[RFC] Optimize and extend the treeView in DC_Table

[agoat]

During development on an extended table driver for an extension to have a treeview that is sortable and has pagination (btw. both are technically possible, but in the end do not fit usablility, at least with pagination users lost orientation in the tree) i found some optimitation for the treeview.

The official demo page generates with a fully expanded treeview a significant amount of SQL Queries:

View	SQL count
Page tree	172
Article tree	415

With the optimized generateTree method the SQL Query count will drop down to:

View	SQL count
Page tree	136
Article tree	339

While debuging my SQL Queries I found a lot of the same query to the tl_page table called from the button callbacks in the tl_article dca. When using the PageModel instead of direct SQL, the count drops down to:

View	SQL count
Page tree	126
Article tree	134

So there is general dropp from 415 to 134 queries in total (nearly 60% unnecessary SQL queries). This may be important to pages with many articles (I had one which cause over 1200 SQL Queries opening the article tree)

I opened an extra PR (#1090) for the button callbacks problem!!

This PR handles only the logic of the generateTree method and add some features (arguable!!):

• Don't count the child records and when called recursively request the complete child records again
• Have an expand buttons (plus/minus) down to the last page (better overview with finer display options)
• Adds a feature to group by an attribute (e.g. in the article view group articles by 'inColumn')
• Adds a filter for the parent table (e.g. show only regular pages)
• Switched the order of child pages and articles (pages first - like folders and files)

Examples

Grouping

Grouping can be enabled by adding the group attribute to the dca with the following lines:

@@ dca/tl_article.php
// List
	'list' => array
	(
		'sorting' => array
		(
			'mode'                    => 6,
			'fields'                  => array('published DESC', 'title', 'author'),
			'paste_button_callback'   => array('tl_article', 'pasteArticle'),
			'panelLayout'             => 'filter;search',
			'group'			  => 'inColumn'
		),
		'label' => array
		(
			'fields'                  => array('title'),
			'label_callback'          => array('tl_article', 'addIcon')
		),

This will look like this:

Maybe there should be a better group icon.

Parent table filter

The parent table filter will be configured by the ptable attribute in the list sorting array:

@@ dca/tl_article.php
	// List
	'list' => array
	(
		'sorting' => array
		(
			'mode'                    => 6,
			'fields'                  => array('published DESC', 'title', 'author'),
			'paste_button_callback'   => array('tl_article', 'pasteArticle'),
			'panelLayout'             => 'filter;search',
			'group'			  => 'inColumn',
			'pfilter'		  => array('type=?', 'regular')
		),

And will result like this:

[leofeyer]

@contao/developers What about this PR?

[Toflar]

Guess it's gonna die if the work isn't picked up. @agoat, wanna give it another shot on our monorepo at https://github.com/contao/contao/ for maybe 4.10?

[agoat]

Ok, I will try making a new PR in the monorepo. But have to check this first on the latest contao version.

Last two years I was very busy with a big cloud project and all my extensions were hardly developed any further. First I guess I have to catch up with the latest contao version ;-) So many improvements during the last years..

[aschempp]

Honestly, I think it will be impossible to review the changes. Is there any use case for the feature in the Contao core?