Added implode method

[maxalmonte14]

This implementation is directly taken from #8 issue.

Now all CollectionAbstract children have an implode method available.

A call in a ColumnCollection should be as the following:

$columnCollection->implode(',', function ($column) {
    return $column->getLabel();
});

And, in a RowCollection:

$rowCollection->implode("\n", function ($row) {
    return implode(',', $row);
});

Tests are included, but like we don't test abstract classes I made it with the CollumnCollection class.

[maxalmonte14]

Interesting, this PR doesn't pass the CI, I have the following output in my development environment, even before implementing the feature, so I don't see what's is missing.

 ------------------------------------------------------------------------------------------------------------------------------------
  Error
 ------------------------------------------------------------------------------------------------------------------------------------
  Ignored error pattern #Result of method [a-zA-Z]+::[a-zA-Z]+\(\) \(void\) is used.# was not matched in reported errors.
  Ignored error pattern #Method [a-zA-Z\\]+::[a-zA-Z]+\(\) should return bool but returns void.# was not matched in reported errors.
 ------------------------------------------------------------------------------------------------------------------------------------

[maxalmonte14]

I'm a newbie in this PHPStan thing but if I remove the whole parameters key in the phpstan.neon file I have no errors 😅

[maxalmonte14]

I also think RowCollection class should store Row objects instead of simple arrays, this way we could implement the __toString magic method and return all the properties separated by ,, like so:

Row class:

class Row
{
    public function __toString()
    {
        return implode(',', $this->items);
    }
}

And then call

$rowCollection->implode("\n", function ($row) {
    // return implode(',', $row);
    return $row;
});

[willishq]

I just took the ignore errors thing out because it was complaining that the errors I told it to ignore were not found when running phpstan.

[maxalmonte14]

That was my first thought, well, now we can focus on the exporters repo 👍