Tab support for admin / content edit

[deanmarcussen]

This adds support for Tabs in the Admin - adapted from O1

Covers issues from SEO module #3214 , and also wanted for Sitemaps #3229, and original issue #1822

Validation remains outside the tabs

I also tweaked the CodeMirror sass to fix #3625

I included the content item id in the tab-pane id, to allow for multiple tab-groups to be rendered if this gets reused to move anything else into tabs (personally I'd love to see the different content localizations in tabs so you could flick between them when editing, but that's a whole nother piece of work!)

Styling is an extension of bootstrap tabs, so works with rtl.

In the example image above I've just used a placement.json file in the admin theme to move the TitlePart to create the second tab. As per O1 if there are no tabs the editor does not display the tab dialog, or wrap the content in a border.

Test placement.json file

{
  "TitlePart_Edit": [
    {
      "place": "Parts#Seo:0"
    }
  ]
}

Note : Not sure about the use of the localized string checks that I bought over from O1. Might make more sense to just wrap @tabname in a T(@tabName) - open to suggestions :)

[sebastienros]

We need a way to expose metadata in a file to describe new localized entries.
@lukaskabrt an idea about how we could do that? I am think of a custom extension to define strings that are localized, and their context. Even if it's in the standard pot format.

[lukaskabrt]

I think this is quite similar to the dynamic content localization described in #3607.

My idea is to define a provider, that return all localizable strings from the specific feature. We can call these providers at runtime and export all strings to a POT file. User provides translated PO files and either deploy them alongside other PO files or we might add another ITranslationProvider and let users import translation to the database. For rendering localizable strings we can use IStringLocalizer. I think it fits nicely into the existing infrastructure.

public class LocalizableString {
    public string Text { get; set; }
    public string Context { get; set; }
}

public interface ILocalizableStringProvider {
    IEnumerable<LocalizableString> Get();
}

There might be several providers e.g.

public class ZonesLocalizableStringProvider : ILocalizableStringProvider {
    // load all zone names
}

public class ContentDefinitionLocalizableStringProvider : ILocalizableStringProvider {
    // load all content type names and filed names
}

[scleaver]

Thanks for this @deanmarcussen

[deanmarcussen]

@sebastienros Not particularly responsive! Bootstrap nav-tabs just flex-wrap by default.

I've made them flex-column at sm so looks like this

They could go into a collapse if there were a lot of them (> 5) perhaps

Note - should do something with the actions buttons at sm as well!

[deanmarcussen]

@sebastienros What would you like me to do with this, regarding localization?

Remove references to LocalizedString until metadata localization is resolved and add support for localization later, or just leave this on hold and return to after more localization?

[sebastienros]

Don't localize any dynamic value until we have solved it.