reitit/ring/default_handler.html

902 lines
27 KiB
HTML
Raw Normal View History

<!DOCTYPE HTML>
<html lang="" >
<head>
<meta charset="UTF-8">
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
<title>Default handler · GitBook</title>
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="description" content="">
<meta name="generator" content="GitBook 3.2.3">
<link rel="stylesheet" href="../gitbook/style.css">
<link rel="stylesheet" href="../gitbook/gitbook-plugin-highlight/website.css">
<link rel="stylesheet" href="../gitbook/gitbook-plugin-search/search.css">
<link rel="stylesheet" href="../gitbook/gitbook-plugin-fontsettings/website.css">
<meta name="HandheldFriendly" content="true"/>
<meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
<meta name="apple-mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-status-bar-style" content="black">
<link rel="apple-touch-icon-precomposed" sizes="152x152" href="../gitbook/images/apple-touch-icon-precomposed-152.png">
<link rel="shortcut icon" href="../gitbook/images/favicon.ico" type="image/x-icon">
<link rel="next" href="static.html" />
<link rel="prev" href="reverse_routing.html" />
</head>
<body>
<div class="book">
<div class="book-summary">
<div id="book-search-input" role="search">
<input type="text" placeholder="Type to search" />
</div>
<nav role="navigation">
<ul class="summary">
<li class="chapter " data-level="1.1" data-path="../">
<a href="../">
Introduction
</a>
</li>
<li class="chapter " data-level="1.2" data-path="../basics/">
<a href="../basics/">
Basics
</a>
<ul class="articles">
<li class="chapter " data-level="1.2.1" data-path="../basics/route_syntax.html">
<a href="../basics/route_syntax.html">
Route Syntax
</a>
</li>
<li class="chapter " data-level="1.2.2" data-path="../basics/router.html">
<a href="../basics/router.html">
Router
</a>
</li>
<li class="chapter " data-level="1.2.3" data-path="../basics/path_based_routing.html">
<a href="../basics/path_based_routing.html">
Path-based Routing
</a>
</li>
<li class="chapter " data-level="1.2.4" data-path="../basics/name_based_routing.html">
<a href="../basics/name_based_routing.html">
Name-based Routing
</a>
</li>
<li class="chapter " data-level="1.2.5" data-path="../basics/route_data.html">
<a href="../basics/route_data.html">
Route Data
</a>
</li>
<li class="chapter " data-level="1.2.6" data-path="../basics/route_data_validation.html">
<a href="../basics/route_data_validation.html">
Route Data Validation
</a>
</li>
<li class="chapter " data-level="1.2.7" data-path="../basics/route_conflicts.html">
<a href="../basics/route_conflicts.html">
Route Conflicts
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="1.3" data-path="../coercion/">
<a href="../coercion/">
Coercion
</a>
<ul class="articles">
<li class="chapter " data-level="1.3.1" data-path="../coercion/coercion.html">
<a href="../coercion/coercion.html">
Coercion Explained
</a>
</li>
<li class="chapter " data-level="1.3.2" data-path="../coercion/schema_coercion.html">
<a href="../coercion/schema_coercion.html">
Plumatic Schema
</a>
</li>
<li class="chapter " data-level="1.3.3" data-path="../coercion/clojure_spec_coercion.html">
<a href="../coercion/clojure_spec_coercion.html">
Clojure.spec
</a>
</li>
<li class="chapter " data-level="1.3.4" data-path="../coercion/data_spec_coercion.html">
<a href="../coercion/data_spec_coercion.html">
Data-specs
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="1.4" data-path="./">
<a href="./">
Ring
</a>
<ul class="articles">
<li class="chapter " data-level="1.4.1" data-path="ring.html">
