Create an administration UI for managing Navigation Blocks

I'll prototype this over the next few days.

I got to a good stopping point, so I thought I would post the MR. It's not done yet, but many of the back end pieces are put in place here, including (not exhaustive):

• New navigation_section config entity and supporting handlers
• Aligned NavigationSection plugins to be more block-like, includeing NavigationSection attribute
• Renamed plugin folder from Navigation to NavigationSetion to follow convention
• Define config schema for navigation_section as well as existing navigation_section settings
• Install 4 navigation_section config entities that we currently have
• Use navigation_section config entities to render the navigation toolbar
• Block-like navigation_section theme hook, preprocess and template

Still to do:

• navigation_section list_builder handler evaluation. Might not need this, came with drush generate
• Flesh out the admin UI on top of all the data layer implementation. Keep an eye toward allowing a future for multi-region management, but we only need content region management for now
• Make sure contextual region / menu stuff works as expected
• Much testing

Will keep working on these tomorrow.

Thanks for testing @Prashant.c.

As I noted in my previous comments, I'm still actively working on the issue. The default list builder came along with the drush generate command when I initially ran it to get a start on the config entity. We won't be using it, as we're going to create a UI like blocks (with "Place Navigation Section" buttons, dialogs, etc.).

I'll note clearly in comments when I'm done with the initial work and at that time will unassign and invite further commits. It's good to avoid duplicate effort. Thanks!

More commits!

I've fleshed out most of the back-end pieces for the Navigation section layout admin UI. You can now:

• Visit /admin/structure/navigation-section and see a listing of existing navigation_section config entities. NOTE: we talked about limiting this to only the content region. It presently works with both regions, just to keep that possibility open. We can restrict that in future.
• Reorder navigation sections, even move into differnt regions. NOTE: presently the Javascript is not active, so you have to use the region select form element to change to a different region.
• Place navigation section brings up a dlalog with a library of navigation section plugins to choose from
• You can create a new navigation section config entity by clicking "Place navigation section" in the library dialog. You get the navigation section plugin form, and warpping navigation section entity form, just like blocks
• Delete a navigation section config entity

Several caveats at this point:

• Any functionality depending on Javascript, I haven't gone through yet. Filter mechanism on the navigation section libary dialog is one example.
• Visibility settings don't get used yet
• Rendering multiple of the same can produce weird results, there may be additional themeing considerations to accomodate the added flexibility here.
• Not sure if exposing the 'Category' in the UI is useful? Probably worth it, who knows how this would get implemented, maybe many plugins would proliferate in contrib.

I'm continuing to work through open issues.

I'm at a good stopping point now. I'm going to unassign and set to Needs review.

From #6, I've finished:

• navigation_section list_builder handler evaluation. Might not need this, came with drush generate
• Flesh out the admin UI on top of all the data layer implementation. Keep an eye toward allowing a future for multi-region management, but we only need content region management for now. I decided to keep content and footer region management. Good for testing, also, seems feasible that some users may prefer their shortcuts in the footer, which totally works.
• Make sure contextual region / menu stuff works as expected
• Much testing. More needed!

From #10, I've finished:

• Any functionality depending on Javascript, I haven't gone through yet. Filter mechanism on the navigation section libary dialog is one example.
• Visibility settings don't get used yet
• Not sure if exposing the 'Category' in the UI is useful? Probably worth it, who knows how this would get implemented, maybe many plugins would proliferate in contrib.

Additional notes.

From #10:

Rendering multiple of the same can produce weird results, there may be additional themeing considerations to accomodate the added flexibility here.

This is still true, but would be an issue for a followup ticket. It works now to do this. We can talk about theming considerations / restrictions in a followup.

From #10:

Not sure if exposing the 'Category' in the UI is useful? Probably worth it, who knows how this would get implemented, maybe many plugins would proliferate in contrib.

I thought about this. Category will probably be useful. By default it comes from the module providing the NavigationSection plugin, hence they are all showing as "Navigation". I can imagine a future when this gets into core where the User NavigationSection goes into the user module, the Shortcuts NavigationSection goes into the shortcut module, etc. Plus contrib and it will be useful to have and display. I left it in.

