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nsIRegistry on MXR

Other documentation: libreg source, reg.h in particular



It works like this.

var Cc = Components.classes;
var Ci = Components.interfaces;
var rc = Cc["@mozilla.org/registry;1"];
var rs = rc.getService(Ci.nsIRegistry);

Now you have the registry service.

rs.openWellKnownRegistry(2);  // 2 signifies the ApplicationRegistry, if I understand right
var st = rs.enumerateAllSubtrees(2);  // 2 signifies "common", see libreg source (reg.h) for info

Now you have an nsIEnumerator that can report the subtrees.

try {
  do {
    var data = st.currentItem();
    if( data instanceof Ci.nsIRegistryNode )
      print("nsIRegistryNode: " + data.nameUTF8 + " (" + data.key + ")");
  } while( Components.lastResult == 0 );
} catch(e) {}

Now, the output is something like:

Profiles (344)
Profiles/default (530)
Profiles/foo (1046)
Profiles/bar (1518)

The number inside the parenthesis is the "key." You can use this key with the rest of the nsIRegistry API (see MXR).

Now, I know from visual inspection that there's a key called "directory" for each profile. I don't know how to get the other keys' names automatically, but I do know how to look up the directory for a particular profile.

js> rs.getStringUTF8(530, "directory")  // 530: key corresponding with Profiles/default

The output is something like:



Can we change it?

js> rs.setStringUTF8(530, "directory", "/home/lion/somewhere/else")
js> rs.getStringUTF8(530, "directory")


Now, the only puzzle is: how do you save it?

js> rs.flush()  // this is not enough...

Perhaps if we quit with the XPConnect:appShellService, it will work.