Create Your Help Pages
UniHelp can display HTML files, ASCII Text Files and various web-compatible image and multimedia file formats. HTML pages are required to have either an ".html or ".htm" file extension. ASCII Text pages are required to have a ".txt" file extension. Images and Multimedia files are also required to include their respective file extensions in their filenames. UniHelp uses the file extensions to determine what kind of file it is and how to display it.
For styled help pages, we recommend using HTML for your help pages. HTML is displayed in REALbasic's HTMLViewer control, which supports most HTML tags and CSS styles!
Please keep in mind that the HTMLViewer control is merely a wrapper for the native HTML rendering engine on each respective OS platform. When run on Mac OS X, HTMLViewer is powered by Apple's WebKit (the same library that powers Apple's Safari web browser). When run on Windows, HTMLViewer is powered by the Internet Explorer engine. When run on Linux, HTMLViewer is powered by GtkHTML, the same library that powers the native OS help browser for many Linux distros.
HTMLViewer on Linux used to rely on the Mozilla engine, but as of REALbasic 2006r3 and higher, HTMLViewer now utilizes the GtkHTML library, which has a better guarantee of being available on most Linux distros and doesn't incur the same installation problems that frequently occur with Mozilla. Also, the GtkHTML library has a much smaller footprint than the monolithic Mozilla engine. One major limitation to the Linux GtkHTML library is that it does not yet support CSS styles, so while CSS will work great on Mac and Windows, CSS will not display properly on Linux.
If you encounter problems with UniHelp on Linux where the HTMLViewer will not work at all, the most likely culprit is that the GtkHTML library is not installed in the Linux distro you are using. Check with your Linux documentation to find out how to download and install the GtkHTML library. We tested UniHelp extensively on Ubuntu, where the GtkHTML library was already installed as part of the default system.
UniHelp supports either direct hyperlinks to image files or as inline images in HTML pages. The image file formats that UniHelp currently supports are the usual web-compatible formats: JPEG, GIF, and PNG.
Multimedia files (such as audio and video clips) are supported in UniHelp, but only if HTMLViewer's underlying HTML rendering engine supports the particular media fromats you are trying to play. This will probably vary from OS to OS. For example, QuickTime powers much of the multimedia playback in Apple's WebKit, but QuickTime is not available for Linux, so the GtkHTML library on Linux will rely on different technology to play media files. The typical media formats that are usually supported cross-platform are: MOV, MPEG, AVI, Flash SWF, MP3, MP2, AIF, WAV, and MIDI.
If you wish to distribute your help system as a single file, cross-platform Virtual Volume, you can place all of your help pages and related sub-folders inside a Virtual Volume instead of a standard help folder. You would still organize your help pages in a Virtual Volume the same way as you would in a standard help folder. For complete details on using Virtual Volumes with UniHelp, please see the Using a Virtual Volume page (within the "Advanced Topics" chapter).