Add withFiles() functionality to CRUD fields

[pxpm]

WHY

BEFORE - What was wrong? What was happening before this PR?

Managing uploads with backpack fields could be a challenge sometimes. Especially if we are talking about repeatable fields etc.

This PR aims to provide a tool to help developers setup their file uploads quicker ... well .. way way quicker 😄

AFTER - What is happening after this PR?

You should be able to get a fully working upload field in your crud with just:

CRUD::field('document')->type('upload')->withFiles();
CRUD::field('documentsss')->type('upload_multiple')->withFiles();
CRUD::field('passport_image')->type('image')->withFiles();

Is it a breaking change?

No it's not! Fantastic!

How can we test the before & after?

Will write some docs later.

[scrutinizer-notifier]

The inspection completed: 36 new issues, 77 updated code elements

[tabacitu]

This is much MUCH better Pedro! Only a few questions really, nothing important. This is GOOD TO GO! 🎉🎉🎉

[tabacitu]

Hmmm could/should we make this for() to match the other one? And maybe it reads better? FileNameGenerator::for('somefile.txt') - what do you think @pxpm?

[pxpm]

I agree with this, let's dor it 💪

[pxpm]

image

Requires manual validation (no laravel rules supplied to handle base64). One can use a package like https://github.com/crazybooot/base64-validation

• When nothing changes, the field send the db path in the request.
• When file is deleted and a new one is NOT added, it will send an empty value (null) in request.

Even using the package mentioned it cannot be used with regular laravel validation (eg. form requests), requiring custom validation to properly work.
Possible solution: don't send nothing when nothing changes. allowing devs to supply two validators (create/update with required/sometimes respectively), see upload example bellow.

upload

Need two separate validators, one for create and another for update.

• When file is deleted and a new one is NOT added, it will send an empty value (null) in request.

use case: required avatar field (can never be null needs to be a valid file)

// create validation:
'avatar' => [
                'required', // on create this field must be a valid type
                File::types(['pdf'])
                    ->min(1024)
                    ->max(10 * 1024),
            ],
// update validation:
'avatar' => [
                'sometimes', // if nothing change, nothing is validated. If file is cleared an empty value is sent and it will trigger the validation error.
                File::types(['pdf'])
                    ->min(1024)
                    ->max(10 * 1024),
            ],

upload_multiple

Requires custom validator to properly validate. No other way around, needs breaking change to fix.

There is one hidden input that when nothing changes on field breaks the sending values and sends [ [0=>null] ].

Assuming now we make it like upload so that when nothing changes the validation is not run.

When you delete a file it gets added to a clear_field hidden input used to clear the files. There is a major problem if we do it that way: if you clear ALL files, and your field is required, the validation wouldn't run and the same values would be kept on the db assuming nothing changed in the field.

We can do the same we do in upload, so when ALL files are cleared an hidden input is added with an empty value, making the validation work again.

This goes against #3278 that proposed we send the value instead. I don't think we should be sending the input, what are we validating in a string ? It indeed stores a string, but as far as "application validation" is concerned, what comes from the form should be a file, with type x, size y etc, otherwise don't touch that input.

[tabacitu]

Code review ✅ I'm ok with merging this as-is. My only (small) mention is that we might reconsinder some parameter names for temporary URLs - what I said in https://github.com/Laravel-Backpack/docs/pull/421/files

[tabacitu]

GOD FUCKING DAMN, THIS WOKS WELL! It works like freakin' magic! Well done Pedro 👏👏👏 Well freakin' done!