Allow filtering by tag in the frontend

[danielsmink]

Resolves filtering by tags in the frontend. resolve #5998

How to test

1. Create a fresh Joomla
2. Create some articles with tags
3. Create a new menu item -> articles -> category list
4. Select 'Tag' as filter field
5. Browse to the menu item in the frontend.
6. Filter on any of the tags using the dropdown

[justinherrin]

Can you also add "Tags" option to the Global Configuration area? I'm looking at the Global Configuration > Articles > List Layouts tab > Filter Field

[danielsmink]

@justinherrin added to Global config as well. Thanks for the heads up! Found a little bug while doing that.

[ghost]

I have tested this item 🔴 unsuccessfully on c26ed28

1. Label looks strange

1. If no tag selected changing filter field Display # results in a message "no items".
   
2. Same behavior if you had selected a tag, got hits, and set back field to "Select Tag"

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Addition

This is what I did:

Installed Joomla! 3.5.0-beta staging 2016-01-17 with demo datas (testing).
Applied patch.
Opened menu item All Front End Views > Article Category List
Changed category to: Sample-Data Articels.
Tabulator Category > Subcategory Levels: ALL
Tabulator List Layout > Filter Fields > Tags
Saved.

Added tags to several articles by batch button

Went to Content > Articles > Options button
Tabulator Blog/Featured Layouts > Include Subcategories: ALL
Saved

Front End... and so on.

[danielsmink]

Thanks @bertmert I'll have a look at it today.

[joomla-cms-bot]

This PR has received new commits.

CC: @bertmert

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[danielsmink]

Fixed both bugs with tagid 0. Removed the label all together so it's the same as in the backend.

Thanks for testing @bertmert

[ghost]

I have tested this item 🔴 unsuccessfully on c3b4f1a

Success for Protostar template.

But not for Beez3 template.

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[joomla-cms-bot]

This PR has received new commits.

CC: @bertmert

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[danielsmink]

Thanks again @bertmert for some reason I assumed the standard templates wouldn't use overrides. It's fixed now.

[joomla-cms-bot]

This PR has received new commits.

CC: @bertmert

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[ghost]

I have tested this item ✅ successfully on 143ba26

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[genesisfan]

I have tested this item 🔴 unsuccessfully on 143ba26

Both templates Beez3 and Protostar been tested.
The principle works, just not quite logical IMHO.

When you select a tag with result 'There are no articles in this category...' then you are not able to select a different tag. The selection bar disappears. Only when you select the menu item again.

Secondly could you add a search option in the tags list? Quite useful when you have a lot of tags.

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[ghost]

When you select a tag with result 'There are no articles in this category...' then you are not able to select a different tag. The selection bar disappears. Only when you select the menu item again.

That's not a misbehavior related to this PR. Try with title filter and search for nonsense. Same behavior.

[genesisfan]

Agree for the search part. It's by design.
But, when the title filter stays, in cause of "there are no articles..." it is more sophisticated.

[danielsmink]

@genesisfan I could fix that in a separate PR. Likewise with searching for a specific tag, I guess we could add in Typeahead. But the idea was same behavior as the backend. Which this PR solves.

[danielsmink]

@genesisfan @bertmert how do you guys suggest we continue? As I said I'm more then happy to make the other alterations but I don't feel they are part of this PR.

[ghost]

how do you guys suggest we continue?

I'm just a "helping user" and have nothing to decide here but from my point of view you have 2 successful tests and @genesisfan should differentiate and test again
with this in mind:

• the problem that filter fields disappear if no items found is as old as Joomla I think. Not a fault of this PR and MUST be fixed otherwise.
  (And should be fixed in all Joomla core components with frontend list views together (consistency).)
• The second part is an additional feature. All you need is a line

JHtml::_('formbehavior.chosen', 'select');

in a template override of list view if you want this feature
Voilà:

BUT: I've asked the question some time ago if Beez3 should get always "chosened" selects or if it's prefered that not. If yes it would be easy. Just add line above to a relevant core file. BUT: I never got an answer. Thus I wouldn't add this feature to this PR if it would be mine. Know what I mean? Sometimes smaller steps are the faster ones ;-)

EDIT: See:
#8919 (comment)

But Beez3 normally doesn't use "chosened selects". There it's a really strange behavior to have sometimes this or that style. I don't know a way to suppress already loaded formbehavior.chosen. ... Please advise! Should Beez3 use "chosened selects" ON ALL PAGES or not? Sometimes it's forced to use them sometimes not.

[genesisfan]

I have tested this item ✅ successfully on 143ba26

> the problem that filter fields disappear if no items found is as old as Joomla I think. Not a fault of this PR and MUST be fixed otherwise.

Agree @bertmert and therefore successfully tested.
It would be nice if this normal behavior of the filter disappears could be fixed in another PR.

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[danielsmink]

Thanks for testing @genesisfan !

[brianteeman]

Looks great - RTC

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[danielsmink]

@brianteeman looks like the bot won't tag it :-/

Edit: and then it instantly did :-)

[stefanpolzer]

Hy danielsmink, thx for this, I working on a Project where I will us it.
Can anybody tell me if this it already in the 3.5.0-RC Version?
I could not find it there.

[brianteeman]

@stefanpolzer No its not it was only tagged rtc after the release of RC

[rdeutz]

@danielsmink cloud you please check the merge conflicts, thanks