What is Token:
Token is a small bits of text, which can be placed into a large documents as a simple placeholders
What Token Module Does?
The token module provides an API to provide tokens for other modules. It also provide some additional tokens and provide a browsing facility for all available tokens in UI.
How to create a custom token programatically?
In order to create a custom token, you will first need to create a custom drupal token module which will use the two important parts for this process,
A: Declaring the token (by using hook_token_info()).
hook_token_info():
It provides information of available placeholders and Token types
Return Value:
It returns an array of all available tokens and token type.
B: And providing values for the token (by using hook_tokens()).
hook_tokens(): It provides the replacement value of placeholder tokens.
Parameters:
$type: Machine name of type of token
$tokens: Array of tokens
$data: Array of data objects
$options: Array of options for token replacement
\Drupal\Core\Render\BubbleableMetadata
$bubbleable_metadata: Bubbleable metadata
Return Value:
It return an associative array of replacement values.
Other Token hooks:
1. hook_token_info_alter():
Parameter:
$data - Array of tokens.
2. hook_tokens_alter()
Parameter:
$replacements - Array of replacements return by hook_tokens().
$context - Array of all keys of hook_tokens().
To create a custom module, first go to your drupal site's module directory and create a new folder there with your custom module name. In this Folder, create a new file with your module's name. Example custom_token.info.yml. In this file implements the following code.
Create Token File :
So, create a file inside your custom module directory and give it the same name as your custom module but with the extension .module. In my case, it will be custom_token.module. In this file, implement the following code:
<?php
/**
* @file
* contains custom_token.module..
*/
use Drupal\Core\Render\BubbleableMetadata;
/*
* Implemets : hook_token_info().
*/
function custom_token_token_info() {
$types['custom_token_type'] = array(
'name' => t('Custom Token Type'),
'description' => t('Define Custom Token Type')
);
$tokens['custom_token_name'] =array(
'name' => t('Custom Token Name'),
'description' => t('Define Custom Token Name')
);
return array(
'types' => $types,
'tokens' => array(
'custom_token_type' => $tokens
)
);
}
/*
* Implements hook_tokens()
*/
function custom_token_tokens($type, $tokens, array $data, array $options, \Drupal\Core\Render\BubbleableMetadata $bubbleable_metadata) {
$replacements = [];
if ($type == 'custom_token_type') {
foreach ($tokens as $name => $original) {
switch ($name) {
case 'custom_token_name':
$text = 'My Custom Token';
$replacements[$original] = $text;
break;
}
}
}
return $replacements;
}
The first part of the code that uses the hook_token_info() function is used to declare the tokens as well as what function it should perform and make them visible to Drupal.
In the second half of the code, the hook_tokens() function is used to actually make the token perform its desired function.
