Manual:ResourceLoaderSkinModule

ResourceLoaderSkinModule is a special kind of module that provides boilerplate styles to help you build a working skin. It can be used by registering a module in your skin's skin.json file like so:

For skins deprecating the legacy feature
Skins using the `legacy` feature should instead enable the following features

Before: After: When making this transition please report any bugs and heed the following advice...

Enabling the `normalize` and `elements` feature is recommended
Without this, you may notice some elements look a little off, particularly in print mode. However if your skin provides alternatives you can ignore.

visualClear
Skins making use of `visualClear` should instead use the clear fix mixin. To aid migrating add the following style to your skin:

Skins should define a red link color for links to non-existent pages.
Skins using the legacy feature currently get red link color of. Skins that use the content-links feature will get a color of. In future skins will be able to define a LESS variable to override it.

For skins that do not import either, these links will appear as normal links.

Suggested:

Skins need to style their edit links if they are not including the `interface` feature.
If a skin does not include the `interface` feature, it may make sense for the skin to copy across the content of the deprecated styles inside resources/src/mediawiki.skinning/interface-edit-section-links.less. Skins are encouraged to be opinionated about how edit links display and to revise these as needed.

Skins using `error`, `warning` or `success` classes should provide their own styles

 * Consider using `mw-messagebox`, `mw-warningbox` and `mw-successbox` instead and there associated Html::warningBox/Html::messageBox PHP classes.

Check your skin when printing
please check your print stylesheet, in particular for UI regressions relating to the footer.
 * Only skins using the interface feature will hide elements with the `printfooter` class automatically.
 * Skins using the #footer element with `interface` feature would previously get the footer displayed in a gray box. This is now the responsibility of the skin

Note about directionality
Previously the `legacy` feature provided the following rules: These rules are no longer necessary. All elements with these classes should have a `dir` HTML attribute to provide this rule.

Ajax spinners
There will no longer be defaults for mw-ajax-loader and mw-small-spinner. Copy the styles if they are needed.