searchbar-outer">
<input type="search" name="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
</form>
<div id="searchresults-outer" class="searchresults-outer hidden">
<div id="searchresults-header" class="searchresults-header"></div>
<ul id="searchresults">
</ul>
</div>
</div>
<!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
<script type="text/javascript">
document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
});
</script>
<div id="content" class="content">
<main>
2020-02-21 00:35:48 -06:00
<a class="header" href="#introspection" id="introspection"><h1>Introspection</h1></a>
2019-04-09 19:26:56 -05:00
<p>GraphQL defines a special built-in top-level field called <code>__schema</code>. Querying
for this field allows one to <a href="https://graphql.org/learn/introspection/">introspect the schema</a>
at runtime to see what queries and mutations the GraphQL server supports.</p>
<p>Because introspection queries are just regular GraphQL queries, Juniper supports
them natively. For example, to get all the names of the types supported one
could execute the following query against Juniper:</p>
<pre><code class="language-graphql">{
__schema {
types {
name
}
}
}
</code></pre>
2020-02-21 00:35:48 -06:00
<a class="header" href="#schema-introspection-output-as-json" id="schema-introspection-output-as-json"><h2>Schema introspection output as JSON</h2></a>
2019-04-09 19:26:56 -05:00
<p>Many client libraries and tools in the GraphQL ecosystem require a complete
representation of the server schema. Often this representation is in JSON and
referred to as <code>schema.json</code>. A complete representation of the schema can be
produced by issuing a specially crafted introspection query.</p>
<p>Juniper provides a convenience function to introspect the entire schema. The
result can then be converted to JSON for use with tools and libraries such as
<a href="https://github.com/graphql-rust/graphql-client">graphql-client</a>:</p>
2020-07-18 20:35:25 -05:00
<pre><pre class="playpen"><code class="language-rust"># extern crate juniper;
# extern crate serde_json;
use juniper::{EmptyMutation, EmptySubscription, FieldResult, IntrospectionFormat};
2019-04-09 19:26:56 -05:00
// Define our schema.
#[derive(juniper::GraphQLObject)]
struct Example {
id: String,
}
struct Context;
impl juniper::Context for Context {}
struct Query;
#[juniper::graphql_object(
2019-05-14 01:52:54 -05:00
Context = Context,
)]
impl Query {
fn example(id: String) -&gt; FieldResult&lt;Example&gt; {
2019-04-09 19:26:56 -05:00
unimplemented!()
}
2019-05-14 01:52:54 -05:00
}
2019-04-09 19:26:56 -05:00
2020-03-18 22:40:03 -05:00
type Schema = juniper::RootNode&lt;
'static,
Query,
EmptyMutation&lt;Context&gt;,
EmptySubscription&lt;Context&gt;
&gt;;
2019-04-09 19:26:56 -05:00
fn main() {
// Create a context object.
let ctx = Context{};
// Run the built-in introspection query.
let (res, _errors) = juniper::introspect(
2020-03-18 22:40:03 -05:00
&amp;Schema::new(Query, EmptyMutation::new(), EmptySubscription::new()),
2019-04-09 19:26:56 -05:00
&amp;ctx,
IntrospectionFormat::default(),
).unwrap();
// Convert introspection result to json.
let json_result = serde_json::to_string_pretty(&amp;res);
assert!(json_result.is_ok());
}
</code></pre></pre>
</main>
<nav class="nav-wrapper" aria-label="Page navigation">
<!-- Mobile navigation buttons -->
<a rel="prev" href="../advanced/index.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
<i class="fa fa-angle-left"></i>
</a>
<a rel="next" href="../advanced/non_struct_objects.html" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
<i class="fa fa-angle-right"></i>
</a>
<div style="clear: both"></div>
</nav>
</div>
</div>
<nav class="nav-wide-wrapper" aria-label="Page navigation">
<a href="../advanced/index.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
<i class="fa fa-angle-left"></i>
</a>
<a href="../advanced/non_struct_objects.html" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
<i class="fa fa-angle-right"></i>
</a>
</nav>
</div>
<script src="../elasticlunr.min.js" type="text/javascript" charset="utf-8"></script>
<script src="../mark.min.js" type="text/javascript" charset="utf-8"></script>
<script src="../searcher.js" type="text/javascript" charset="utf-8"></script>
<script src="../clipboard.min.js" type="text/javascript" charset="utf-8"></script>
<script src="../highlight.js" type="text/javascript" charset="utf-8"></script>
<script src="../book.js" type="text/javascript" charset="utf-8"></script>
<!-- Custom JS scripts -->
</body>
</html>