HOWTO: Pass Parameters to an ActiveDoc

ID: Q186015

The information in this article applies to:

Microsoft Visual FoxPro for Windows, version 6.0

SUMMARY

You can pass an argument to an Active Document application in one of two ways, depending on how the application runs:

Hosted in the Internet Browser.

-or-
In Visual FoxPro or Visual FoxPro run-time.

MORE INFORMATION

Hosted By Internet Explorer

When the Active Document application is hosted in an Internet browser, any arguments specified are sent directly to the Run event of the ActiveDoc class. The following line of code is included as the first line in the Run event by default:


   LPARAMETERS cHyperLinkTarget

The Run event can only receive one parameter. However, you may parse this one parameter into multiple parameters once received by the Run event. Multiple parameters may be strung together with a delimiter such as a plus sign. The developer needs to code the application to look for the delimiter character when parsing out multiple parameters.

Passing an argument to an Active Document application uses the following syntax:


   HTTP://MYIIS/MyADoc.app#MyParamVal

Everything, starting with and including the pound sign passes into the Run event as a parameter. Therefore, you need to remove the pound sign from the parameter.

Parameters can only pass to an Active Document application that is hosted in a Web browser if the Active Document application is being served by a Web server such as Microsoft Internet Information Server. A parameter cannot pass to an Active Document application that runs in the browser with the Run Active Document command from Visual FoxPro's Tools menu. Nor can a parameter pass to an Active Document application if you type the location directly into the Web browser's address bar. For instance, you can run an Active Document application by typing the following into Microsoft Internet Explorer's address bar, but you cannot pass any parameters:

C:\TEST\MyADoc.app

In Visual FoxPro

When the Active Document is hosted in Visual FoxPro or the Visual FoxPro run-time, the arguments pass to the Init event of the ActiveDoc class. The syntax to run an Active Document application in the Visual FoxPro development environment is as follows:


   DO MyADoc.app WITH cMyParamVal

MyADoc.app is the name of the Active Document application, and cMyParamVal is the value of the parameter.

Parameters cannot pass to the Active Document application if you run the application from the Run Active Document command on the Tools menu, whether it is hosted in Visual FoxPro or not.

Tips For Coding The ActiveDoc Class

Since there is a difference in where these parameters are being received, some tips to help avoid problems when creating an Active Document application that utilizes parameters are described below:

Use custom properties in the ActiveDoc class to store the parameter values. If you are passing the parameters to the form called in the Run event, when the application is run through the Visual FoxPro shell, you reduce the code needed to reference the parameter.

You create Custom properties by selecting New Property from the Class menu when in the Visual Class Designer or in the Edit Property/Method dialog box also accessed from the Class menu.
Use the ISHOSTED() and GETHOST() functions to determine if the Active Document application is being run in FoxPro or hosted in Internet Explorer.

ISHOSTED( ) returns true (.T.) if an Active Document is hosted in an Active Document container such as Microsoft Internet Explorer.

GETHOST() returns an object reference to the container of an Active Document. You can then use the name property to determine the name of the container.
Creating ActiveDoc classes can only take place in the Visual Class Designer. You cannot create an ActiveDoc class with program code.

The following are sample Init and Run events from an ActiveDoc class that use Parameters. This.one and This.two are custom properties of the ActiveDoc class. The Run event code below is expecting two parameters, separated by a plus sign.

Sample Code
-----------


   PROCEDURE Init
      PARAMETERS one,two
      This.one=one
      This.two=two
   ENDPROC

   PROCEDURE Run
      LPARAMETERS cHyperLinkTarget
      IF ISHOSTED() THEN
         MyHost=GETHOST()
         IF MyHost.Name='Microsoft Internet Explorer' THEN
            This.one= ;
               SUBSTR(cHyperLinkTarget,2,AT('+',cHyperLinktarget)-2)
            This.two=SUBSTR(cHyperLinkTarget,AT('+',chyperlinktarget)+1)
         ENDIF
      ENDIF
      DO FORM test1 WITH This.one,This.two
      READ EVENTS
      ENDPROC

REFERENCES

Visual FoxPro "Programmer's Guide," 6.0, Chapter 31 - Interoperability and the Internet Visual FoxPro Help, version 6.0, search on: "ISHOSTED()"; "GETHOST()"

Additional query words: kbvfp600

Keywords :
Version : WINDOWS:6.0
Platform : WINDOWS
Issue type : kbhowto