Posts Tagged ‘Tips’

Checking AIM Capabilities Via JavaScript

Thursday, February 12th, 2009

Open AIMWith so many different AIM clients out there, how can we tell if a client supports a particular feature? The answer is capabilities. Each screen name has a list of capabilities (GUIDs) that are asserted by the client and plugins.

How can I read these capabilities in the AIM SDK, you might ask? You can see what a user supports via the AccUserProp_Capabilities property and what the client asserts via the AccSessionProp_Capabilities property.

Here is a dump of the capabilities property for one of my screen names as seen by my CoreWitness plugin:

  AccUserProp_Capabilities = Array { ...GUIDs removed from trace here... } 
      {09461345-4C7F-11D1-8222-444553540000} = Direct IM
      {748F2420-6287-11D1-8222-444553540000} = Chat
      {09461343-4C7F-11D1-8222-444553540000} = File Transfer
      {67753137-6A38-6C77-4672-762D49755071} = UUID of a plugin: 'Gus Verdun's Core Test Plug-in (Dev)'
      {09461346-4C7F-11D1-8222-444553540000} = Buddy Icon
      {9FD3969B-84CB-45C1-B5DF-72DF5FAAB98E} = RX-Plugin

The AIM SDK returns an array of GUIDs in string form for those two properties. The CoreWitness plugin will automatically map the GUIDs to friendly names. When it encounters a GUID it does not recognize, it scans to see if the GUID matches that of any plugin you have installed. Yes, you can assert your plugin’s key as a capability if you want too. However, this is not required even thought your plugin’s key is reserved for you. I chose long ago to assert a different GUID as a capability for my RX-Plugin as you can see above. The capability is used to change the behavior of the IMpulse feature when both users have the RX-Plugin installed.

The AIM SDK always returns VB arrays in JavaScript so you must convert them to a JS array by using the toArray() method. Here is one way you can test to see if a buddy supports a particular capability:

// Test to see if buddy (IAccUser) has the RX-Plugin capability asserted
function HasRXPlugin(buddy)
{
    if ( SafeHasCapability(buddy, '{9FD3969B-84CB-45C1-B5DF-72DF5FAAB98E}') )
        alert('yes');
    else
        alert('no');
}
 
// cap must be in upper case.
function SafeHasCapability(user, cap)
{
    try {
        return  user.capabilities.toArray().join('').indexOf(cap) >= 0;
    } catch ( e ) {
        return false;
    }
}

The first function calls the more general function to test if the buddy has the capability asserted by my RX-Plugin.

You can use capabilities in your plugins for anything. They can be used to indicate that something is “on”, “selected”, etc. You can even have more than one—within reason. The AIM Vote ‘08 plugin uses capabilities to indicate your vote for McCain or Obama and then tallies up the number of buddies with either of those capabilities.

Centering an AIM Module Plugin Window

Wednesday, February 4th, 2009

The window.external.window.center() is a handy function in the AIM Modules API that you can use when all you want to do is center a window without regard for the buddy list. If you want to center a plugin window in a way that accounts for the buddy list, then you will need to write your own function. A solution I actually needed in one of my plugins.

In order to center a window, we need to know what monitor it’s in. Here is a function that returns the monitor for a given window:

function findMonitorForWindow(tWnd)
{
    // loop over all monitors until we find the one where
    // the top left corner of the target window is in
    for (var i=0; true; i++) 
    {
        var m = client.findWindow('_monitor'+i);
        if (m.exists)
        {
            if ( tWnd.x >= m.x && tWnd.x < (m.x + m.width) &&
                 tWnd.y >= m.y && tWnd.y < (m.y + m.height) ) 
                return m;
        }
        else
            break;
    }
    // default to first monitor
    return client.findWindow('_monitor0');
}

NOTE: ‘client’ above is the window.external.client object that has been assigned to a global variable.

