---
name: "Petal::Hash::Test"
section: "3pm"
platform: "linux"
package: "libpetal-perl"
version: "2.26-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Petal::Hash::Test"
---

# Petal::Hash::Test(3pm)

Test and Tutorial Petal modifier

## NAME

Petal::Hash::Test - Test and Tutorial Petal modifier

## SUMMARY

Petal modifiers are snippets of code which are used to extend the expression engine capabilities. This test shows how to write your own modifiers.

## API

The modifier API is very, very simple. It consists of two elements:

### The package name

Your modifier should be called Petal::Hash::\<SomeThing\>, where \<SomeThing\> is the name that you want to give to your modifier.

For example, this modifier is called Petal::Hash::Test. Petal will automatically pick it the module up and assign it the 'test:' prefix.

```
    package Petal::Hash::Test;
    use warnings;
    use strict;
```

### The method $class-\>process ($hash, $argument);

This class method will define the modifier in itself.

\* `$class` is the package name of your modifier (which might come in handy if you're subclassing a modifier),

\* `$hash` is the execution context, i.e. the objects and data which will 'fill' your template,

\* `$argument` is whatever was after your modifier's prefix. For example, for the expression 'test:foo bar', `$argument` would be 'foo bar'.

In this test / tutorial we're going to write a modifier which uppercases a Petal expression.

```
  sub process
  {
      my $class    = shift;
      my $hash     = shift;
      my $argument = shift;
      return uc ($hash->get ($argument));
  }
  1;
  __END__
```

And that's it! Simple!

## AUTHOR

Jean-Michel Hiver

This module is redistributed under the same license as Perl itself.

## SEE ALSO

The template hash module:

```
  Petal::Hash
```