In order to make configuring Railo a little easier, there are several constants, we call directory placeholders, that contain a certain value which might depend on either the system, the environment or the context. Here are the available placeholders in Railo.
| Placeholder name | Description |
| {railo-web} | path to the railo web directory typical "{web-root}/WEB-INF/railo" |
| {railo-server} | path to the railo server directory typical where the railo.jar is located |
| {railo-config} | same as {railo-server} in server context and same as {railo-web} in web context} |
| {temp-directory} | path to the temp directory of the current user of the system |
| {home-directory} | path to the home directory of the current user of the system |
| {web-root-directory} | path to the web root |
| {system-directory} | path to thesystem directory |
| {web-context-hash} | hash of the web context |
| {web-context-label} | a label that you can define in every railo-web.xml.cfm file |
Placeholders can be used in CFML als well like the following example shows:
<cfdump var="#expandPath('{railo-web-root}')#">
Railo 3.3: If you have configured Railo to place the configuration directories with the placeholder {web-context-has}, you may have wished that the resulting hashed directories would be a little more readable. You end up with a list of directories (each one a hash value of 32 bytes) which can be confusing. Therefore we have introduced the new placeholder {web-context-label}. Now you have the possibility to use this label as a path to the configuration files for each web context. In order to use this label you need to define it in every of the railo-web.xml.cfm configuration files. This is a chicken / egg problem, but it helps getting some order in the naming of the configuration directories.