Creating Page Extensions

This chapter describes the different Java classes and provides a step-by-step example of creating a page extension.

ILocaleLookup Java Interface
 
public interface com.cisco.csrc.ursub.ILocaleLookup
{
  public String getLocale(String computerIP, String modemIP);
}
 

public class SampleLocaleLookup
  implements com.cisco.csrc.ursub.ILocaleLookup
{
  public String getLocale(String computerIP, String modemIP)
  {
    // check if this is the university subnet.
    if (modemIP.startsWith("123.123."))
      return "University";
 
    // if no particular locale is found, use the default.
    return null;
  }
}
 

This example class determines if the subscriber is accessing User Registrar Subscriber from a university subnet. If it is, User Registrar uses the University locale, otherwise the class instructs User Registrar to display the default locale.

Tips While the class could return en (or whatever the configured default is) by returning null, the code leaves the default behavior controlled in User Registrar Administrator and thereby does not require a code change if the locale default is changed.

ILocaleChoices Java Interface
 
public interface com.cisco.csrc.ursub.ILocaleChoices
{
  public String[] getLocaleChoices(String computerIP, String modemIP);
}
 

This class returns null if all the locales should be displayed to the subscriber, otherwise it returns a string array containing a list of locale names to be presented. User Registrar ignores the names on the list that are not in the system's locale list.

public class ResidentialLocaleChoices 
    implements com.cisco.csrc.ursub.ILocaleChoices
{
  public String[] getLocale(String computerIP, String modemIP)
  {
    return new String[] 
      { "Residential_English", "Residential_Spanish" };
  }
}

public interface com.cisco.csrc.ursub.IUsernameLookup
{
  public String[] getUsername(
      ICWAFObject accountobj, ICWAFObject subscriberobj,
      ICWAFObject modemobj, ICWAFObject computerobj);             
}
 

public class SampleUsernameLookup 
  implements com.cisco.csrc.ursub.IUsernameLookup
{
  public String[] getUsername(
      ICWAFObject accountobj, ICWAFObject subscriberobj,
      ICWAFObject modemobj, ICWAFObject computerobj)
  {
    // build a string array for the results.
    String values[] = new String[2];
 
    // populate the account number and PIN in the array.
    values[0] = accountobj.getAttr("AccountNumber");
    values[1] = accountobj.getAttr("PIN");
 
    // return the values.
    return values;
  }
}
 

This sample class returns the account number and PIN of the subscriber as suggestions for the username and password. If User Registrar cannot find an appropriate suggestion, the code returns null.

For example, you could use the Username Check page extension to verify username uniqueness in an external e-mail server or you could use this page extension to provide a textual message containing a list of suggestions for alternative usernames.

public interface com.cisco.csrc.ursub.IUsernameCheck
{
  public String isValidUsername(String username);
}
 

public class SampleIUsernameCheck 
  implements com.cisco.csrc.ursub.IUsernameCheck
{
  public String isValidUsername(String username)
  {
    // check if the username is valid.
    if (username.equalsIgnoreCase("root") ||
        username.equalsIgnoreCase("webmaster"))
      return "You may not select '"+username+"' as a username.";
 
    // if the username passed all the checks, return null.
    return null;
  }
}
 

This sample class checks for certain special usernames and ensures that they are not selected. If a reserved name is selected, the code returns an error message explaining that the selected username is not available. When the username passes all of the checks, the code returns null to allow the subscriber to select the desired username.

For example, you could use the Hostname Lookup page extension to automatically generate a hostname from the computer's MAC address.

Tips By enabling a page extension that defaults the hostname and password to their respective values and then enabling Skip hostname selection, you could have subscribers skip the entire activate_device section and the subscriber would not need to understand what choosing a computer name means.

public interface com.cisco.csrc.ursub.IHostnameLookup
{
  public STring[] getHostname(
      ICWAFObject accountobj, ICWAFObject subscriberobj,
      ICWAFObject modemobj, ICWAFObject computerobj);             
}
 

public class SampleHostnameLookup
  implements com.cisco.csrc.ursub.IHostnameLookup
{
  public String[] getHostname(
      ICWAFObject accountobj, ICWAFObject subscriberobj,
      ICWAFObject modemobj, ICWAFObject computerobj)
  {
    // build a string array for the results.
    String values[] = new String[2];
 
    // populate the hostname and description in the array.
    values[0] = "comp-"+prepareHostname(modemobj.getAttr("MACAddress"));
    values[1] = "acc-"+accountobj.getAttr("AccountNumber");
  }
 
  // simple helper method that strips out illegal characters
  public String prepareHostname(String macaddr)
  {
    // create a buffer to use when stripping out the bad characters.
    StringBuffer work = new StringBuffer();
    
    // check each character in the mac address.
    for (int i=0; i<macaddr.length(); i++)
    {
      // check if this is a valid character.
      char c = macaddr.charAt(i);
      switch (c)
      {
        // check for illegal hostname characters.
        case ':': break;
        case ',': break;
        // if it isn't a bad character, add to the hostname.
        default:  buf.append(c);
      }
    }
 
    // return the processed string.
    return work.toString();
  }
}

For example, you could use the Hostname Check page extension to verify hostname uniqueness in an external name server or have it provide a textual message containing a list of suggestions for alternative hostnames.

public interface com.cisco.csrc.ursub.IHostnameCheck
{
  public String isValidHostname(String hostname);
}
 

public class SampleHostnameCheck
  implements com.cisco.csrc.ursub.IHostnameCheck
{
  public String isValidHostname(String hostname)
  {
    // check if the hostname is valid.
    if (hostname.equalsIgnoreCase("www") ||
        hostname.equalsIgnoreCase("mail"))
      return "You may not select '"+hostname+"' as a computer name.";
 
    // if the hostname passed all the checks, return null.
    return null;
  }
}
 

This sample class checks for certain special hostnames and ensures that they are not selected. If a reserved name is selected, the code returns an error message explaining that the selected hostname is not available. When the hostname passes all of the checks, the code returns null to allow the subscriber to select the desired hostname.

To compile and enable a page extension, do the following: