API:Allcategories

This page is part of the MediaWiki Action API documentation.

MediaWiki version:

≥ 1.12

GET request to list all categories that fit certain criteria relating to their titles.

This module can be used as a generator .

API documentation

The following documentation is the output of Special:ApiHelp/query+allcategories, automatically generated by the pre-release version of MediaWiki that is running on this site (MediaWiki.org).

list=allcategories (ac)

(main | query | allcategories)

This module requires read rights.
This module can be used as a generator.
Source: MediaWiki
License: GPL-2.0-or-later

Enumerate all categories.

https://www.mediawiki.org/wiki/Special:MyLanguage/API:Allcategories

Specific parameters:

Other general parameters are available.

acfrom

The category to start enumerating from.

accontinue

When more results are available, use this to continue. More detailed information on how to continue queries can be found on mediawiki.org.

acto

The category to stop enumerating at.

acprefix

Search for all category titles that begin with this value.

acdir

Direction to sort in.

One of the following values: ascending, descending

Default: ascending

acmin

Only return categories with at least this many members.

Type: integer

acmax

Only return categories with at most this many members.

Type: integer

aclimit

How many categories to return.

Type: integer or max

The value must be between 1 and 500.

Default: 10

acprop

Which properties to get:

size: Adds number of pages in the category.
hidden: Tags categories that are hidden with __HIDDENCAT__.

Values (separate with | or alternative): hidden, size

Default: (empty)

Examples:

List categories with information on the number of pages in each.: api.php?action=query&list=allcategories&acprop=size [open in sandbox]
Retrieve info about the category page itself for categories beginning List.: api.php?action=query&generator=allcategories&gacprefix=List&prop=info [open in sandbox]

Example

GET request

Get a list of all categories, starting from "15th-century caliphs".

api.php?action=query&format=json&acfrom=15th-century%20caliphs&list=allcategories [try in ApiSandbox]

Response

{
    {
    "batchcomplete": "",
    "continue": {
        "accontinue": "15th-century_churches_in_Denmark",
        "continue": "-||"
    },
    "query": {
        "allcategories": [
            {
                "*": "15th-century caliphs"
            },
            {
                "*": "15th-century calligraphers"
            },
            {
                "*": "15th-century card games"
            },
            ...
        ]
    }
}

Sample code

Python

#!/usr/bin/python3

"""
    get_allcategories.py

    MediaWiki API Demos
    Demo of `Allcategories` module: Get all categories, starting from a
    certain point, as ordered by category title.

    MIT License
"""

import requests

S = requests.Session()

URL = "https://en.wikipedia.org/w/api.php"

PARAMS = {
    "action": "query",
    "format": "json",
    "list": "allcategories",
    "acfrom": "15th-century caliphs"
}

R = S.get(url=URL, params=PARAMS)
DATA = R.json()

CATEGORIES = DATA["query"]["allcategories"]

for cat in CATEGORIES:
    print(cat["*"])

PHP

<?php
/*
    get_allcategories.php

    MediaWiki API Demos
    Demo of `Allcategories` module: Get all categories, starting from a certian point, as ordered by category title.

    MIT License
*/

$endPoint = "https://en.wikipedia.org/w/api.php";
$params = [
    "action" => "query",
    "format" => "json",
    "list" => "allcategories",
    "acfrom" => "15th-century caliphs"
];

$url = $endPoint . "?" . http_build_query( $params );

$ch = curl_init( $url );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
$output = curl_exec( $ch );
curl_close( $ch );

$result = json_decode( $output, true );

foreach( $result["query"]["allcategories"] as $k => $v ) {
    echo( $v["*"] . "\n" );
}

JavaScript

/*
    get_allcategories.js

    MediaWiki API Demos
    Demo of `Allcategories` module: Get all categories, starting from a certain point, as ordered by category title.

    MIT License
*/

var url = "https://en.wikipedia.org/w/api.php"; 

var params = {
    action: "query",
    format: "json",
    list: "allcategories",
    acfrom: "15th-century caliphs"
};

url = url + "?origin=*";
Object.keys(params).forEach(function(key){url += "&" + key + "=" + params[key];});

fetch(url)
    .then(function(response){return response.json();})
    .then(function(response) {
        var categories = response.query.allcategories;
        for (var cat in categories) {
            console.log(categories[cat]["*"]);
        }
    })
    .catch(function(error){console.log(error);});

MediaWiki JS

/*
	get_allcategories.js

	MediaWiki API Demos
	Demo of `Allcategories` module: Get all categories,
	starting from a certian point, as ordered by category title.

	MIT License
*/

var params = {
		action: 'query',
		format: 'json',
		list: 'allcategories',
		acfrom: '15th-century caliphs'
	},
	api = new mw.Api();

api.get( params ).done( function ( data ) {
	var categories = data.query.allcategories,
		cat;
	for ( cat in categories ) {
		console.log( categories[ cat ][ '*' ] );
	}
} );

Additional notes

This module differs from list=allpages&alnamespace=14 in that categories without descriptions will be listed, while redirects and pages where the category was never used will not.
The response may include categories that were previously used but have since been deleted.
Because the response may include categories that are deleted or otherwise empty, it is recommended to filter the list using acmin=1, so as to only return categories containing one or more members.