Skin Files

Two separate directories must be in place within your Web server's file structure in order for an application skin to be served, a custom directory which contains params.txt and an imagejar. In addition, if you're going to serve multiple skins from your Web server, you'll need a separate params.txt directory and imagejar for each of them, plus a skins.txt file with information on all skin directories.

Creating a skin directory

For each application skin that you serve with your Droplets application(s), there must be a corresponding directory that contains the following files:

• params.txt;
• All GIF files that are to be served as a part of the skin.

These files can be in any directory within the Web server's directory structure that you wish. One way to group them is to create one directory per skin under the Web server's root directory; if you're serving multiple Droplet applications, though, you'll want to create a separate directory for each of these, with a sub-directory for each of their skins.

Regardless, each skin directory must be indicated correctly in the Droplets application's .drp file, which is generated by one of your Web pages; you should therefore make sure that the location of your skin directory matches the imagedir location as defined in your .drp-generating Web page. See Web site Integration for more information on this.

params.txt is a text file that gives the Droplets Client its appearance parameters. For more information on skinning, see the Skinning Droplets document for developers.

Important note: The entire look and feel of an application GUI is often determined by params.txt. Thus, if the Droplets Client fails to retrieve its application's params.txt file, the entire application may fail. The Client retrieves its params.txt from the imagedir parameter in its application .drp file. If the Client can't retrieve these skin files, it will display an error message that the URL cannot be accessed; see Web Site Integration for more information on how to set the imagedir variable.

The imagejar

The imagejar is a zipped version of the Skin directory structure. While it's not strictly required by the Droplets Platform, it is highly recommended because it greatly speeds application performance. Using it, applications fetch all of their graphics files in a single connection (as opposed to one HTTP connection per image).

If you do use an imagejar, you should have one imagejar for each of the skins that you are serving in your deployment, and they must be located in the root directory of your Web server (i.e. wwwroot for IIS). Typically, it has a descriptive name that associates it with its skin, for example:

depending on whether you're serving one or more Droplet applications.

Important Note: You can use most standard zip softwares in order to create your imagejar, but you cannot use Java's JAR software, as the Droplet Platform will not be able to unzip it.

If you do use an imagejar, you'll still have to have a separate skin directory with the application skins' params.txt file, but there will be no need to store the individual GIFs in the Web server directory.

Web server Permissions for imagejars: You must set your IIS permissions for all imagejar files to allow anonymous access. This is done through the IIS Manager by selecting the files Properties, selecting the "File Security" tab, Edit "Anonymous access and authentication control", and checking "Anonymous Access". If your application is loading slower than it should, double-check to make sure that this permission has been set.