Now that we can find the monitor for a given window, we can center the window any way we want in this monitor. Here is a function that centers the window over the region not occupied by a docked buddy list.

function BuddyListAwareCenterWindow(tWnd)
{
    // The standard center function:
    var center = function(o,w,n) { return (o + ((w-n)/2) ); }
 
    var tWndMonitor = findMonitorForWindow(tWnd);
    var blWnd = client.findWindow('_buddylist');
    var blWndMonitor = findMonitorForWindow(blWnd);
    var blWidth = 0, blOffset = 0;
 
    // are both windows in the same monitor?
    if (tWndMonitor.monitorIndex == blWndMonitor.monitorIndex)
    {
        // adjust centering width if bl is docked on either left or right
        if (blWnd.x == 0 || (blWndMonitor.width - blWnd.width) == blWnd.x )
            blWidth = blWnd.width;
        // adjust centering offset if docked on left.
        if (blWnd.x == 0)
            blOffset = blWnd.width;
    }
 
    tWnd.move( 
        center(tWndMonitor.x +  blOffset, tWndMonitor.width - blWidth, tWnd.width),
        center(tWndMonitor.y, tWndMonitor.height, tWnd.height) );
}

There are some edge cases like when a window is bigger than the space it’s centered on, but this solution should help you get started.

How to Debug a C++ AIM Plugin

Friday, January 30th, 2009

Here are some tips on how you can debug your own C++ plugins for AIM.

First, I suggest you get about three or four screen names. Developing C++ plugins requires a lot of client re-starts which can get you log-in rate-limited very fast. Also don’t forget to take advantage of the edit and continue feature in Visual Studio while debugging since this will save you a login cycle.

Debugging a plugin is a little bit different than an entire application. I typically compile my plugin in Visual Studio. Then launch AIM using my IM control panel program. Incidentally, this app also lets me kill AIM completely which I need to do when I crash or want to force a restart. When I see the login window, I attach the debugger via the attach to process dialog (CTRL+ALT+P). Look for the aim6.exe process and attach to it. I then set my breakpoints and log in.

NB: There are two things you should note with the debugger. First is to make sure you are debugging native code and not script; very easy to miss. Second, is that your breakpoints will appear as inactive at this time since the plugin is not loaded yet. As long as you make sure you are debugging native code you should not have to worry too much about the breakpoints being disabled. They should light up once you are online.

AIM has its own crash handler that collects stack trace and other information to send along. Since I am developing my own plugin, it makes no sense to report these crashes to AOL. You can temporarily disable it by renaming the C:\Program Files\Common Files\AOL\AOLDiag\tbdiag.dll file to something else. Without it, all crashes get handled by Windows which lets you attach the debugger at the crash point.

With just these few tips you should be able to get started on debugging your own plugins easily.

Pushing Buddy Updates via JavaScript

Wednesday, January 28th, 2009

Here is the JavaScript edition of my previous post:

function SafePushTestFeed(session)
{
    try {
        manager = session.buddyFeedManager;
        myitem = manager.createBuddyFeed();
        myitem.feedTitle = 'Feed Title';
        myitem.feedLink = 'Feed Link';
        myitem.feedDescription = 'Feed Description'; 
        myitem.feedPublisher = 'Feed Publisher'; 
        myitem.itemTitle = 'Item Title';
        myitem.itemLink = 'Item Link';
        myitem.itemDescription = 'Item Description'; 
        myitem.itemGuid = 'Item Guid';
        myitem.itemCategory = 'Item Category';
        manager.push(myitem);
    }
    catch ( e ) 
    {
        // You can look this number up in the 
        // CoreWitness Symbol Lookup Dialog
        trace("Exception HRESULT=" + e.number);
    }
}

The buddyFeedManager is a property of the IAccSession interface. In C++ you access properties via the get_Property(prop, value) or get_XXX methods. However, from JavaScript you can access any property including the AccXXXProp_ ones by just using the property’s trailing name (everything after the AccXXXProp_ or get_). Property and method names are not case sensitive in JavaScript.

You can read more about the these interfaces by searching for the interface reference pages on IAccBuddyFeed and IAccBuddyFeedManager.

Closing a Docked AIM Module Window

Thursday, January 22nd, 2009

It has come to my attention that you can’t programmatically close an AIM Module window while it is docked. The window.external.window.close() method does not appear to work in this situation.