<a href="ring.html">
Ring-router
</a>
</li>
<li class="chapter " data-level="1.4.2" data-path="reverse_routing.html">
<a href="reverse_routing.html">
Reverse-routing
</a>
</li>
<li class="chapter active" data-level="1.4.3" data-path="default_handler.html">
<a href="default_handler.html">
Default handler
</a>
</li>
<li class="chapter " data-level="1.4.4" data-path="static.html">
<a href="static.html">
Static Resources
</a>
</li>
<li class="chapter " data-level="1.4.5" data-path="dynamic_extensions.html">
<a href="dynamic_extensions.html">
Dynamic Extensions
</a>
</li>
<li class="chapter " data-level="1.4.6" data-path="data_driven_middleware.html">
<a href="data_driven_middleware.html">
Data-driven Middleware
</a>
</li>
<li class="chapter " data-level="1.4.7" data-path="transforming_middleware_chain.html">
<a href="transforming_middleware_chain.html">
Transforming Middleware Chain
</a>
</li>
<li class="chapter " data-level="1.4.8" data-path="middleware_registry.html">
<a href="middleware_registry.html">
Middleware Registry
</a>
</li>
<li class="chapter " data-level="1.4.9" data-path="default_middleware.html">
<a href="default_middleware.html">
Default Middleware
</a>
</li>
<li class="chapter " data-level="1.4.10" data-path="coercion.html">
<a href="coercion.html">
Pluggable Coercion
</a>
</li>
<li class="chapter " data-level="1.4.11" data-path="route_data_validation.html">
<a href="route_data_validation.html">
Route Data Validation
</a>
</li>
<li class="chapter " data-level="1.4.12" data-path="compiling_middleware.html">
<a href="compiling_middleware.html">
Compiling Middleware
</a>
</li>
<li class="chapter " data-level="1.4.13" data-path="swagger.html">
<a href="swagger.html">
Swagger Support
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="1.5" data-path="../advanced/">
<a href="../advanced/">
Advanced
</a>
<ul class="articles">
<li class="chapter " data-level="1.5.1" data-path="../advanced/configuring_routers.html">
<a href="../advanced/configuring_routers.html">
Configuring Routers
</a>
</li>
<li class="chapter " data-level="1.5.2" data-path="../advanced/composing_routers.html">
<a href="../advanced/composing_routers.html">
Composing Routers
</a>
</li>
<li class="chapter " data-level="1.5.3" data-path="../advanced/different_routers.html">
<a href="../advanced/different_routers.html">
Different Routers
</a>
</li>
<li class="chapter " data-level="1.5.4" data-path="../advanced/route_validation.html">
<a href="../advanced/route_validation.html">
Route Validation
</a>
</li>
<li class="chapter " data-level="1.5.5" data-path="../advanced/dev_workflow.html">
<a href="../advanced/dev_workflow.html">
Dev Workflow
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="1.6" data-path="../patterns/">
<a href="../patterns/">
Patterns
</a>
<ul class="articles">
<li class="chapter " data-level="1.6.1" data-path="../patterns/shared_routes.html">
<a href="../patterns/shared_routes.html">
Shared Routes
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="1.7" data-path="../frontend/">
<a href="../frontend/">
Frontend
</a>
<ul class="articles">
<li class="chapter " data-level="1.7.1" data-path="../frontend/basics.html">
<a href="../frontend/basics.html">
Basics
</a>
</li>
<li class="chapter " data-level="1.7.2" data-path="../frontend/browser.html">
<a href="../frontend/browser.html">
Browser integration
</a>
</li>
<li class="chapter " data-level="1.7.3" data-path="../frontend/controllers.html">
<a href="../frontend/controllers.html">
Controllers (WIP)
</a>
</li>
</ul>
</li>
<li class="chapter " data-level="1.8" data-path="../performance.html">
