composer require flow-php/etl ~0.28.0 
Read from various data sources.
Shape and optimize for your needs.
Store and secure in one of many available data sinks.
Basic usage of the when transformation function.
The when function provides conditional logic within data transformations. It evaluates a condition and returns different values based on whether the condition is true or false.
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when(
condition: BooleanExpression,
then: mixed,
else: mixed
): mixed
In this example, we use when to add a new entry is_special that checks if a row is both active AND contains the 'foo' tag.
composer.json
{
"name": "flow-php/examples",
"description": "Flow PHP - Examples",
"license": "MIT",
"type": "library",
"require": {
"flow-php/etl": "1.x-dev"
},
"minimum-stability": "dev"
}code.php<?php
declare(strict_types=1);
use function Flow\ETL\DSL\{data_frame, from_array, lit, ref, to_stream, when};
require __DIR__ . '/vendor/autoload.php';
data_frame()
->read(from_array([
['id' => 1, 'email' => 'user01@flow-php.com', 'active' => true, 'tags' => ['foo', 'bar']],
['id' => 2, 'email' => 'user02@flow-php.com', 'active' => false, 'tags' => ['biz', 'bar']],
['id' => 3, 'email' => 'user03@flow-php.com', 'active' => true, 'tags' => ['bar', 'baz']],
]))
->collect()
->withEntry(
'is_special',
when(
ref('active')->isTrue()->and(ref('tags')->contains('foo')),
lit(true),
lit(false)
)
)
->write(to_stream(__DIR__ . '/output.txt', truncate: false))
->run();
+----+---------------------+--------+---------------+------------+
| id | email | active | tags | is_special |
+----+---------------------+--------+---------------+------------+
| 1 | user01@flow-php.com | true | ["foo","bar"] | true |
| 2 | user02@flow-php.com | false | ["biz","bar"] | false |
| 3 | user03@flow-php.com | true | ["bar","baz"] | false |
+----+---------------------+--------+---------------+------------+
3 rows
