Can you fix the conflicts here and then we need some tests. Nice addon for extension developers!

@laoneo I have fixed the conflicts and updated the files to use namespaces where possible.

@Quy Thank you for the extra checking. All issues have been addressed.

I have tested this item ✅ successfully on 7e50ed8

Nice work and something I was looking for since the db fixer got added to the core. Thanks @roland-d for the fixes and @NunoLopes96 for your work on this.

I have tested this item ✅ successfully on 7e50ed8

RTC

Is it really necessary to use the session to store variables? From a quick glance the state of the model should be used for that or even defined variables in the model.
The model also compiles to much of HTML code. Would be nice to find a way to avoid that. Also get rid of the 700 extension (obviously I do miss here something).

The rest looks ok, and I would be happy to get that merged.

@laoneo

Is it really necessary to use the session to store variables?

I don't know :) My first priority was to bring the code in-sync with the 4.0-dev branch. I can see if we can do this different.

The model also compiles to much of HTML code. Would be nice to find a way to avoid that.

I am thinking we can do this with a layout.

Also get rid of the 700 extension (obviously I do miss here something).

Yes, as mentioned earlier this is the ID of the Joomla core. This is used throughout the core to identify the core files. Issue #20500 you mentioned, also seems to state we can keep this. For now I want to keep this ID until we have a solid solution for changing this.

@laoneo I have addressed all the issues you have raised. Can you have another look please?

Looks nice now, you could even get rid of the hardcoded 700 extension id and the session storage. Hope some of the testers like @Quy or @alikon test again, so that we can merge it.

Select all and click the Fix button.

An error has occurred.

    1064 You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ' '4.0.0-2018-03-05')' at line 3 

Call stack
# 	Function 	Location
1 	() 	JROOT\libraries\vendor\joomla\database\src\Mysqli\MysqliStatement.php:135
2 	Joomla\Database\Mysqli\MysqliStatement->__construct() 	JROOT\libraries\vendor\joomla\database\src\Mysqli\MysqliDriver.php:874
3 	Joomla\Database\Mysqli\MysqliDriver->prepareStatement() 	JROOT\libraries\vendor\joomla\database\src\DatabaseDriver.php:1755
4 	Joomla\Database\DatabaseDriver->setQuery() 	JROOT\administrator\components\com_installer\Model\DatabaseModel.php:457
5 	Joomla\Component\Installer\Administrator\Model\DatabaseModel->fixSchemaVersion() 	JROOT\administrator\components\com_installer\Model\DatabaseModel.php:258
6 	Joomla\Component\Installer\Administrator\Model\DatabaseModel->fix() 	JROOT\administrator\components\com_installer\Controller\DatabaseController.php:58
7 	Joomla\Component\Installer\Administrator\Controller\DatabaseController->fix() 	JROOT\libraries\src\MVC\Controller\BaseController.php:710
8 	Joomla\CMS\MVC\Controller\BaseController->execute() 	JROOT\libraries\src\Dispatcher\Dispatcher.php:161
9 	Joomla\CMS\Dispatcher\Dispatcher->dispatch() 	JROOT\libraries\src\Dispatcher\LegacyDispatcher.php:71
10 	Joomla\CMS\Dispatcher\LegacyDispatcher->dispatch() 	JROOT\libraries\src\Component\ComponentHelper.php:350
11 	Joomla\CMS\Component\ComponentHelper::renderComponent() 	JROOT\libraries\src\Application\AdministratorApplication.php:106
12 	Joomla\CMS\Application\AdministratorApplication->dispatch() 	JROOT\libraries\src\Application\AdministratorApplication.php:149
13 	Joomla\CMS\Application\AdministratorApplication->doExecute() 	JROOT\libraries\src\Application\CMSApplication.php:368
14 	Joomla\CMS\Application\CMSApplication->execute() 	JROOT\administrator\includes\app.php:38
15 	require_once() 	JROOT\administrator\index.php:36 

In PHP error log:

PHP Notice:  Undefined offset: 10000 in \administrator\components\com_installer\Model\DatabaseModel.php on line 254
PHP Notice:  Undefined index: extension in \administrator\components\com_installer\Model\DatabaseModel.php on line 258
PHP Notice:  Trying to get property 'extension_id' of non-object in \administrator\components\com_installer\Model\DatabaseModel.php on line 258

@laoneo @Quy Thanks for the review. I have fixed all except the one I don't understand :)

The PHP notices are gone as well as they related to the fatal error that was shown.

@alikon Thank you, query has been cleaned up.

When going to the list, it shows no results. You have to use the filters to see entries.

Remeber after any changes click "Find Problems" to refresh the cache

I don't see the Find Problems button.

@Quy All changes are done and the empty list has been fixed.

I don't see the Find Problems button.

In one of the earlier iterations of fixes this has been removed as it is no longer needed. I have removed it from the test instructions.

@Quy Do you know if there is anything better for this message:

This doesn't look very nice. Such a short sentence is already wrapped as well.

Even if you make it shorter in English to prevent it wrapping it may still wrap in other languages

@brianteeman I understand that, was more wondering if there is a new design/classes/functions to be used or if this is how it is at the moment in J4.

Ah. Iirc they are still being decided

I hope this alert boxes will get a restyle in the new template anyway, so we should not bother about being wrapped for now. As long as you do Factory::getApplication()->enqueueMessage, you should be fine.

What is the purpose of "select status" as there is no status displayed in the table

We need a no results found message when you have filtered and got no results. (For consistency)

Does it need to say "update version" - isn't it enough to simply say "version"

I found the word "update" a little confusing

@brianteeman I have removed the word Update and I added the No items found message. As for the Status filter, it was there when I took over this PR. I guess it comes from the Manage view. Now I wonder if this filter has any use. If we are going to keep it, I can add the Status column to this list, otherwise we can just remove this filter.

@Quy Thanks, all issues have been addressed.

Unless I miss something I can't see any reason to have the status column. Not even sure it makes sense even if you put it back. For example a component never has a status of anything other than enabled or disabled

Really looking forward to this being in core

The status filter has been removed.

@Quy I styled all columns the same way as the Extension -> Manage page. The title looks a little odd but not sure if this is OK. Please have a look and let me know if it needs any changing.

Looks good! ? One last change would be to replace Description with the title name in the popover. It is like that on Manage page (tooltip needs to be changed to popover).

Should it be Version in #__schemas?

@Quy Made the Description change.

Should it be Version in #__schemas?

I have named it Database Schema Version so you know which version is being talked about as this is specific.

Search in extension name. Prefix with ID: to search for an extension ID.

Searching on ID:700 results in Unknown column 'schemas.update_site_id' in 'where clause'

@Quy Not so crazy, that field doesn't exist :P I pushed the fixed for that.

@Quy You are merciless ? I will fix them tonight.

@Quy above issues fixed and some more changes for cleanup.

@Quy There must be 3 spaces after the param otherwise CS check fails.

For the Errors column, should the badges be Errors and not Problems?

In the screenshot, there is a horizontal line between the problem(s) and the stats, but this is not case.

@Quy I have aligned the wording. To me the word Problems is better than Errors because the issues don't have to error out the site. The site can function properly even though you have database problems.

Fix language string

I have tested this item ✅ successfully on 7e50ed8

THANK YOU!

I have tested this item ✅ successfully on 7e50ed8

Thank you guys very much for the hard work in the last days. Really appreciated!