kkarpieszuk / wpml-fp-manual

wpml-fp-manual

Non official WPML Functional Programming Library manual

Repository url: https://git.onthegosystems.com/wpml-packages/fp

Installation

composer require wpml/fp

Use Fns::each() in place of foreach

Instead of writing:

$someArray = [ 1, 2, 3 ];
foreach ( $someArray as &$val ) {
  $val++;
} 

write:

$someArray = [ 1, 2, 3 ];

$someArray = Fns::each( function( $val ) {
  return $val++;
}, $someArray );

Use Obj::prop() instead of obtaining properties directly

Instead of:

$data = [
  'foo' => 'bar'
];

$data['foo'];

write:

$data = [
  'foo' => 'bar'
];

Obj::prop( 'foo', $data ); 

The advantage is, you don't need to know if $data is array or object. It will work with any data structure:

$data = new stdClass();
$data->foo = 'bar';

Obj::prop( 'foo', $data ); // the same as above

Use Obj::pathOr() to get default value or value from nested structure

If you have an array like this:

$data = [
  'foo' => [
    'bar' => 'baz'
  ]
];

and you want to obtain baz you can use:

$value = Obj::pathOr( 'not found', [ 'foo', 'bar' ], $data ); // returns 'baz'

if the element on path does not exist, the first argument will be returned:

$value = Obj::pathOr( 'not found', [ 'foo', 'bal' ], $data ); // returns 'not found'

Use Obj::keys instead of array_keys

Instead of:

$data = [
  'foo' => 'bar'
];
array_keys( $data );

write:

$data = [
  'foo' => 'bar'
];
Obj::keys( $data ); // returns [ 'foo' ]

You can obtain public object properties in the same way:

$data = new stdClass();
$data->foo = 'bar';

Obj::keys( $data ); // returns [ 'foo' ]

Use pipe() for ordered execution

You can chain functions to be executed from left to right with pipe().

Instead of writing:

$data = [
  'foo' => [
    'bar' => 'baz'
  ]
];

Fns::each( 'strtoupper', Fns::keys( Fns::prop( 'foo', $data ) ) );

write:

$data = [
  'foo' => [
    'bar' => 'baz'
  ]
];
$screamBar = pipe( Fns::prop( 'foo' ), Fns::keys()  );

Fns::each( 'strtoupper', $screamBar( $data ) );

Notice this time function in pipe does not take processed data as a second argument. Data comes from:

• first from function call with $data as argument ($screamBar( $data ))
• then data is passed from left to the right throught the pipe. So Fns::prop( 'foo' ) gets data from function call above, then it runs actions on it and what it returns, goes to the next function (Fns::keys() gets the result of Fns::prop( 'foo' ) which is [ 'bar' => 'baz' ])