FIX Ensure correct link is used when gridfield is readonly

[AljosaB]

Requires silverstripe/silverstripe-framework#11228

Issue

• Wrong link without edit premissions #89

[robbieaverill]

Thanks for taking the time to create a pull request for this issue! I haven't had time yet to test the code out, but thought I'd mention that I'm not super happy about the approach.

I don't think that overloading the GridField class is necessary to fix your issue - I also think you should be able to use GridFieldConfig to target and replace the View button with what appears to be a sort of Edit button. If you can do this (I haven't looked far enough into it yet) then you can get away with less changes and less new APIs introduced.

I'll pick this up later this week and have a closer look. In the meantime, please let me know what you think =)

[NightJar]

I agree with @robbieaverill - only a single class needs to be introduced (the new GridFieldSiteTreeViewButton you've created @AljosaB), and edits to the components for the GridField would be more appropriate in GridFieldConfig_Lumberjack :)

[AljosaB]

The thing is, there is no View button in GridField config, so I can not replace it. There is Edit button that gets replaced later when canEdit check is made

LeftAndMain::getEditForm (Edit button is removed somewhere after this)

if (!$record->canEdit()) {
	$readonlyFields = $form->Fields()->makeReadonly();
	$form->setFields($readonlyFields);
}

and in the end View button is added in GridField::performReadonlyTransformation

// As the edit button may have been removed, add a view button if it doesn't have one
if (!$copyConfig->getComponentByType(GridFieldViewButton::class)) {
	$copyConfig->addComponent(new GridFieldViewButton);

I didn't find any hook after that to replace View button with my extended View button, that's why I had to introduce an extended GridField and overload performReadonlyTransformation function. I hope you find a better solution.

[robbieaverill]

I'll take a look at this later this week :)

[GuySartorelli]

I've updated this PR to use the newish API for updating the set of readonly components.
It requires a companion PR in framework so the correct view button class is used.

[emteknetnz]

Tested locally, works well