The XML-RPC server of the online service receives the XML encoded procedure call and decodes it
into a format that the system code can process, e.g. $store->getPriceForItem(123).
7. The system code returns the requested price to its XML-RPC server which encodes that as an XML
response and sends it back to the requesting desktop application:
19.95
8. The desktop application receives the response and decodes it into a format it can process and updates
the price for item 123 to $19.95.
11.1.4 Why do we need web services?
The simple answer to this question is also the most ironic; we need web services so that applications running
on different platforms and/or frameworks can talk to each other in standard way. This chapter has already
Licensed to Menshu You
Zend Framework in Action (Ch01) Manning Publications Co. 18
started to point out the irony in that concept by, in all likelihood, confusing you with what is only a small
selection of the variations in the protocols that make up these ???standards???.
Pushing this cynicism aside however and returning to the example of our desktop application fetching
updated prices from the online service, you??™ll notice that there was little detail about how each end of the
transaction actually performed their procedure calls and the reason was that it didn??™t matter.
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