Using FileMaker as a Web Services Source

So far in this chapter, we've mainly discussed how to get data from Web services, into FileMaker. But it's possible to do this the other way around as well. Let's say that you have some order data in FileMaker Pro. Let's also suppose that there's a central mainframe computer that needs to have access to the FileMaker orders, as they're completed.

There are a number of ways to skin this particular cat, but let's suppose for the sake of example that the mainframe system is capable of requesting data from a Web service. In other words, the mainframe can make a request for data over HTTP, and expects to get some form of XML back in return.

The strategy for handling this with FileMaker is straightforward. First, you need to make the relevant FileMaker database available over the Web. This means you need to have a copy of FileMaker Server with the appropriate Web publishing technologies enabled, and you need to have the particular database in question available for Web access.

For more information on configuring Web publishing on your FileMaker Server, see "Configuring FileMaker Server 7 Advanced for IWP," p. 613 , as well as "Setting up the Server-side Components for CWP," p. 676 .

Assuming your FileMaker databases are correctly configured for Web access, the procedure for allowing FileMaker to act as a Web services server is relatively straightforward. All that's necessary is to make potential Web services clients aware of the correct URLs to use. You'll provide one or more URLs that will publish FileMaker data to an XML format. You could provide a URL that would provide "raw" XML in one of FileMaker's built-in XML grammars. For example:

 http://192.168.123.101/fmi/xml/fmresultset.xml?-db=products-lay=sales&-findall 

Or you could provide a URL that would first format the outbound XML with a stylesheet, like this:

 http://192.168.123.101/fmi/xsl/my_template/my_stylesheet  .xsl?-grammar=fmresultset&-db=mydatabase &-lay=mylayout&-findall 

As you'll learn in Chapter 23, "Custom Web Publishing," it's possible to include access validation logic in your stylesheets that could (for example) check to make sure that Web services requests came from only a select set of IP addresses, or perform some other kind of validation.

In general, though, using FileMaker as a Web services provider falls under the heading of Custom Web Publishing, which we cover thoroughly in Chapter 23.