Overview of Web Technologies

Access developers can readily build Web solutions with data access pages and Office Web Components . These two technologies assist you in creating Web solutions that share data with many users, but both have characteristics that make it better suited for particular scenarios. This section provides brief summaries of these technologies to help you evaluate which tools best meet the needs of your clients .

When building Web solutions with either of the technologies just mentioned, you will typically deploy files to a Web site where others can access them. FrontPage is a Web site management tool that ships with Office. It has a look and feel that resembles other Office components. Therefore, FrontPage enables Office users to readily contribute content to a Web site and developers with limited Web experience can serve as Web site administrators.

Data Access Pages

A data access page is a Web page with special ties to Access 2003. It makes available graphical tools for building Web solutions that resemble Access forms and reports. A Web solution can consist of one or more data access pages, or it can contain a mix of data access pages, other kinds of Web pages, and additional files, such as those with graphic images. In addition, you can publish some Access reports and forms as data access pages. This makes it possible to build a form or report in Access and then publish it as a data access page. Access also offers a programming environment that complements and extends the graphical development tools that make data access pages so easy to create solutions with.

You need to understand that, unlike Access forms and reports residing within Access database files and Access projects, a data access page is a standalone file. The Access Database window shows a Pages collection just like the Forms and Reports collections. However, the items in the Database window representing pages are links that point at external files.

Like forms, data access pages have two key views. Page view shows the data, if any, on the page. For example, if a page represents a form tied to a table, you can use the form to navigate the table records. You can also open a data access page in a browser by pointing the browser at the URL of the standalone file for the data access page. Design view reveals the objects within a data access page. These objects are controls, many of which are similar to those for forms, and other design objects for the data access page, such as a navigation bar. However, some of these controls are especially tailored for the Web environment. Both the Page view and Design view are available directly from the Database window. Just select the page name in the Database window, and click Open for the Page view or Design for the Design view. A third view, named Web Page Preview, is available from either of the first two views. Selecting this third view opens a browser session as a container for the data access page. This view shows a Web page designer exactly how the page looks in a browser. You can access the Web Page Preview from the standard View control on the toolbar.

The data access page format is different in Access 2000, Access 2002, and Access 2003. Therefore, you must upgrade the Access version on workstations if you want to open data access pages created with Access 2003 in Page view. You must install Office Web Components for Office 2003 if you want to view data access pages created with Access 2003 from Access 2000 or Access 2002 workstations. However, this upgrade does not permit you to open Access 2002 data access pages in Design view on a workstation running either Access 2000 or Access 2003. To gain that functionality, you must install Access 2003 as a part of Office 2003. You can have Access 2003 running simultaneously with Access 2000 and Access 2002 on the same workstation. These same version compatibility guidelines apply to Office Web Components discussed in the next section.

Note  

Office 2000, Office 2002, and Office 2003 can run side by side on a single computer, therefore, there is no need to upgrade solutions that work in a prior Office version so long as you have that version on a computer.

Office Web Components

There are four Office Web Components: the Data Source Control object, the Chart control, the PivotTable list control, and the Spreadsheet control. The Data Source Control object is the data engine behind data access pages. A separate ActiveX control implements each of the Office Web Components. You can use these components in isolation on Web pages or in combination. For example, one Web page can use the Data Source Control object to include a form based on data in a table. You can also use the Spreadsheet control to build a spreadsheet on the Web page that can create projections based on the data that displays in the form. And you can use the Chart control to create a chart on the page that can graph the projections in the spreadsheet.

The PivotTable list control mainly targets solutions for business decision analysts. Many business analysts are already familiar with PivotTable reports from Microsoft Excel. The PivotTable list control enables developers to publish subsets of data from a database. Developers can enable end users to manipulate the data from browsers by publishing subsets of it on Web pages containing PivotTable list controls. By publishing the data in a PivotTable, developers save end users from having to write queries whenever they want to process data. Developers can also precisely specify the scope of data to which end users have access by restricting the record sources that contribute to a PivotTable list. In addition to supporting security, this capability can improve performance by avoiding poorly constructed and overly broad queries.

Office Web Components is distributed through the installation of Office XP. Two .dll files, MSOWCW.DLL and OCW11.DLL, implement the components. You can get programming help for Office Web Components from OWCVBA11.CHM, which is installed by default in the local resources folder at C:\Program Files\Common Files\Microsoft Shared\Web Components\11\. On my computer, the local resources folder is 1033.

Active Server Pages

Active Server Pages (ASP) is a Microsoft Internet Information Services (IIS) technology that lets you script pages on a server for client browsers. ASP files are popularly used to present dynamic Web pages, including those that reflect ongoing data updates. You can also use ASP files to process forms in a Web environment.

Though data access pages offer a rich graphical environment through Access, ASP files aren't considered a strong graphical development tool. You can populate ASP files with HTML and a scripting language, such as Microsoft Visual Basic Scripting Edition (VBScript). The script and HTML run on the Web server to create a file for the server to send to a browser. The page for the browser doesn't contain any server-side script and can include pure HTML. The client environment is one of the main distinctions between data access pages and ASP files. Because ASP files can write pure HTML, their output can be appropriate for any browser that reads HTML ( essentially all browsers). By contrast, data access pages work exclusively in Microsoft Internet Explorer 5 or later.

ASP development can be code intensive and unfamiliar to Access developers. In addition, the availability of ASP.NET, a .NET Framework alternative to traditional ASP Web pages, suggests that traditional ASP development might be coming to an end. If you know ASP already, you can use it, so long as you can live without the benefits of ASP.NET. For those who care to learn more about integrating ASP with Access database files, a chapter on the topic can be found at http://www.programmingmsaccess.com/ForA2002/Ch17A2002.