mirror of
https://github.com/MarshalX/telegram-crawler.git
synced 2024-11-28 19:23:11 +01:00
170 lines
9.3 KiB
HTML
170 lines
9.3 KiB
HTML
<!DOCTYPE html>
|
|
<html class="">
|
|
<head>
|
|
<meta charset="utf-8">
|
|
<title>Pagination in the API</title>
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
<meta property="description" content="How to fetch results from large lists of objects.">
|
|
<meta property="og:title" content="Pagination in the API">
|
|
<meta property="og:image" content="4dd378cd0f58b0b820">
|
|
<meta property="og:description" content="How to fetch results from large lists of objects.">
|
|
<link rel="shortcut icon" href="/favicon.ico?4" type="image/x-icon" />
|
|
|
|
<link href="/css/bootstrap.min.css?3" rel="stylesheet">
|
|
|
|
<link href="/css/telegram.css?215" rel="stylesheet" media="screen">
|
|
<style>
|
|
</style>
|
|
</head>
|
|
<body class="preload">
|
|
<div class="dev_page_wrap">
|
|
<div class="dev_page_head navbar navbar-static-top navbar-tg">
|
|
<div class="navbar-inner">
|
|
<div class="container clearfix">
|
|
<ul class="nav navbar-nav navbar-right hidden-xs"><li class="navbar-twitter"><a href="https://twitter.com/telegram" target="_blank" data-track="Follow/Twitter" onclick="trackDlClick(this, event)"><i class="icon icon-twitter"></i><span> Twitter</span></a></li></ul>
|
|
<ul class="nav navbar-nav">
|
|
<li><a href="//telegram.org/">Home</a></li>
|
|
<li class="hidden-xs"><a href="//telegram.org/faq">FAQ</a></li>
|
|
<li class="hidden-xs"><a href="//telegram.org/apps">Apps</a></li>
|
|
<li class="active"><a href="/api">API</a></li>
|
|
<li class=""><a href="/mtproto">Protocol</a></li>
|
|
<li class=""><a href="/schema">Schema</a></li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="container clearfix">
|
|
<div class="dev_page">
|
|
<div id="dev_page_content_wrap" class=" ">
|
|
<div class="dev_page_bread_crumbs"><ul class="breadcrumb clearfix"><li><a href="/api" >API</a></li><i class="icon icon-breadcrumb-divider"></i><li><a href="/api/offsets" >Pagination in the API</a></li></ul></div>
|
|
<h1 id="dev_page_title">Pagination in the API</h1>
|
|
|
|
<div id="dev_page_content"><!-- scroll_nav -->
|
|
|
|
<p>Lots of Telegram API methods provide access to potentially large lists of objects, which requires pagination.</p>
|
|
<p>In order to fetch only relevant subset of results for each request there is a number of available input parameters. Here is a list in order how they are applied in API.</p>
|
|
<p>Typically, results are returned in antichronological order with descending object ID values.</p>
|
|
<h3><a class="anchor" href="#limit-parameter" id="limit-parameter" name="limit-parameter"><i class="anchor-icon"></i></a><code>limit</code> parameter</h3>
|
|
<p>A limit on the number of objects to be returned, typically between 1 and 100. When 0 is provided the limit will often default to an intermediate value like ~20.</p>
|
|
<h3><a class="anchor" href="#offset-based-pagination" id="offset-based-pagination" name="offset-based-pagination"><i class="anchor-icon"></i></a><code>offset</code>-based pagination</h3>
|
|
<p>For a few methods with mostly static data this parameter allows to skip <code>offset</code> elements from the beginning of list; negative values are ignored.</p>
|
|
<h3><a class="anchor" href="#offset-id-based-pagination" id="offset-id-based-pagination" name="offset-id-based-pagination"><i class="anchor-icon"></i></a><code>offset_id</code>-based pagination</h3>
|
|
<p>For most methods where results are real-time data (e.g. any chat history) <code>offset</code> value is not passed directly. Instead it is calculated from the passed <code>offset_id</code> and <code>add_offset</code> parameter values as <code>offsetFromID(offset_id) + add_offset</code>, where <code>offsetFromID(offset_id)</code> is a number of results from the beginning of list up to the result with ID <code>offset_id</code>, inclusive.</p>
|
|
<p>Sample use cases:</p>
|
|
<ul>
|
|
<li>
|
|
<p>Loading 20 messages, older than message with ID <code>MSGID</code>:</p>
|
|
<p>messages.getHistory({offset_id: MSGID, add_offset: 0, limit: 20})</p>
|
|
</li>
|
|
<li>
|
|
<p>Loading 20 messages, newer than message with ID <code>MSGID</code>:</p>
|
|
<p>messages.getHistory({offset_id: MSGID, add_offset: -20, limit: 20})</p>
|
|
</li>
|
|
<li>
|
|
<p>Loading 20 messages around message with ID <code>MSGID</code>:</p>
|
|
<p>messages.getHistory({offset_id: MSGID, add_offset: -10, limit: 20})</p>
|
|
</li>
|
|
</ul>
|
|
<h3><a class="anchor" href="#additional-filtering" id="additional-filtering" name="additional-filtering"><i class="anchor-icon"></i></a>Additional filtering</h3>
|
|
<p>There is a number of parameters, which are applied to the list after slicing with offset and limit, to reduce the result subset even more:</p>
|
|
<ul>
|
|