For now, the only workaround is to un-dock the window before closing it:

// global aliases as described in a prior post
wnd = window.external.window;
client = window.external.client;
prefs = window.external.prefs;
 
function CloseDockedWindowWorkAround()
{
    // un-dock the window briefly.
    if (client.apiVersion == 1)
       client.docked = false;
    wnd.close();
}

This workaround will be needed in AIM 6.8 through AIM 6.9 Beta 2 (they all return an API version of 1).

I will get this issue fixed in the next AIM 6.9 beta since the plugin window is briefly shown in its undocked state before disappearing.

NOTE: This only applies to the dockable plugin window. All extra windows opened by the plugin can be closed without this workaround since those windows can never be docked.

Tips on Developing AMO Plugins

Monday, January 19th, 2009

AIM 6.8 and the AIM 6.9 betas all support AIM Modules. These are HTML and JavaScript based plugins that have full access to the Open AIM API plus client level services like HTTP requests and window management.

One of the nicest aspects of AMO plugins is that you can install and uninstall them without having to sign off. This is fantastic from both a development and user perspective.

I recommend that you get an extra plugin key for developing plugins. Once you publish version 1 and set a finger print (optional) you will not be able to develop your plugin further with that key since only plugins with the registered fingerprint will be allowed to load. The solution to this is to get an extra key that you use for development purposes. Don’t forget to change to the deploy key before publishing.

Here are five tips to help get you started on developing your first plugin:

1 You can install a plugin by running the .amo file. I typically do “start plugin.amo” from the command line or make file. AIM registers itself as a handler for this file extension. You can install a plugin even while offline.

1You should enable the debugging setting in IE for other apps. This helps you attach the JavaScript debugger during development and warns you about unhandled exceptions. With debugging enabled (i.e. not disabled), you can insert “debugger;” statements in your code to trigger the debugger. Go to the Internet Settings control panel and uncheck the highlighted option is to do this.

Enable IE Debugging for AMO plugins

1Create aliases for the window.external.* objects. This makes it easier to use these by assigning them to a variable. I put these at the top of my JavaScript file:

debug=1;
prefs = window.external.prefs;
client= window.external.client;
wnd = window.external.window;
plugin= client.pluginInfo;

1Set the AMO_TRACE_ENABLE environment variable to “true” in order to use the window.external.client.trace(msg) function that sends output to the debugger. I do it via the Environment Variables dialog in the System Properties control panel (Windows+Break key, click on Advanced tab, then “Environment Variables” button.)

Set AMO_TRACE_ENABLE environment variable

I also create a trace function that helps me leave trace message that are suppressed when the plugin is deployed. This is a good practice. Note that this code uses the global variables ‘debug’ and ‘client’ that I set up the previous tip. Remember to set debug=0 when you deploy your plugin.

function trace(m)
{
    if (debug)
        client.trace(m);
}

1If your plugin fails to install for some reason, make sure your plugin.xml file is well-formed and that the minimum required attributes are there. Here are the minimum. The UUID must be your key with {}’s:

<?xml version="1.0" encoding="utf-8"?>
<plugin 
    schema     = "1"
    type       = "html"
    uuid       = "{00000000-0000-0000-0000-000000000000}"
    name      = "any name you want"
    .
    .
    .
</plugin>

Bonus Tip: See my posts tagged with “tips” for more.

Reading an AIM SDK Preference via JavaScript

Thursday, January 15th, 2009

Last year AOL released AIM 6.8 which is the first version of AIM to support plugins written in HTML and JavaScript. These plugins are called AIM Modules. They are a zip file that contains the plugin’s manifest, content, and code with a .amo extension. NOTE: a.m.o (addons.mozilla.org) and AMO plugins are not related.

A complete introduction to AMOs is beyond the scope of this post. You can read more about the AIM Module Plugin API on the AIM Developer web site. I have written a few of these plugins under the AMO Factory brand.

In my previous post, I demonstrated how to read a preference via C++. Here is a sample that accomplishes the same in JavaScript.

