Webbots, Spiders, and Screen Scrapers, 2nd Edition

Non-calendar-based Triggers

Calendar events, like those examined in this chapter, are not the only events that may trigger a webbot to run. However, other types of triggers usually require that a scheduled task run periodically to detect if the non-calendar event has occurred. In the previous section, we talked about using email as a means to monitor webbots, but email can also be used to trigger webbots. For example, the script in the following listings uses techniques discussed in Chapter 14 to trigger a webbot to run after receiving an email with the words Run the webbot in the subject line.

First, the webbot initializes itself to read email and establishes the location of the webbot it will run when it receives the triggering email message, ...