Symfony2 particular data transformer - forms

Question

I have an entity Calendar with dateFrom and dateTo properties.
Now in my form I have one hidden input with date formatted like this: 2010-01-01,2011-01-01.
How can I write a data transformer in Symfony2 which will allow me to transform this date to TWO properties?

Answer 1

I think that the transformer himself has nothing to do with the "properties", it just handle transformation from a data structure to another data structure. You just have to handle the new data structure on your code base.
The transformer himself might look like this :
class DateRangeArrayToDateRangeStringTransformer implements DataTransformerInterface
{
/**
* Transforms an array of \DateTime instances to a string of dates.
*
* #param array|null $dates
* #return string
*/
public function transform($dates)
{
if (null === $dates) {
return '';
}
$datesStr = $dates['from']->format('Y-m-d').','.$dates['to']->format('Y-m-d');
return $datesStr;
}
/**
* Transforms a string of dates to an array of \DateTime instances.
*
* #param string $datesStr
* #return array
*/
public function reverseTransform($datesStr)
{
$dates = array();
$datesStrParts = explode(',', $datesStr);
return array(
'from' => new \DateTime($datesStrParts[1]),
'to' => new \DateTime($datesStrParts[2])
);
}
}

Answer 2

You can use the explode function like that :
$dates = explode(",", "2010-01-01,2011-01-01");
echo $dates[0]; // 2010-01-01
echo $dates[1]; // 2011-01-01
Then create two new DateTime.

Answer 3

If it's possible, use 2 hidden fields. Then use a DateTime to String datatransformer on each field. Then your form is logically mapped to your entity.

Answer 4

I solved a similar problem by adding a custom getter/setter to my entity (for example, getDateIntervalString and setDateIntervalString). The getter converts dateTo and dateFrom into the interval string and returns it, and the setter accepts a similarly formatted string and uses it to set dateTo and dateFrom. Then, add the field to the form like this:
$builder->add('dates', 'text', ['property_path' => 'date_interval_string'])
By overriding the property path, your custom getter and setter will be used.