Monday, April 27, 2009

Building an InternetExpress application

The following steps describe how to build a Web application that creates HTML pages for allowing users to interact with the data from an application server via a javascript-enabled Web browser.
1.Choose File|New to display the New Items dialog box, and on the New page select Web Server application.

2.From the MIDAS page of the component palette, add a connection component to the Web Module that appears when you create a new Web server application. The type of connection component you add depends on the communication protocol you want to use.

3.Set properties on your connection component to specify the application server with which it should establish a connection.

4.Instead of a client dataset, add an XML broker from the InternetExpress page of the component palette to the Web module. Like TClientDataSet, TXMLBroker represents the data from a provider on the application server and interacts with the application server through its IAppServer interface. However, unlike client datasets, XML brokers request data packets as XML instead of as OleVariants and interact with InternetExpress components instead of data controls.

5.Set the RemoteServer property of the XML broker to point to the connection component you added in step 2. Set the ProviderName property to indicate the provider on the application server that provides data and applies updates.

6.Add a MIDAS page producer to the Web module for each separate page that users will see in their browsers. For each MIDAS page producer, you must set the IncludePathURL property to indicate where it can find the javascript libraries that augment its generated HTML controls with data management capabilities.

7.Right-click a Web page and choose Action Editor to display the Action editor. Add action items for every message you want to handle from browsers. Associate the page producers you added in step 6 with these actions by setting their Producer property or writing code in an OnAction event handler.

8.Double-click each Web page to display the Web Page editor. (You can also display this editor by clicking the ellipsis button in the Object Inspector next to the WebPageItems property.) In this editor you can add Web Items to design the pages that users see in their browsers.

9.Build your Web application. Once you install this application with your Web server, browsers can call it by specifying the name of the application as the scriptname portion of the URL and the name of the Web Page component as the pathinfo portion.

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