<li><strong>max_id</strong>: Can be used to only return results with ID strictly smaller than <code>max_id</code> (e.g. message ID)</li>
|
|
<li><strong>min_id</strong>: Can be used to only return results with ID strictly greater than <code>min_id</code>(e.g. message ID)</li>
|
|
<li><strong>max_date</strong>: Can be used to only return results that are older than <code>max_date</code>:</li>
|
|
<li><strong>min_date</strong>: Can be used to only return results with are newer than <code>min_date</code>:</li>
|
|
<li><strong>hash</strong>: See below.</li>
|
|
</ul>
|
|
<h3><a class="anchor" href="#hash-generation" id="hash-generation" name="hash-generation"><i class="anchor-icon"></i></a>Hash generation</h3>
|
|
<p>To further reduce the result subset, there is a mechanism to avoid fetching data if the resulting list hasn't changed from the one stored on client, similar to <a href="https://en.wikipedia.org/wiki/HTTP_ETag">ETag</a>.</p>
|
|
<p>When the client has cached results for API request, it can calculate the <code>hash</code> value for it by taking the result IDs (message IDs or other fields with name <code>id</code>) and using them to compute a 64-bit hash with the following algorithm:</p>
|
|
<pre><code># Here, ^ indicates a bitwise XOR
|
|
|
|
hash = 0
|
|
for id in ids:
|
|
hash = hash ^ (id >> 21)
|
|
hash = hash ^ (id << 35)
|
|
hash = hash ^ (id >> 4)
|
|
hash = hash + id</code></pre>
|
|
<p>In some cases, the result container already has a <code>hash</code> field, that can be used instead.</p>
|
|
<p>When the client passes a correct value, the API will return one of <code>*NotModified</code> constructors, e.g. <a href="/constructor/messages.messagesNotModified">messages.messagesNotModified</a> instead of the actual results.</p>
|
|
<h3><a class="anchor" href="#example-methods" id="example-methods" name="example-methods"><i class="anchor-icon"></i></a>Example methods</h3>
|
|
<ul>
|
|
<li><a href="/method/messages.getHistory">messages.getHistory</a> supports all result navigation parameters including message ID hashes and except filters</li>
|
|
<li><a href="/method/channels.getParticipants">channels.getParticipants</a> supports simple navigation using <strong>limit</strong> and <strong>offset</strong>, along with filtering and <code>hash</code> reducing using the user IDs of returned participants</li>
|
|
</ul></div>
|
|
|
|
</div>
|
|
|
|
</div>
|
|
</div>
|
|
<div class="footer_wrap">
|
|
<div class="footer_columns_wrap footer_desktop">
|
|
<div class="footer_column footer_column_telegram">
|
|
<h5>Telegram</h5>
|
|
<div class="footer_telegram_description"></div>
|
|
Telegram is a cloud-based mobile and desktop messaging app with a focus on security and speed.
|
|
</div>
|
|
|
|
<div class="footer_column">
|
|
<h5><a href="//telegram.org/faq">About</a></h5>
|
|
<ul>
|
|
<li><a href="//telegram.org/faq">FAQ</a></li>
|
|
<li><a href="//telegram.org/blog">Blog</a></li>
|
|
<li><a href="//telegram.org/jobs">Jobs</a></li>
|
|
</ul>
|
|
</div>
|
|
<div class="footer_column">
|
|
<h5><a href="//telegram.org/apps#mobile-apps">Mobile Apps</a></h5>
|
|
<ul>
|
|
<li><a href="//telegram.org/dl/ios">iPhone/iPad</a></li>
|
|
<li><a href="//telegram.org/dl/android">Android</a></li>
|
|
<li><a href="//telegram.org/dl/wp">Windows Phone</a></li>
|
|
</ul>
|
|
</div>
|
|
<div class="footer_column">
|
|
<h5><a href="//telegram.org/apps#desktop-apps">Desktop Apps</a></h5>
|
|
<ul>
|
|
<li><a href="//desktop.telegram.org/">PC/Mac/Linux</a></li>
|
|
<li><a href="//macos.telegram.org/">macOS</a></li>
|
|
<li><a href="//telegram.org/dl/web">Web-browser</a></li>
|
|
</ul>
|
|
</div>
|
|
<div class="footer_column footer_column_platform">
|
|
<h5><a href="/">Platform</a></h5>
|
|
<ul>
|
|
<li><a href="/api">API</a></li>
|
|
<li><a href="//translations.telegram.org/">Translations</a></li>
|
|
<li><a href="//instantview.telegram.org/">Instant View</a></li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="footer_columns_wrap footer_mobile">
|
|
<div class="footer_column">
|
|
<h5><a href="//telegram.org/faq">About</a></h5>
|
|
</div>
|
|
<div class="footer_column">
|
|
<h5><a href="//telegram.org/blog">Blog</a></h5>
|
|
</div>
|
|
<div class="footer_column">
|
|
<h5><a href="//telegram.org/apps">Apps</a></h5>
|
|
</div>
|
|
<div class="footer_column">
|
|
<h5><a href="/">Platform</a></h5>
|
|
</div>
|
|
<div class="footer_column">
|
|
<h5><a href="https://twitter.com/telegram" target="_blank" data-track="Follow/Twitter" onclick="trackDlClick(this, event)">Twitter</a></h5>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<script src="/js/main.js?43"></script>
|
|
<script src="/js/jquery.min.js?1"></script>
|
|
<script src="/js/bootstrap.min.js?1"></script>
|
|
|
|
<script>window.initDevPageNav&&initDevPageNav();
|
|
backToTopInit("Go up");
|
|
removePreloadInit();
|
|
</script>
|
|
</body>
|
|
</html>
|
|
|