Fieldtype::exportValue() method

Given a value, return an portable version of it as either a string, int, float or array

If an array is returned, it should only contain: strings, ints, floats or more arrays of those types. This is intended for web service exports.

When applicable, this method should map things like internal IDs to named equivalents (name, path, etc.).

If not overridden, this takes on the same behavior as Fieldtype::sleepValue(). However, if overridden, it is intended to be more verbose than wakeupValue, where applicable.

Usage

// basic usage
$string = $fieldtype->exportValue(Page $page, Field $field, $value);

// usage with all arguments
$string = $fieldtype->exportValue(Page $page, Field $field, $value, array $options = []);

Arguments

NameType(s)Description
pagePage
fieldField
valuestring, int, float, array, object, null
options (optional)array

Optional settings to shape the exported value, if needed:

  • system (boolean): Indicates value is being used for a system export via $pages->export() call (default=false).
  • human (boolean): When true, Fieldtype may optionally emphasize human readability over importability (default=false).

Return value

string float int array


Hooking Fieldtype::exportValue(…)

You can add your own hook events that are executed either before or after the Fieldtype::exportValue(…) method is executed. Examples of both are included below. A good place for hook code such as this is in your /site/ready.php file.

Hooking before

The 'before' hooks are called immediately before each Fieldtype::exportValue(…) method call is executed. This type of hook is especially useful for modifying arguments before they are sent to the method.

$this->addHookBefore('Fieldtype::exportValue', function(HookEvent $event) {
  // Get the object the event occurred on, if needed
  $Fieldtype = $event->object;

  // Get values of arguments sent to hook (and optionally modify them)
  $page = $event->arguments(0);
  $field = $event->arguments(1);
  $value = $event->arguments(2);
  $options = $event->arguments(3);

  /* Your code here, perhaps modifying arguments */

  // Populate back arguments (if you have modified them)
  $event->arguments(0, $page);
  $event->arguments(1, $field);
  $event->arguments(2, $value);
  $event->arguments(3, $options);
});

Hooking after

The 'after' hooks are called immediately after each Fieldtype::exportValue(…) method call is executed. This type of hook is especially useful for modifying the value that was returned by the method call.

$this->addHookAfter('Fieldtype::exportValue', function(HookEvent $event) {
  // Get the object the event occurred on, if needed
  $Fieldtype = $event->object;

  // An 'after' hook can retrieve and/or modify the return value
  $return = $event->return;

  // Get values of arguments sent to hook (if needed)
  $page = $event->arguments(0);
  $field = $event->arguments(1);
  $value = $event->arguments(2);
  $options = $event->arguments(3);

  /* Your code here, perhaps modifying the return value */

  // Populate back return value, if you have modified it
  $event->return = $return;
});

Fieldtype methods and properties

API reference based on ProcessWire core version 3.0.168

Twitter updates

  • ProcessWire 3.0.171 dev branch core updates – More
    22 January 2021
  • Preliminary 2021 roadmap in progress in this week’s update— More
    8 January 2021
  • Happy New Year! Today I’ve bumped the version on the dev branch to 3.0.170, and it’s quite a lot of updates. This post covers most of them. In this post, there’s also a question for you: what would you like to see in ProcessWire in 2021? More
    1 January 2021

Latest news

  • ProcessWire Weekly #350
    In the 350th issue of ProcessWire Weekly we'll check out ProcessWire 3.0.171, highlight some recent forum threads and other ProcessWire resources, and introduce a brand new site of the week. Read on!
    Weekly.pw / 23 January 2021
  • ProcessWire 3.0.170 core updates
    Happy New Year! Today I’ve bumped the version on the dev branch to 3.0.170, and it’s quite a lot of updates. This post covers most of them. In this post, there’s also a question for you: what would you like to see in ProcessWire in 2021?
    Blog / 1 January 2021
  • Subscribe to weekly ProcessWire news

“I am currently managing a ProcessWire site with 2 million+ pages. It’s admirably fast, and much, much faster than any other CMS we tested.” —Nickie, Web developer