// Make a shorter name for this. See the AMO API for docs on this class
client = window.external.client;
// Get the primary IAccSession object. 
// (primary is the first account that signs on.)
session = client.primarySession;
// Get the IAccPreferences object for this session
prefs = session.prefs;
 
// See the IAccPreferences API
function safeGetPref(spec, default)
{
    try {
        // method names of AIMcc objects are not case sensitive.
        return prefs.GetValue(spec);
    } catch (e) {}
    return default;
}
 
function canDisclosePluginsToBuddyFeed()
{
    return safeGetPref("aimcc.privacy.disclosePluginsToBuddyFeed", 
        false);
}
 
if (canDisclosePluginsToBuddyFeed()) 
{
    alert('preference is true');
}

I recommend that you use try/catch blocks around AIMcc method calls since they can return COM error results that throw exceptions in JavaScript. The safeGetPref() function takes care of this and returns the default value if AIMcc returns any error.

TIP: The e.number property in the catch block has the HRESULT as a negative number. You can find the symbolic name for this error via the Symbol Lookup dialog in my CoreWitness plugin. Just enter the number in the find box to do the reverse lookup.

Tip on Finding Preferences in Open AIM

Tuesday, January 13th, 2009

Every now and then I have to look up a preference specifier in AIM in order to use it in a plugin.

For example, the other day I wanted to determine if the user has enabled the pushing of AIM Plugins to their buddy feed. I usually check in technote 10 on preferences in the AIM SDK technotes. However, you can also do this empirically in AIM with my CoreWitness plugin. All ‘aimcc.*’ preference changes will cause the OnPreferenceChanged event to fire on all listeners so you can simply make a change in the client to see what preference specifier is changing.

To make it easier, the latest version of my CoreWitness plugin lets you filter the messages being logged by pressing the * button in the title bar. To filter the log to just the OnPreferenceChanged event, open the filter dialog and proceed as follows. Click on the ‘clear all’ button and then start typing the word “preference” in the filter edit box until you see “OnPreferenceChange” appear in the list. Select this event and click OK. Here is a screen shot of this step:

DAccEvents Monitor Filter

After doing the above, I changed the ‘I have installed a new AIM Plugin’ check box in the privacy tab of AIM 6.9’s Settings and clicked apply. Here is a screen shot of my results:

As you can see the preference is called ‘aimcc.privacy.disclosePluginsToBuddyFeed’. Finding the preference specifier is only the beginning. I will cover how to read it in a future post.

NOTE: This will only work for aimcc.* preferences. So it is possible that you can make a change in the settings that does not get notified via OnPreferenceChange because it is internal to the client. Internal preferences are not available to pluigns at this time.

AIM Blast Power User Tips

Sunday, January 11th, 2009

By now the web is buzzing with comments on AIM Blast. Don’t know what it is? AIM Blast is like an email list for IMs. You can create a permanent “blast group”, invite your friends, and then send/receive messages to/from all who are online at the time. It’s that simple. See the AIM Blast page for more details.

Blast groups appear as an automatically managed group in your buddy list. Once you have a blast group, just send an IM to the []-bracketed blast group buddy name.

You might have noticed that you need to reply with //1 or //2 when you receive an IM with the invitation to a blast group in order to accept or decline the invitation. It turns out there are many more commands that you can send to the blast group once you have joined.

Here is a list of additional commands you can send to blast group (NOTE: Most of these commands are handled by the host w/o being relayed to the blast group members):


//off
Stop receiving IMs. Use this when you are not interested in the current conversation. Don’t forget to send //on since this is in effect until then.

//on
Start receiving IMs again.

//invite name
Invite name to AIM Blast. An easy way to do this without having to go through the AIM Blast web site.

//history
Display last 10 IMs. This is an excellent way to check if you missed any recent blast messages.

//stats
Display stats

//soundon
Turn buddy sound on for the group

//soundoff
Turn buddy sound off for the group

//help
Get the list of // commands.

I found one more command that is not listed in the //help command and that is the //roll command to roll 2 six-sided dice; great for playing games and making random decisions via AIM Blast.

One last tip is that my Link Buddy plugin (also available from the AIM Gallery) has a link that gets you authenticated access to the AIM Blast web site so you don’t have to enter your password once you are signed-in to AIM.

Link Buddy Plugin