Building Applications - eXist: A NoSQL Database and Application Development Platform - page 233

• mode defines the permissions on the loaded files in permission string format (e.g.,
rw-rw-r-- ). For XQuery files, the x permission will be automatically set in
addition.
In most cases you'll want your package loaded under admin privileges. Since the
Package Manager runs as admin anyway, you don't have to specify the admin
password. So, the usual contents of the permissions element are:
<permissions user= "admin" password= "" group= "dba" mode= "rw-rw-r--" />
The Prepare and Finish Scripts
In repo.xml , in the prepare and finish child elements, you can define two optional
XQuery scripts that run directly before (preinstall) and directly after (post-install) a
package is installed. Typical tasks for these scripts could include:
• Installing indexing or other definitions in a collection.xconf resource under‐
neath /db/system/config . There are two approaches you can take:
— Do this in the preinstall script (before loading the data). The data will then be
indexed on load.
— Do it in the post-install script and programmatically reindex (using the exten‐
sion function xmldb:reindex ). This is how the package for the topic's exam‐
ple files works. There is some generic code for this in the /db/apps/exist-book/
installer/installer.xqm module that could be reused in other packages if so
desired.
• Creating users and groups for your application (or checking whether they exist).
• Creating data collections and resources outside the application's collection
structure.
Both the pre- and the post-install scripts can make use of some external variables
whose values will be provided by eXist during execution. The variables available for
you to declare in your query's prolog are:
declare variable $ home external ;
declare variable $ dir external ;
declare variable $ target external ;
$hom The directory where eXist is installed (i.e., $EXIST_HOME )
$dir The directory containing the unpacked version of your packages .xar file