Introduction to ProcessWire API variables

ProcessWire provides various API variables to every template file. These variables provide full access to all site content. This page provides an introduction on how to use them.

API variables can be accessed in a few different ways. The most common way is as a variable. Here are a few different ways you might access the same $page API variable (as an example):

  • $page the most common access as a variable.

  • page() accessing as a function can be very convenient, when available.

  • wire('page') This works anywhere, and with any version of ProcessWire.

  • $this->page This is how you might access it from within a Wire-derived class.

  • $this->wire('page') A slightly more efficient way you can access from within a Wire-derived class.

  • $pages->wire('page') API variables can also access all other API variables, by way of their wire() method. In this example, we are accessing the $page API variable from the $pages API variable. So if you have any one API variable, then you actually have them all.

Accessing API variables as a function rather than a variable can be more convenient when the variable version may be out of scope, or if your IDE highlights API variables as undefined. So whenever we refer to an API variable, make note that access it however you'd like.

This is just an introduction to some of ProcessWire's API variables. Once you are familiar with these, you'll want to use ProcessWire's full API reference instead.

Some of ProcessWire’s most common API variables

  • $page

    The $page variable is provided to every template, and it contains all the fields specific to the page being viewed. This includes both built-in fields, which are common to all pages, as well as the custom fields.
  • $pages

    While the $page variable holds the current page, the $pages variable is where you can get at all the other pages in your site. It includes functions for getting, finding, saving and deleting pages.
  • $input

    The $input variable is your connection to GET, POST and COOKIE variables, URL segments, page (pagination) numbers, and more.
  • $sanitizer

    The $sanitizer functions are provided to fill the most common data sanitization needs with sites developed in ProcessWire. Always sanitize any data you get from user input.
  • $session

    This API variable provides access to read/write of session variables, login and logout of users, redirects, and more.
  • $fields

    $fields is an API variable that contains all the custom page fields in your site. It provides the API functions available in the admin control panel under Setup > Fields. Use it to retrieve, save or delete custom page fields.
  • $user

    The $user API variable is your connection to the current user viewing the page.
  • $log

    The $log API variable enables you to create, manage and filter log entries. Log files are stored in /site/assets/logs/.
  • $templates

    The $templates API variable provides access to all of your site’s templates. Use the $templates API variable to retrieve, modify, create or delete templates and control what fields are attached to them.
  • $config

    The $config API variable contains all the settings specific to your site configuration. This includes URLs and paths, database configuration, session configuration, and more.

Twitter updates

  • New ProcessWire query expansion search operators can now add automatic word inflections and lemmatisation, enabling you to build even smarter search engines with ProcessWire. More
    3 July 2020
  • ProcessWire 3.0.161 adds support for selector operator stacking, enabling you automatically broaden searches in a single pages.find() call— More
    26 June 2020
  • ProcessWire 3.0.160 adds powerful new text-searching operators, bringing a new level of power to page-finding API calls, especially when it comes to search engine type queries. Post also includes a demo search engine where you can test it all out live— More
    19 June 2020

Latest news

  • ProcessWire Weekly #320
    In the 320th issue of ProcessWire Weekly we're going to check out the latest core updates (ProcessWire 3.0.161), a new third party module called Fieldtype Runtime only, an IndieWeb themed article from Francesco Schwarz, and more. Read on!
    Weekly.pw / 27 June 2020
  • Powerful new text-searching abilities in 3.0.160
    In ProcessWire 3.0.160 we’ve got some major upgrades and additions to our text-search abilities. This brings a whole new level of power to $pages->find() and similar API calls, especially when it comes to search engine type queries.
    Blog / 19 June 2020
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“We were really happy to build our new portfolio website on ProcessWire! We wanted something that gave us plenty of control on the back-end, without any bloat on the front end - just a nice, easy to access API for all our content that left us free to design and build however we liked.” —Castus, web design agency in Sheffield, UK