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Initial Setup Properties |
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Properties for Substitution |
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Runtime Properties |
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Methods |
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Events |
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Overview
The WebQuery control retrieves information from a web site. The control accesses the URL address specified by the ISourceURL property. It searches the web page for a specified text string, with the ability to use tag attributes to limit the search. Once the page has been retrieved, additional searches can be done without reloading the page.
While the page is being retrieved from the web site, the WebQuery control can wait (silently) or exit the InProgress exit node to allow the call-flow to play greetings or ads until the page is fetched.
The page is fetched using a HTTP GET request method.
Entry Nodes
Main Entry
This is the main entry: it fires the Enter event of the control allowing you to change all the properties mentioned above and then issues the URL request.
If the control's InProgress exit is connected, then it exits from it before getting any data. However, if this exit is not connected, then the channel thread blocks here waiting for the page fetching to end.
Next Entry
This entry is used to search for the next criteria match in the currently fetched page. Entering this does not reissue any http request.
Note: Changing any property and entering the Next entry is not recommended.
CheckBack Entry
Enter this entry only if you exited from the InProgress exit. The control will check for two things: if the page has become available and how much time has elapsed since the fetching started. This entry behaves exactly as if you were still in the control in the Main Entry and never exited.
Exit Nodes
Done Exit
WebQuery was entered from the Main, Next, or Checkback entry. It exits from the Done Exit if and only if the page is loaded, no timeout happened, and there is a match.
InProgress Exit
The control exists from here only if it were connected to another control. This exit is used to do other things while the MSHTML library is fetching the page.
Important: If you exit from here, sometimes the call-flow will return frequently to the CheckBack Entry in order for the page to load completely.
Timeout Exit
The control exits from here if the page loading is timed out.
Error Exit
A general error exit.
NotFound Exit
This exit is visited when no matching result is found on the successfully loaded page.
NoMore Exit
This exit is visited only when you enter from the Next Entry and no more matching result is found.