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 3.0.148

Twitter updates

  • Weekly update for Jan 10, 2020—front-end file uploads in LoginRegisterPro with InputfieldFrontendFile module: More
    10 January 2020
  • If you haven't seen it yet, be sure to check out this great infographic by @teppokoivula in ProcessWire Weekly #294— How ProcessWire professionals work—the results of our recent weekly polls summarised: weekly.pw/issue/294/#how…
    3 January 2020
  • Today we have a new master version released, 3.0.148! There are 25 new versions worth of upgrades, fixes and optimizations in this new master version, relative to the previous. In this post we take a closer look at what’s new, how to upgrade, & more— More
    3 January 2020

Latest news

  • ProcessWire Weekly #298
    In the 298th issue of ProcessWire Weekly we're going to take a quick look at the latest core updates, introduce the PWGeeks project, and highlight some recently released ProcessWire content. Read on!
    Weekly.pw / 25 January 2020
  • ProcessWire 3.0.148 new master
    Today we have a new master version released, version 3.0.148! The last master version was 3.0.123, so there are 25 new versions worth of upgrades, fixes and optimizations in this new master version, relative to the previous. In this post we’ll take a closer look at what’s new, how to upgrade, and more.
    Blog / 3 January 2020
  • Subscribe to weekly ProcessWire news

I just love the easy and intuitive ProcessWire API. ProcessWire rocks!” —Jens Martsch, Web developer