#### 19.11.4 Executing browser commands for OmniHelp CSH calls

If the application that calls your OmniHelp project can execute system commands, the developer can have the application access the Windows Registry for the required browser command syntax, and use that command to open an OmniHelp topic file. With this method, you do not need redirect pages (see §19.11.3 Using redirect pages for OmniHelp CSH calls).

To see what is involved, check the Windows Registry for the correct browser command syntax (Start > Run > regedit):

1. Find the registered name of the default browser. Go to the following key:

   HKEY_CLASSES_ROOT\.htm

   and look at the first (Default) entry in the Data column. For example, for Firefox the default browser name is FirefoxHTML.

2. Find the exact command syntax for the default browser. Go to the following key:

   HKEY_CLASSES_ROOT\DefaultBrowserName\shell\open\command

   For example, for Firefox you would go to:

   HKEY_CLASSES_ROOT\FirefoxHTML\shell\open\command

3. Look at the first (Default) entry in the Data column. For example, the command for Firefox might be:

   C:\PROGRA~1\MOZILL~2\FIREFOX.EXE -url "%1"

In each call, the application should replace %1 in the browser command with the following type of file reference:

file:///path/to/_myproj.htm#IDH_contextID

where IDH_contextID is the content of a TopicAlias PI marker in DITA XML. Notice the three forward slashes in the file reference. This syntax should open the correct OmniHelp topic file.

Previous Topic: 19.11.3 Using redirect pages for OmniHelp CSH calls

Next Topic: 19.12 Merging OmniHelp projects

Parent Topic: 19.11 Setting up CSH for OmniHelp

Sibling Topics:

19.11.1 Specifying alias prefixes for OmniHelp CSH calls

19.11.2 Referencing OmniHelp topic IDs from an application

19.11.3 Using redirect pages for OmniHelp CSH calls

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