add support for LazyCollections

[vitorccs]

Hi @Xint0-elab

I would like to bring a point for discussion:

I have just noticed the FromQueryCursor implementation is not necessary because Laravel cursor returns a LazyCollection.

So rather than creating a new interface, we can use FromCollection - see below:

I have created unit tests for both use cases above, and they passed perfectly.

PS: I appreciated very much the refactor you did in FromCollection and Writer because they both enabled this library to work with LazyCollections.

Do you agree with this PR?

[Xint0-elab]

Looks fine, I added the FromQueryCursor just to make it simpler to migrate existing exports that use FromQuery to just implement the new interface without any other changes.

So that if you already have an export:

class MyQueryExport implements FromQuery
{
    public function query()
    {
        return Model::query()->{...complex query...};
    }
}

You only need to change FromQuery to FromQueryCursor to get the LazyCollection funcionality without any other changes:

class MyQueryExport implements FromQueryCursor
{
    public function query()
    {
        return Model::query()->{...complex query...};
    }
}

[Xint0-elab]

Also, with the FromQueryCursor interface counting the records executes a count query; with the FromCollection implementation, I believe the code will traverse the whole collection twice, once for counting and the second time for generating the export.

[vitorccs]

Also, with the FromQueryCursor interface counting the records executes a count query; with the FromCollection implementation, I believe the code will traverse the whole collection twice, once for counting and the second time for generating the export.

Good point. FromQuery runs a count query to be able to chunk (paginate):

https://github.com/vitorccs/laravel-csv/blob/73c77528fb19e3b778fe18d925b9141d1503c9e1/src/Services/Writer.php#L69

However, FromCollection outputs all contents directly without counting: https://github.com/vitorccs/laravel-csv/blob/73c77528fb19e3b778fe18d925b9141d1503c9e1/src/Services/Writer.php#L60

Also, the query is run only once, at the moment it will iterate the records:

[Xint0-elab]

Hi @vitorccs, when will you tag a new release?

[vitorccs]

@Xint0-elab done

[Xint0-elab]

Thank you @vitorccs

On Wed, Apr 12, 2023 at 10:18 AM Vitor Siqueira @.***> wrote:

@Xint0-elab https://github.com/Xint0-elab done

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