{"id":898,"date":"2013-07-11T07:58:39","date_gmt":"2013-07-10T21:58:39","guid":{"rendered":"http:\/\/makesomecode.com\/?p=898"},"modified":"2015-01-14T18:20:41","modified_gmt":"2015-01-14T18:20:41","slug":"etags-in-laravel-4","status":"publish","type":"post","link":"https:\/\/nickv.codes\/blog\/etags-in-laravel-4\/","title":{"rendered":"ETags in Laravel 4 using Filters"},"content":{"rendered":"<p>Laravel 4 has some very nice features in which you can build your api on. After reading about some best practices for REST many people suggest using ETags for validation caching. I&#8217;ve come up with a realtivley simple solution to enable ETag validation of your api data.<\/p>\n<p>I simply used a filter to catch the response after it was created, created an md5 hash of the content and compared it with ETag in the request. The code in my <code>app\/routes.php<\/code>\u00a0looks something like this:<\/p>\n<pre class=\"prettyprint lang-php\">Route::filter('etag', function($route, $request, $response){\r\n  $etag = md5($response-&gt;getContent());\r\n  $requestETag = str_replace('\"', '', $request-&gt;getETags());\r\n\r\n  if($requestETag &amp;&amp; $requestETag[0] == $etag){\r\n    $response-&gt;setNotModified();\r\n  }\r\n\r\n  $response-&gt;setEtag($etag);\r\n\r\n  return;\r\n});\r\n\r\nRoute::group(array(\r\n    'prefix'\t=&gt; 'api\/v1',\r\n    'after'\t=&gt; 'etag'\r\n  ),\r\n  function()\r\n  {\r\n    Route::resource('invoice', 'V1InvoicesController');\r\n  }\r\n);\r\n<\/pre>\n<p>Now when I fetch an invoice an Etag is generated, and compared with the one supplied in the request. If they match, the body is discarded and a 304 is sent back.<\/p>\n<p>This obviously has a few gotchas:<\/p>\n<ul>\n<li><span style=\"line-height: 13px;\">It will not lower any server load. In fact this might slightly increase load since you&#8217;ll be generating and comapring ETags on each request. This is simply a bandwidth saving solution for you and the client.<\/span><\/li>\n<li><span style=\"line-height: 13px;\">I&#8217;m hashing the entire body content. For some this might be\u00a0undesirable. As a minimum hash the data that you need to know if it changed since the last request.<\/span><\/li>\n<li>This doesn&#8217;t replace other caching methods like memcached, it&#8217;s meant to work along side it.<\/li>\n<\/ul>\n<p>References:<br \/>\n<a href=\"http:\/\/fideloper.com\/laravel4-etag-conditional-get\" target=\"_blank\">http:\/\/fideloper.com\/laravel4-etag-conditional-get<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Laravel 4 has some very nice features in which you can build your api on. After reading about some best practices for REST many people suggest using ETags for validation caching. I&#8217;ve come up with a realtivley simple solution to enable ETag validation of your api data. I simply used a filter to catch the [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[19,13],"tags":[40,62,80],"_links":{"self":[{"href":"https:\/\/nickv.codes\/wp-json\/wp\/v2\/posts\/898"}],"collection":[{"href":"https:\/\/nickv.codes\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nickv.codes\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nickv.codes\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/nickv.codes\/wp-json\/wp\/v2\/comments?post=898"}],"version-history":[{"count":0,"href":"https:\/\/nickv.codes\/wp-json\/wp\/v2\/posts\/898\/revisions"}],"wp:attachment":[{"href":"https:\/\/nickv.codes\/wp-json\/wp\/v2\/media?parent=898"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nickv.codes\/wp-json\/wp\/v2\/categories?post=898"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nickv.codes\/wp-json\/wp\/v2\/tags?post=898"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}