Providing a registered service

If you want to let users register your email, address book, or To Do service in the Service Registry, display a card that lets the user request the following URL:

device:home/register?svc=svc&url=url&name=name

Argument	Description
svc	The registry category for your service (Email, AddrBook, ToDo, or FaxHTML).
url	The URL for your service.
name	The service name that the device displays to the user.

For example, suppose you want users to be able to register your service as an address book and your service has the following URL:

http://myaddr.foo.com/addrbook.cgi

You could use an HDML deck similar to the following to register it:

<HDML VERSION=3.0>
<ACTION TYPE=ACCEPT TASK=GOSUB LABEL=YES
    DEST="device:home/register?svc=AddrBook
        &url=http%3a%2f%2fmyaddr.foo.com%2faddrbook.cgi
        &name=MyAddr"
    NEXT=#somedeck.hdml>
<ACTION TYPE=SOFT1 TASK=CANCEL LABEL=NO>
<DISPLAY>
    Register MyAddr as your address book?
</DISPLAY>
</HDML>

FIGURE  7-6.     Allowing the user to register a service

To properly implement a registered service, it must support the minimum functionality and interface for its service category (described in Sending email with the registered email service for email services, Using the registered address book service for address book services, and Using the registered To Do service for To Do services).

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Security issues for registered services

In addition to supporting the functionality and interface described in the sections above, registered services should observe security precautions to protect users and themselves. The following are some guidelines to follow when you implement a service that the user can register:

• A registered email service should display any message another service has asked it to send, allowing the user to confirm it. This ensures that a malicious service cannot send a message without the user's knowledge.

• A registered address book service should display any address entry it is about to add at the request of another service.

• For secure information, the service should employ username-password and certificate authentication.