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

  • ProcessWire 3.0.142 has a lot of updates but the biggest is the addition of custom fields support for file and image fields. In this post, we take a closer look at that, and also outline all of the new features in the just-released FormBuilder v40— More
    11 October 2019
  • This week’s dev branch version brings you improvements to ProcessWire’s input->cookie API variable, plus it adds the ability to modify system URLs and paths at runtime. This post also includes some examples to demonstrate just how useful this can be— More
    20 September 2019
  • New post: This week we’ll take a look at a new version of FormBuilder that's on the way (with a screencast), as well as the latest version of the core: ProcessWire 3.0.140— More
    6 September 2019

Latest news

  • ProcessWire Weekly #283
    The 283rd issue of ProcessWire Weekly introduces ProcessWire 3.0.142 and FormBuilder v40, highlights some conference content, and features a new weekly poll continuing with the #processwireworks theme. Read on!
    Weekly.pw / 12 October 2019
  • ProcessWire 3.0.142 core updates
    This latest version of the core on the dev branch has a lot of updates, bnd the biggest is the addition of custom fields support for file and image fields. In this post, we take a closer look and also outline all of the new features in the just-released FormBuilder v40.
    Blog / 11 October 2019
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