Packaging:Web Assets

Scope

Web Assets are any static content that are shipped intact to web browsers, usually by web applications. These might be user interface frameworks, Flash video players, CSS frameworks, icon libraries, or lots of other possibilities.

If your package is primarily or solely shipped to a browser and not used locally, and is not JavaScript, it probably falls under these guidelines. JavaScript packages must follow the JavaScript guidelines in addition to these guidelines.

Rationale

There are lots of little bits shipped to browsers that aren't just JavaScript that typically have been bundled along with web applications up to this point. There are a lot of good reasons why we shouldn't bundle JavaScript this way, so it only follows that we should fix it for the rest of that kind of stuff too.

BuildRequires

To ensure the presence of the necessary RPM macros, all packages that provide web assets must have:

BuildRequires:  web-assets-devel

Requires

To ensure the availability of the necessary directories, all packages that provide web assets must have:

Requires:  web-assets-filesystem

Web application packages that ship configuration files for Apache HTTPd should ensure that the httpd configuration is installed as well:

Requires:  web-assets-httpd

RPM Macros

Macro	Normal Definition	Notes
_webassetdir	%{_datadir}/web-assets	The directory where all web assets are stored

Install Location

All packages that contain static content useful to different web applications must install into a subdirectory of %{_assetdir}. For instance, the jquery-ui package should install itself into %{_webassetdir}/jquery-ui.

All packages that contain static content that is only useful within the package in which they are shipped should continue to ship that content in the application's directory structure. However, they must follow the remainder of the guidelines outlined in this document.

Server Location

All HTTP daemons in the distribution should make %{_webassetdir} available in /_sysassets.

Therefore, if the fabulous-web-icons package ships an icon as %{_webassetdir}/fabulous-web-icons/important.png, you can include it in a web application with the following HTML:

<img src="/_sysassets/fabulous-web-icons/important.png">

Regardless, web applications may want to make subdirectories of %{_webassetdir} available under their own directory via aliases or symlinks for compatibility purposes or to eliminate needless deviation from upstream.

Content Guidelines

Web Assets must follow the general guidelines for content, unless stated otherwise in this document.

CSS

Pure CSS frameworks can be included as-is. CSS frameworks that use an alternative language that compiles to CSS, such as LESS, must compile to CSS as part of the build process. It is not acceptable to include pre-compiled CSS in Fedora packages.

Flash

Flash files (which typically use the .swf extension) must follow the general and licensing guidelines for code, not content, and must be built from source using a toolchain available in Fedora.

The Flash software needs to be compiled by a free software toolchain, such as swfc. Pre-built .swf files must not be included in Fedora packages. That compilation must be performed as part of the build process for the package.

If the flash software is not compilable using the toolchains inside of Fedora then the flash software cannot be shipped. In some cases you may be able to patch out use of the flash software (for instance, if it's a fallback in case the browser doesn't support HTML5) or you may have to give up on packaging the software until the flash software toolchain is enhanced to allow building.

Java applets

Java applets should follow the general and licensing guidelines for code, not content. Additionally, they should follow the Java guidelines, with the exception that the actual .jar file for the Java applet should be installed into a subdirectory of %{_webassetdir}.

Images

Images that are part of a larger Web Asset package can be included in that package's subdirectory. For instance, a UI library might contain images for its UI components in its subdirectory.

Web Asset packages that consist solely of images, such as a set of icons, may be shipped as their own package.

Fonts

All system fonts (available in %{_datadir}/fonts) are automatically made available in %{_webassetdir}/fonts/ via a symlink. For more information on packaging system fonts, see the font guidelines. Please note that [Web_Assets/Fonts|only fonts available in the Fedora package collection are made available on HTTP servers by default].

Please note that those guidelines prohibit packaging fonts elsewhere. There is no compelling reason to support other font formats, as most browsers that support web fonts support the TTF or OTF formats used by system fonts, therefore alternative web font formats like WOFF are prohibited.