<a href="../performance.html">
Performance
</a>
</li>
<li class="chapter " data-level="1.9" data-path="../interceptors.html">
<a href="../interceptors.html">
Interceptors (WIP)
</a>
</li>
<li class="chapter " data-level="1.10" data-path="../development.html">
<a href="../development.html">
Development Instructions
</a>
</li>
<li class="chapter " data-level="1.11" data-path="../faq.html">
<a href="../faq.html">
FAQ
</a>
</li>
<li class="divider"></li>
<li>
<a href="https://www.gitbook.com" target="blank" class="gitbook-link">
Published with GitBook
</a>
</li>
</ul>
</nav>
</div>
<div class="book-body">
<div class="body-inner">
<div class="book-header" role="navigation">
<!-- Title -->
<h1>
<i class="fa fa-circle-o-notch fa-spin"></i>
<a href=".." >Default handler</a>
</h1>
</div>
<div class="page-wrapper" tabindex="-1" role="main">
<div class="page-inner">
<div id="book-search-results">
<div class="search-noresults">
<section class="normal markdown-section">
<h1 id="default-handler">Default handler</h1>
<p>By default, if no routes match, <code>nil</code> is returned, which is not valid response in Ring:</p>
<pre><code class="lang-clj">(<span class="hljs-name">require</span> &apos;[reitit.ring <span class="hljs-symbol">:as</span> ring])
(<span class="hljs-name"><span class="hljs-builtin-name">defn</span></span> handler [_]
{<span class="hljs-symbol">:status</span> <span class="hljs-number">200</span>, <span class="hljs-symbol">:body</span> <span class="hljs-string">&quot;&quot;</span>})
(<span class="hljs-name"><span class="hljs-builtin-name">def</span></span> app
(<span class="hljs-name">ring/ring-handler</span>
(<span class="hljs-name">ring/router</span>
[<span class="hljs-string">&quot;/ping&quot;</span> handler])))
(<span class="hljs-name">app</span> {<span class="hljs-symbol">:uri</span> <span class="hljs-string">&quot;/invalid&quot;</span>})
<span class="hljs-comment">; nil</span>
</code></pre>
<p>Setting the default-handler as a second argument to <code>ring-handler</code>:</p>
<pre><code class="lang-clj">(<span class="hljs-name"><span class="hljs-builtin-name">def</span></span> app
(<span class="hljs-name">ring/ring-handler</span>
(<span class="hljs-name">ring/router</span>
[<span class="hljs-string">&quot;/ping&quot;</span> handler])
(<span class="hljs-name"><span class="hljs-builtin-name">constantly</span></span> {<span class="hljs-symbol">:status</span> <span class="hljs-number">404</span>, <span class="hljs-symbol">:body</span> <span class="hljs-string">&quot;&quot;</span>})))
(<span class="hljs-name">app</span> {<span class="hljs-symbol">:uri</span> <span class="hljs-string">&quot;/invalid&quot;</span>})
<span class="hljs-comment">; {:status 404, :body &quot;&quot;}</span>
</code></pre>
<p>To get more correct http error responses, <code>ring/create-default-handler</code> can be used. It differentiates <code>:not-found</code> (no route matched), <code>:method-not-accepted</code> (no method matched) and <code>:not-acceptable</code> (handler returned <code>nil</code>).</p>
<p>With defaults:</p>
<pre><code class="lang-clj">(<span class="hljs-name"><span class="hljs-builtin-name">def</span></span> app
(<span class="hljs-name">ring/ring-handler</span>
(<span class="hljs-name">ring/router</span>
[[<span class="hljs-string">&quot;/ping&quot;</span> {<span class="hljs-symbol">:get</span> handler}]
[<span class="hljs-string">&quot;/pong&quot;</span> (<span class="hljs-name"><span class="hljs-builtin-name">constantly</span></span> <span class="hljs-literal">nil</span>)]])