Also, a note about contextual links. I fixed them in a recent commit, so that, like blocks you can use it to get to the edit form or remove a navigation section placement. The front end UX is very awkward though. There will be front-end work to do here to get it all sorted. Would be a good follow up. Maybe we hide it in this MR, with the intent to unhide and fix the UX in a follow up.

Any feedback on functionality or code review is very much welcome.

1. i don't really think that contextual links should be added. This is mostly admin menu. It is kind of annoying action for 99% of users who don't want to use anything except default navigation blocs layout.

I tend to agree with you. When @ckrina and I originally discussed this, we said lets include contextual links, but yeah... now that I see it, it's problematic. Let's see what @ckrina thinks when she has a minute to review. I'm leaning towards excluding contextual links, or at least hiding it here for now and addressing the UX in a follow up in order to be able to include them.

2. I don't want jQuery appear in new core code. https://www.drupal.org/project/drupal/issues/3052002. I would better rewrite it with vanilla js.

Yep! This Javascript was copy pasted from core's block code hence why jQuery came along for the ride. We can for sure rewrite to avoid jQuery.

3. Probably we need to have button "Reset to default" in navigation layout settings? I guess can be much more blocks in future. Unexperienced users easy can break all site controls.

Perhaps? Although I'd arguee for most users, they wouldn't venture into the admin UI to adjust anything here, especially if we remove contextual links. Not sure it's worth the effort.

2. Despite updating the section title in the backend, the displayed title remains unchanged.

Nice catch @Prashant.c. I've fixed that in the last commit.

3. There is an issue with the scrolling functionality when the "Administration" section is positioned in the footer. The navigation bar does not scroll due to an overlap problem, and no scrollbar appears. Please see the image below for a visual representation.

Yeah, there will be dragons when placing things outside their intended place. This is a front-end issue and outside the scope here. We can talk about restrictions we may or may not want to place here. Adjusting styles to cope with more flexible placement would be out of scope here and a good candidate for a follow up.

Updated issue summary with more remaining tasks based on discussion.

Great feedback. I will work on these items this morning.

We met this morning to discuss the remaining items here. In summary:

We will create follow up issues for the following:

• I've hidden the contextual links in c75d1839. In a follow up, we will work on a single contextual link for the whole Navigation to link to the Navigation section UI. Follow up: #3412116: Add contextual link for the whole Navigation bar to link to the Navigation Admin UI.
• Restrict configuration of the toolbar footer items. Users should only be allowed too manage the content region of the navigation through the UI. Follow up: #3412119: Restrict configuration of the Navigation bar footer items.
• The help link, which has already been taken out of main nav, and is in footer of Navigation now, will be made its own item to be able to reorder it. Follow up: #3412128: Decouple 'Help' link from the footer region, allow to be configured via Navigation admin UI.
• Revert to default in navigation layout settings from the UI. Follow up: #3412123: Revert to default in navigation layout settings from the UI.
• Refactor jQuery to vanilla Javascript. Follow up: #3412125: Convert jQuery to vanilla Javascript.

Work to do in this issue

• Move the ‘navigation sections’ link from the Structure parent link to the Configuration parent link. Done in 9c93a9f7.
• Rename ‘navigation sections’. Consensus amongst those in the meeting was 'Navigation components'. @ckrina to solicit some buy in on this, as the change is tedious to make. It's a machine name that gets used in the code a lot.

Made changes to issue title and description to reflect new "Navigation Block" language.

I've made the change to rename "Navigation Section" to "Navigation Block" in the code. Ready for review.

Thanks @plopesc! I'll get to work on those straight away.

Fixes made! Please review.

Also see my comment in the one open thread. Let me know if your OK with that.

Thanks @plopesc!

Thanks @plopesc!

I think with both @plopesc and @Prashant.c's reviews and all threads resolved, this is good to go.

Marking as RTBC.