When you want to add a button to the CMS but don't want LeftAndMain to apply jQuery UI button to it we add the `data-button="true"` attribute to our button.
The `onadd` function checks that this attribute does not exist before calling `this.button()`.
The `onremove` incorrectly checks that this attribute does exist before calling `this.button('destroy')`. This should be checking that this attribute does not exist, just like the `onadd` function.
What this causes is when you have a button with the `data-button` attribute a button is not created, but when you leave the page `destory` gets called on an item which doesn't exist. We end up with the following error:
> Uncaught Error: cannot call methods on button prior to initialization; attempted to call method 'destroy'
The other issue with this logic is buttons are never getting destroyed when `onremove` is called.
The whole issue is caused by a missing `!` in the if statement. This change adds it in to fix the problem.
Introducing <Tabs> component based on react-bootstrap
Better support for nested fields in FormBuilder
Tweaks to get FormBuilder working with frameworktest BasicFieldsPage fields
Added exception in FormBuilder when Component is defined but not found
Added check in SingleSelectField for empty value before adding one in
Added temporary workaround for CompositeFields with no name (another story to address the actual problem)
Added asset_preview_height for File image preview, matches the defined CSS max-height
Added documentation to DBFile::PreviewLink() method
* Remove interference of nested for__fieldgroup-item
* Adjust position of dropdown field
* Remove divider lines, adjust position of upload area
Clean up styles a bit too
* Adjust position of image
* Mostly css tidy up, added use of a few variables
* Toggle arrow was showing other icon because of icon height
* All buttons in toolbars remove margin below, adjust button link color
* Reorder sort and filter, add toolbar styles
* Add button styles to toolbar
* Remove some of the linting issues
* Added new panel variables
* Simplify variable
* Replace panel variable, insert media dialog positioning
* Update with new variable name, reduce space below toolbar
* Build
* Uploading file spacing, toolbar styles added
* Visual uploads, error upload fixes, edit details panel spacing
* Add toolbar to upload modal
* build
* Build
* increase width of pagination on gridfield
* Add height to uploading items only
* Build
* Added class back for beat test to pass
This caught us out recently where code did a strict type check for `myVar === undefined`.
The var was defined as `let myVar;`, without a value - so the check returned false (it's `null`).
To avoid this situation, we've decided to enforce declarations with values.
Note that preference should be given to single, immutable assignments via const where possible.
See http://eslint.org/docs/rules/init-declarations
Core.php can rely on composer’s autoloader now that classes are PSR-4
compliant.
If you stuck to the core modules, you could even remove ClassLoader’s
autoloader, but this would break any module that hasn’t been updated
to support PSR-4, so I’ve left it in.
In the future, it would be good to apply SilverStripe’s auto-loader
only to those modules that aren’t coded to use PSR-4, as it would
make class loading more predictable.