(<span class="hljs-name">ring/create-default-handler</span>)))
(<span class="hljs-name">app</span> {<span class="hljs-symbol">:request-method</span> <span class="hljs-symbol">:get</span>, <span class="hljs-symbol">:uri</span> <span class="hljs-string">&quot;/ping&quot;</span>})
<span class="hljs-comment">; {:status 200, :body &quot;&quot;}</span>
(<span class="hljs-name">app</span> {<span class="hljs-symbol">:request-method</span> <span class="hljs-symbol">:get</span>, <span class="hljs-symbol">:uri</span> <span class="hljs-string">&quot;/&quot;</span>})
<span class="hljs-comment">; {:status 404, :body &quot;&quot;}</span>
(<span class="hljs-name">app</span> {<span class="hljs-symbol">:request-method</span> <span class="hljs-symbol">:post</span>, <span class="hljs-symbol">:uri</span> <span class="hljs-string">&quot;/ping&quot;</span>})
<span class="hljs-comment">; {:status 405, :body &quot;&quot;}</span>
(<span class="hljs-name">app</span> {<span class="hljs-symbol">:request-method</span> <span class="hljs-symbol">:get</span>, <span class="hljs-symbol">:uri</span> <span class="hljs-string">&quot;/pong&quot;</span>})
<span class="hljs-comment">; {:status 406, :body &quot;&quot;}</span>
</code></pre>
<p>With custom responses:</p>
<pre><code class="lang-clj">(<span class="hljs-name"><span class="hljs-builtin-name">def</span></span> app
(<span class="hljs-name">ring/ring-handler</span>
(<span class="hljs-name">ring/router</span>
[[<span class="hljs-string">&quot;/ping&quot;</span> {<span class="hljs-symbol">:get</span> handler}]
[<span class="hljs-string">&quot;/pong&quot;</span> (<span class="hljs-name"><span class="hljs-builtin-name">constantly</span></span> <span class="hljs-literal">nil</span>)]])
(<span class="hljs-name">ring/create-default-handler</span>
{<span class="hljs-symbol">:not-found</span> (<span class="hljs-name"><span class="hljs-builtin-name">constantly</span></span> {<span class="hljs-symbol">:status</span> <span class="hljs-number">404</span>, <span class="hljs-symbol">:body</span> <span class="hljs-string">&quot;kosh&quot;</span>})
<span class="hljs-symbol">:method-not-allowed</span> (<span class="hljs-name"><span class="hljs-builtin-name">constantly</span></span> {<span class="hljs-symbol">:status</span> <span class="hljs-number">405</span>, <span class="hljs-symbol">:body</span> <span class="hljs-string">&quot;kosh&quot;</span>})
<span class="hljs-symbol">:not-acceptable</span> (<span class="hljs-name"><span class="hljs-builtin-name">constantly</span></span> {<span class="hljs-symbol">:status</span> <span class="hljs-number">406</span>, <span class="hljs-symbol">:body</span> <span class="hljs-string">&quot;kosh&quot;</span>})})))
(<span class="hljs-name">app</span> {<span class="hljs-symbol">:request-method</span> <span class="hljs-symbol">:get</span>, <span class="hljs-symbol">:uri</span> <span class="hljs-string">&quot;/ping&quot;</span>})
<span class="hljs-comment">; {:status 200, :body &quot;&quot;}</span>
(<span class="hljs-name">app</span> {<span class="hljs-symbol">:request-method</span> <span class="hljs-symbol">:get</span>, <span class="hljs-symbol">:uri</span> <span class="hljs-string">&quot;/&quot;</span>})
<span class="hljs-comment">; {:status 404, :body &quot;kosh&quot;}</span>
(<span class="hljs-name">app</span> {<span class="hljs-symbol">:request-method</span> <span class="hljs-symbol">:post</span>, <span class="hljs-symbol">:uri</span> <span class="hljs-string">&quot;/ping&quot;</span>})
<span class="hljs-comment">; {:status 405, :body &quot;kosh&quot;}</span>
