Enhancement Triggers

[This is preliminary documentation and subject to change.]

Each type of trigger sent to the Enhancement control has a specific format associated with it. The trigger format transmitted by the ipsend object is a string that contains three parts: a key or numerical identifier, the trigger data, and a checksum value. The key is separated from the data by white space, typically a space or tab character. The checksum value is surrounded by square brackets. For more information, see Trigger Checksum Value.

The format of a trigger is as follows:

"Key TriggerData[checksum]"

For example, the following string might be specified in a Nav trigger:

"2 bpc://www.microsoft.com/default.htm[BA7E]" 
 

Note  The checksum value is automatically calculated by the ipsend object when a trigger is transmitted. You do not need to specify checksum values when setting triggers in an enhancement stream. Because this value is added transparently, the following trigger topics display the trigger format you use to specify a trigger in the enhancement stream — in other words, the trigger format without the checksum value.

The following table lists the trigger formats currently supported.

Key Name Description
0 Error No action is taken.
1 Data Receives data using the specified transfer protocol.
2 Nav Displays a page. If a target is specified, such as a <FRAME> or <DIV> tag set, the page is displayed in that target.
3 Nav Same as the previous trigger. This key value has been kept for compatibility with earlier versions.
4 Script Runs the specified script.
5 TVCrossover Fires a TVCrossover event.
6 – 999 Reserved Key values reserved for future trigger functionality.
1,000 and up UserTrigger Sends a user trigger event.