Unable to transform RRule to text when it has a WEEKLY frequency and no BYDAY

[markpruett571]

Hi there!

If you try to parse a rrule with frequency set to WEEKLY and no BYDAY set, it'll give you an error:

PHP Error: Call to a member function format() on null in .../vendor/simshaun/recurr/src/Recurr/Transformer/TextTransformer.php on line 282

Sample code to reproduce the error:
echo (new \Recurr\Transformer\TextTransformer)->transform(new Recurr\Rule('FREQ=WEEKLY'));

This is on version 4.0.2

[jglhelias]

You're right. I faced the same situation.

As you wrote it's easy to reproduce.

$rrule = new \Recurr\Rule('FREQ=WEEKLY');
$transformer = new \Recurr\Transformer\TextTransformer();
echo $transformer->transform($rrule);

The above example will output:
Fatal error: Uncaught Error: Call to a member function format() on null in vendor\simshaun\recurr\src\Recurr\Transformer\TextTransformer.php on line 282

Except that, according to the RFC 5545 Section 3.8.2.4, you can read:

This property is REQUIRED in all types of recurring calendar components that specify the "RRULE" property.

So you must explicitelly define a start date in the constructor.

$rrule = new \Recurr\Rule('FREQ=WEEKLY', new \DateTime());
$transformer = new \Recurr\Transformer\TextTransformer();
echo $transformer->transform($rrule);

The above example will output:
weekly on Thursday

Maybe the library should warn the user that the instance lacks of a start date while a rrule is set, avoiding the transformer to throw an exception.