Wire::addHookBefore() method

Add a hook to be executed before the hooked method

  • Use a "before" hook when you have code that should execute before a hookable method executes.
  • One benefit of using a "before" hook is that you can have it modify the arguments that are sent to the hookable method.
  • This type of hook can also completely replace a hookable method if hook populates an $event->replace property. See the HookEvent class for details.

Example

// Attach hook to a method in current object
$this->addHookBefore('Page::path', $this, 'yourHookMethodName');

// Attach hook to an inline function
$this->addHookBefore('Page::path', function($event) { ... });

// Attach hook to a procedural function
$this->addHookBefore('Page::path', 'your_function_name');

// Attach hook from single object instance ($page) to inline function
$page->addHookBefore('path', function($event) { ... }); 

Usage

// basic usage
$string = $wire->addHookBefore($method, $toObject);

// usage with all arguments
$string = $wire->addHookBefore($method, $toObject, $toMethod = null, array $options = []);

Arguments

NameType(s)Description
methodstring, array

Method to hook in one of the following formats (please omit 3 leading underscores):

  • Class::method - If hooking to all object instances of the class.
  • method - If hooking to a single object instance.
  • Since 3.0.137 it may also be multiple methods to hook in CSV string or array.
toObjectobject, null, callable

Specify one of the following:

  • Object instance to call $toMethod from (like $this).
  • Inline function (closure) if providing implemention inline.
  • Procedural function name, if hook is implemented by a procedural function.
  • Null if you want to use the 3rd argument and don't need this argument.
toMethod (optional)string, array

Method from $toObject, or function name to call on a hook event. This argument can be sustituted as the 2nd argument when the 2nd argument isn’t needed, or it can be the $options argument.

options (optional)array

Array of options that can modify behavior:

  • type (string): May be either 'method' or 'property'. If property, then it will respond to $obj->property rather than $obj->method(). The default type is 'method'.
  • priority (int): A number determining the priority of a hook, where lower numbers are executed before higher numbers. The default priority is 100.

Return value

string

A special Hook ID (or CSV string of hook IDs) that should be retained if you need to remove the hook later.


Wire methods and properties

API reference based on ProcessWire core version 3.0.137

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 #284
    In the 284th issue of ProcessWire Weekly we're going to take a quick look at the latest core updates, introduce a new module called InputfieldFloatRange, and continue our ongoing poll series #processwireworks. Read on!
    Weekly.pw / 20 October 2019
  • ProcessWire 3.0.142 core updates
    This latest version of the core on the dev branch has a lot of updates, and 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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