(<span class="hljs-name">app</span> {<span class="hljs-symbol">:request-method</span> <span class="hljs-symbol">:get</span>, <span class="hljs-symbol">:uri</span> <span class="hljs-string">&quot;/pong&quot;</span>})
<span class="hljs-comment">; {:status 406, :body &quot;kosh&quot;}</span>
</code></pre>
</section>
</div>
<div class="search-results">
<div class="has-results">
<h1 class="search-results-title"><span class='search-results-count'></span> results matching "<span class='search-query'></span>"</h1>
<ul class="search-results-list"></ul>
</div>
<div class="no-results">
<h1 class="search-results-title">No results matching "<span class='search-query'></span>"</h1>
</div>
</div>
</div>
</div>
</div>
</div>
<a href="reverse_routing.html" class="navigation navigation-prev " aria-label="Previous page: Reverse-routing">
<i class="fa fa-angle-left"></i>
</a>
<a href="static.html" class="navigation navigation-next " aria-label="Next page: Static Resources">
<i class="fa fa-angle-right"></i>
</a>
</div>
<script>
var gitbook = gitbook || [];
gitbook.push(function() {
gitbook.page.hasChanged({"page":{"title":"Default handler","level":"1.4.3","depth":2,"next":{"title":"Static Resources","level":"1.4.4","depth":2,"path":"ring/static.md","ref":"ring/static.md","articles":[]},"previous":{"title":"Reverse-routing","level":"1.4.2","depth":2,"path":"ring/reverse_routing.md","ref":"ring/reverse_routing.md","articles":[]},"dir":"ltr"},"config":{"plugins":["editlink","github","highlight"],"root":"doc","styles":{"website":"styles/website.css","pdf":"styles/pdf.css","epub":"styles/epub.css","mobi":"styles/mobi.css","ebook":"styles/ebook.css","print":"styles/print.css"},"pluginsConfig":{"editlink":{"label":"Edit This Page","multilingual":false,"base":"https://github.com/metosin/reitit/tree/master/doc"},"github":{"url":"https://github.com/metosin/reitit"},"highlight":{},"search":{},"lunr":{"maxIndexSize":1000000,"ignoreSpecialCharacters":false},"sharing":{"facebook":true,"twitter":true,"google":false,"weibo":false,"instapaper":false,"vk":false,"all":["facebook","google","twitter","weibo","instapaper"]},"fontsettings":{"theme":"white","family":"sans","size":2},"theme-default":{"styles":{"website":"styles/website.css","pdf":"styles/pdf.css","epub":"styles/epub.css","mobi":"styles/mobi.css","ebook":"styles/ebook.css","print":"styles/print.css"},"showLevel":false}},"theme":"default","pdf":{"pageNumbers":true,"fontSize":12,"fontFamily":"Arial","paperSize":"a4","chapterMark":"pagebreak","pageBreaksBefore":"/","margin":{"right":62,"left":62,"top":56,"bottom":56}},"structure":{"langs":"LANGS.md","readme":"README.md","glossary":"GLOSSARY.md","summary":"SUMMARY.md"},"variables":{},"gitbook":"*"},"file":{"path":"ring/default_handler.md","mtime":"2018-08-31T08:17:50.400Z","type":"markdown"},"gitbook":{"version":"3.2.3","time":"2018-08-31T08:18:32.313Z"},"basePath":"..","book":{"language":""}});
});
</script>
</div>
<script src="../gitbook/gitbook.js"></script>
<script src="../gitbook/theme.js"></script>
<script src="../gitbook/gitbook-plugin-editlink/plugin.js"></script>
<script src="../gitbook/gitbook-plugin-github/plugin.js"></script>
<script src="../gitbook/gitbook-plugin-search/search-engine.js"></script>
<script src="../gitbook/gitbook-plugin-search/search.js"></script>
<script src="../gitbook/gitbook-plugin-lunr/lunr.min.js"></script>
<script src="../gitbook/gitbook-plugin-lunr/search-lunr.js"></script>
<script src="../gitbook/gitbook-plugin-sharing/buttons.js"></script>
<script src="../gitbook/gitbook-plugin-fontsettings/fontsettings.js"></script>
</body>
</html>