Symfony integration of squirrelphp/strings - make squirrel strings functionality easily available in Symfony

v0.11.1 2022-03-05 09:22 UTC

This package is auto-updated.

Last update: 2022-08-05 10:24:14 UTC


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Integration of squirrelphp/strings into Symfony through service tags and bundle configuration.


composer require squirrelphp/strings-bundle


Enable the bundle by adding Squirrel\StringsBundle\SquirrelStringsBundle to the list of your used bundles. The bundle then configures itself automatically.


String filters

The default ones are (links go to squirrelphp/strings documentation):

You can typehint Squirrel\Strings\StringFilterSelectInterface to get a service through which all filters are accessible by the getFilter method:

function (\Squirrel\Strings\StringFilterSelectInterface $selector) {
    $string = "hello\n\nthanks a lot!\nbye";

    $string = $selector->getFilter('ReplaceNewlinesWithSpaces')

    // Outputs "hello  thanks a lot! bye"
    echo $string;

You can also directly typehint a filter class, like Squirrel\Strings\Filter\NormalizeToAlphanumeric - all classes are registered as services in Symfony with their class names. All filter classes can also be instantiated in your application.

Form string filtering

This bundle automatically configures string filters for your form values that you can use via attributes, example:


use Squirrel\Strings\Annotation\StringFilter;

class NewsletterChangeAction
    public string $firstName = '';

    public string $confirmToken = '';

You can run one or more string filters and use any of the default list of filters or any of your own filters which you added. The filters are run as an early PRE_SUBMIT form event.

Beware: It only works if you map your class properties ($firstName and $lastName in this example) to the form without custom property paths, so the names used in the form have to be identical to the property names in the class. As long as you do not specify property_path in your form you are safe.

Adding new filters

Create a class, implement Squirrel\Strings\StringFilterInterface and tag the service with squirrel.strings.filter in a Symfony config file like this:

            - { name: squirrel.strings.filter, filter: MyCustomStringFilter }

The filter will be available in Squirrel\Strings\StringFilterSelectInterface under the name MyCustomStringFilter (the filter value you defined for the tag) as well as in the StringFilter attribute.

Random string generators

Generates random strings according to a list of possible characters. The following services are configured by default and can be injected into your services (they are implementing Squirrel\Strings\RandomStringGeneratorInterface):

  • squirrel.strings.random.62_characters generates a random string with the 62 alphanumeric characters (A-Z, a-z and 0-9)
  • squirrel.strings.random.36_characters generates a random string with the 36 alphanumeric lowercase characters (a-z and 0-9)
  • squirrel.strings.readfriendly_uppercase generates a random string with 27 easily distinguishable uppercase characters (234579ACDEFGHKMNPQRSTUVWXYZ), ideal if a human has to view and enter a code with such characters
  • squirrel.strings.readfriendly_lowercase generates a random string with 27 easily distinguishable lowercase characters (234579acdefghkmnpqrstuvwxyz), the same as the above uppercase variant, just in lowercase

You can add your own random string generator by creating a class implementing Squirrel\Strings\RandomStringGeneratorInterface and tagging it with quirrel.strings.random:

            - { name: squirrel.strings.random, generator: MyGenerator }

The generator name in camel case is used when getting a generator via the getGenerator method from the service Squirrel\Strings\RandomStringGeneratorSelectInterface (so 62Characters instead of 62_characters, and ReadfriendlyLowercase instead of readfriendly_lowercase), or if you want to inject the random string generator directly just convert the generator name to snake case, so in this example you could inject the service with @squirrel.strings.random.my_generator.

The classes Squirrel\Strings\Random\GeneratorAscii and Squirrel\Strings\Random\GeneratorUnicode are good base classes to use for your own needs, where you only need to define the allowed characters in the constructor:

        class: Squirrel\Strings\Random\GeneratorAscii
            - '6789'
            - { name: squirrel.strings.random, generator: MyGenerator }

        class: Squirrel\Strings\Random\GeneratorUnicode
            - 'öéèä'
            - { name: squirrel.strings.random, generator: MyUnicodeGenerator }

The first one would create a generator where only the characters 6, 7, 8 and 9 are generated, the second one where only the unicode characters ö, é, è and ä are generated. Just make sure to not use a character twice, otherwise the class will throw an exception.

String to number condensing