Token Replace

This simple package allows you to define tokens that can be replaced in strings. Instead of a simple str_replace, Token Replace lets you add options to each token. Let's start with an example.

$input="Today is { date:m }}/{{ date:d }}/{{ date:y }}.";  
  
echo \HollyIT\TokenReplace\TokenReplacer::from($input)  
    ->with('date',  \HollyIT\TokenReplace\Transformers\DateTransformer::class)  
      
// Results in: Today is 11/11/21.      
  

There is a certain anatomy to tokens, so let's take a look
at the {{ date:m }}. This is a default token format, but
this format is configurable globally and per instance.

Part	Name	Global Setting	Local Setting
{{	Token Start	$defaultStartToken	$instance->startToken()
date	Token Name	---	---
:	Token Separator	$defaultTokenSeparator	$instance->tokenSeparator()
m	Options	---	---
}}	Token End	$defaultEndToken	$instance->endToken()

Transformers

The replacement of tokens is handled via a transformer. A transformer can be a closure or a simple class.

Transformers can be added to each instance of the TokenReplacer or added globally by executing the following in the bootstrap phase of your app:

\HollyIT\TokenReplace\TokenReplacer::$defaultTransformers = [  
  'date' => \HollyIT\TokenReplace\Transformers\DateTransformer::class  
];

Per instance tokens are added via $instance->with({token name}, {class name, transformer instance or closure}); For closure based transformers the signature is:

function(string $options, TokenReplacer $replacer)

Included Transformers

All these transformers live under the \HollyIT\TokenReplace\Transformers namespace.

Transformer	Description	Instantiating
ArrayTransformer	Extracts a value from an array based on a key.	The array
DateTransfomer	Extract parts of a date by PHP date format tokens.	Date object, Carbon, date string or null (assumes now())
FileTransformer	Extract parts from a file based on pathinfo().	The path string
ObjectTransformer	Extract a property from an object.	The object
UrlTransformer	Extract based on parse_url()	The URL string

There are also special Laravel transformers residing in \HollyIT\TokenReplace\Transformers\Laravel

Transformer	Description	Instantiating
AuthTransformer	Extract a property from the auth (user) object	none
DotArrayTransformer	Extract a property using Laravel's dot syntax	the array
ModelTransformer	Extract a property from an Eloquent model. For date properties, you can add the date part by specifying the format after the property name (ie: model:created_at,m)	The model
UploadFileTransformer	Extract the basename or extension from an UploadedFile object	The upload

Post processing.

None of the transformers do any further processing except extracting the item. If you want to do further processing, such as escaping the replacements, you can define an onReplace callback:

$replacer->onReplace(function(string $result, string $token, string $options){  
  return strtoupper($result);  
});

This callback will run for every token occurrence found, so you can further filter down what tokens to operate on by checking the $token property.

Invalid or missing tokens

By default invalid and missing tokens will remain in the string. To prevent this, you can set removeEmpty() on the TokenReplacer.

Future Plans

This project was born out of a repeated scenario I faced on numerous projects. There are no real future plans for it. The entire objective here is a very simple solution to a common problem. You may find a transformer or feature that should be included. If so, please submit a PR. I'm very open on extending the project to cover more use cases.