EZP-31295: Unable to use default empty custom CSS class in the OE

[SerheyDolgushev]

Question	Answer
Tickets	EZP-31295
Bug fix?	yes
New feature?	no
BC breaks?	no
Tests pass?	yes
Doc needed?	no
License	GPL-2.0

In some cases custom CSS class is optional, and it should be possible to not select any. Right now UI is not allowing to do that. As a workaround, we added an empty custom CSS class and made it default, but it was causing some errors.

Steps to reproduce

1. Setup custom CSS classed and default empty CSS class:

   system:
       default:
           fieldtypes:
               ezrichtext:
                   classes:
                       paragraph:
                           choices: ['', custom-paragraph-1, custom-paragraph-2, custom-paragraph-3]
                           default_value: ''
                           required: false
                           multiple: false
   

2. Open the Online Editor and try to update the custom CSS class for the paragraph.

Actual result

Following JavaScript error is thrown:

Uncaught DOMException: Failed to execute 'remove' on 'DOMTokenList': The token provided must not be empty.
    at ButtonAttributesUpdate.clearClasses
    ...

Expected result

Custom CSS class should be changed, and it should be possible to change it to the empty default value at any given time.

Checklist:

• Coding standards ($ composer fix-cs)
• Ready for Code Review

[dew326]

Thanks for another contribution.
Looks ok, just minor code style.

[dew326]

Suggested change

	this.classes.choices.forEach(className => {
	this.classes.choices.forEach((className) => {

[SerheyDolgushev]

@dew326 done in 0ecdbd0

[dew326]

@SerheyDolgushev could you prepare PR for ezplatform-richtext to fix it in 3.0?

[dew326]

PR for master created: ezsystems/ezplatform-richtext#104

[micszo]

QA Approved on eZ Platform EE v2.5.8 with diff.

[SerheyDolgushev]

@dew326 sorry, I was out for a few days. And seems like you just made a PR for master.

[lserwatka]

Could you merge it up?

[dew326]

@lserwatka done