ASP.NET C# Instant Messenger Status Determination – Akxl Labs « AJAX

ASP.NET C# Instant Messenger Status Determination – Akxl Labs

First, we need some functions to determine the status of an AIM user. I do this using the http://www.imwrapper.com/ service to get the status, based on the protocol.

The first function figures out if the user is online:

 1protected bool GetIMStatus(string screenName, string protocol)
 2...{
 3    protocol = protocol.ToLower();
 4
 5    string imStatusUrl = "http://www.imwrapper.com/" + protocol + "/"
 6                       + screenName + "/standard";
 7
 8    System.Net.HttpWebRequest imStatusRequest =
 9        (System.Net.HttpWebRequest)
10        System.Net.WebRequest.Create(imStatusUrl);
11
12    imStatusRequest.Accept="image/*";
13    imStatusRequest.AllowAutoRedirect = true;
14
15    System.Net.HttpWebResponse imStatusResponse =
16        (System.Net.HttpWebResponse) imStatusRequest.GetResponse();
17
18    return imStatusResponse.Headers["Content-Disposition"].
19Contains("online.png");
20}

GetIMStatus takes the following parameters, and returns a boolean, where true indicates that the user is online.

a screen name:

The screen name of the user to check. This value is generally case-insensitive, but this depends on the protocol.

a protocol:

The protocol to check on. Valid values are:

• AIM

• Yahoo

• MSN

• ICQ

• Jabber

• Skype

Note that these values are case-insensitive.

If that’s all you want to do, then you only need that function. But I wanted a snap-in, linked status indicator.

So, we need a function to display something based on this information. A big part of this will be the link location. Most protocols support a way to launch a message window to a user via a link, so we’ll need to construct a link for each protocol.

 1protected string GetIMStatusString(string screenName, string protocol)
 2...{
 3    return GetIMStatusString(screenName, protocol, "standard");
 4}
 5
 6protected string GetIMStatusString(string screenName,
 7                                   string protocol,
 8                                   string iconSet)
 9...{
10    string html = "";
11
12    try
13    ...{
14        protocol = protocol.ToLower();
15        iconSet  = iconSet.ToLower();
16
17        string imStatusUrl = "http://www.imwrapper.com/"
18                           + protocol + "/"
19                           + screenName + "/"
20                           + iconSet;
21
22        string statusString =
23         ((GetIMStatus(screenName, protocol)) ? "Online" : "Offline");
24        string linkStart = "";
25        string linkEnd   = "";
26
27        // jabber : xmpp:<sn>
28        // skype  : skype:<sn>?chat
29        // yahoo  : ymsgr:sendIM?<sn>
30        // aim    : aim:goim?screenname=<sn>
31
32        switch (protocol)
33        ...{
34            case "aim":
35                linkStart = "<a href=\"aim:goim?screenname="
36                          + screenName
37                          + "\">";
38                linkEnd   = "</a>";
39                break;
40            case "yahoo":
41                linkStart = "<a href=\"ymsgr:sendIM?"
42                          + screenName
43                          + "\">";
44                linkEnd   = "</a>";
45                break;
46            case "jabber":
47                linkStart = "<a href=\"xmpp:"
48                          + screenName
49                          + "\">";
50                linkEnd   = "</a>";
51                break;
52            case "skype":
53                linkStart = "<a href=\"skype:"
54                          + screenName
55                          + "?chat\">";
56                linkEnd   = "</a>";
57                break;
58        }
59
60        html = String.Format("<img src=\"{1}\" alt=\"{0}\" "
61                           + "align=\"absmiddle\" /> {3}{0} as {2}{4}"
62                            ,statusString
63                            ,imStatusUrl
64                            ,screenName
65                            ,linkStart
66                            ,linkEnd
67                            );
68    }
69    catch
70    ...{
71        // ...
72    }
73
74    return html;
75}

GetIMStatusString takes the following parameters, and returns the HTML for an icon for the client and status, a string describing the screen name and status, and (where possible) a link that will launch a message window to contact the screen name.

a screen name:

The screen name of the user to check. This value is generally case-insensitive, but this depends on the protocol.

a protocol:

The protocol to check on. Valid values are:

• AIM

• Yahoo

• MSN

• ICQ

• Jabber

• Skype

Note that these values are case-insensitive.

optionally, an icon set:

Check http://www.imwrapper.com/ for icon set names. The default is ’standard’, which is the first icon set on each list. All protocols also have ‘default’, which is the icon set actually used by the canonical clients. To find the icon set name, check the URL of the images in the set. For example, if an image’s URL is ‘http://www.imwrapper.com/images/icq/bevelled/offline.png’, the icon set is ‘bevelled’.

The string returned will render something like this:
IM: Offline

To make this code reusable, I made a custom control that can be snapped into a page. The control will render as the above status string. The source code that turns the above functions into a custom control is below. The control can be downloaded at the bottom of the page.

 1<%@ Control Language="C#" %>
 2
 3<script language="C#" runat="server">
 4    private string _screenName = "";
 5    private string _protocol   = "aim";
 6    private string _iconSet    = "standard";
 7
 8    public string ScreenName
 9    ...{
10        get ...{ return _screenName;  }
11        set ...{ _screenName = value; }
12    }
13
14    public string Protocol
15    ...{
16        get ...{ return _protocol;  }
17        set ...{ _protocol = value; }
18    }
19
20    public string IconSet
21    ...{
22        get ...{ return _iconSet;  }
23        set ...{ _iconSet = value; }
24    }
25
26    // [ THREE FUNCTIONS FROM ABOVE HERE ] //
27</script>
28
29<%= GetIMStatusString(ScreenName, Protocol, IconSet) %>

To use the control, you need two things:

The following code needs to be at the top of your page, to register the control.

1<%@ Register tagprefix="akxl"
2             Tagname="IMStatus"
3             src="/controls/IMStatus.ascx">

The next code places the control into the page output. You can also add another attribute, IconSet="<string>" to specify the optional icon set parameter. All attributes directly map to the parameters described above.

1<akxl:IMStatus id="akxlIMStatus"
2               runat="server"
3               ScreenName="ImTooSmartForMe"
4               Protocol="AIM" />

Here’s a live example of the control:

IM: Offline

akxl.net, C Sharp (C#), instant messanger

This entry was posted on Saturday, July 4th, 2009 and is filed under Chat. You can follow any responses to this entry through RSS 2.0. You can leave a response, or trackback from your own site.

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