HomeOracle Page 2 - Data Manipulation and More for HTML DB Applications
Manually Creating a Web Services Process - Oracle
In this conclusion to a three-part series covering the addition of validations, computations, and processes to an HTML DB application, you will learn about data manipulation, manually creating a web services process, and more. This article is excerpted from chapter 13 of the Oracle HTML DB Handbook, written by Lawrence Linnemeyer and Bradley Brown (McGraw-Hill, 2006; ISBN: 0072257687).
To create a Web Services process manually, after starting the Create Page Process Wizard, select the Web Services type. In the next step of the wizard, you will supply a name and a sequence. You can accept the defaults for the Type field and the Point field, which will be On Submit – After Computations and Validations.
Many web services offer different operations from the same Web Service Reference. For instance, a ZIP code web service may offer an operation to return the city for a ZIP code, an operation to return the city and state, or an operation to return the distance between two ZIP codes. In the next step of the wizard, you will select the Web Service Reference from an LOV and then a particular operation from an LOV, which will be based on the reference you selected.
When you select a particular operation, the wizard will provide two additional sections—one for the input parameters and one for the output parameters, as shown next. The source for the input parameter can be either a static value or an item on your page. Some web services are subscription services and you must provide a username and a password. For these, you use a static value that your users never see. For the remaining items—the ones you want your users to be able to enter values for—you will want to use page items. In the Value field, you either enter the static value or the name of the page item.
For the output parameters, you need to specify whether to use items or collections. Items are used for web services that return a single record. Collections are used for a web service that returns multiple records in the results. The two final steps in the wizard for a Web Services process allow you to enter success and failure messages and any conditions under which you want the process to be evaluated.