Developing Applications for theInternet and the World Wide Web

Microsoft Access applies the following rules when it interprets the progression of tags and tag pairs within the HTML table it imports or links:

• The <TD> tag pair may be closed with either a </TD> tag or a </TH> tag.
• The <TH> tag pair may be closed with either a </TH> tag or a </TD> tag.
• The <TR> tag is not required to start a new row. If a <TD> tag follows a </TR> tag, Microsoft Access assumes this is the beginning of a new row.
• If a </TABLE> tag is not preceded by a </TR> tag, then Microsoft Access assumes this is the end of the row.

In many cases, a table cell can display something other than text. If a table cell contains an embedded graphic file, there is a <IMG SRC...> tag associated with it. This tag may or may not have additional text that would be displayed. If additional text is present, Microsoft Access imports it, but Microsoft Access doesn’t import the embedded graphic and the tag that defines it. However, this is not true of embedded anchor <A HREF> tags; Microsoft Access imports anchor tags as Hyperlink fields.

HTML tables can contain lists that are embedded within a table cell. Lists in an HTML table cell are formatted with the <LI> and </LI> tags. Microsoft Access inserts a carriage return and line feed (<CR><LF>) after each list item and imports each item in the list as a separate field for that record.

HTML tables can also contain tables that are embedded within a table cell. You can import these as separate tables.

To achieve the most predictable results, import simple HTML tables with a fixed number of fields per record, without embedded lists or tables.

Exporting, Importing, and Linking Data fromOther Data Sources on Internet Servers

You can export any Microsoft Access-compatible external data file to an FTP server. You can’t export files to HTTP servers through the Internet, because you can’t write to them using the HTTP protocol.

Û To export data from external data sources on Internet servers

1. On the File menu, click Save As/Export.
2. In the Save As dialog box, click To An External File Or Database, and then click OK.
3. In the Save As Type box, select the type of file you want to export.
4. Specify an FTP server by using any of the following methods:
   • In the File Name box, type a valid ftp:// URL.
   • In the Save In box, click Internet Locations (FTP) and select a previously defined FTP site.
   • In the Save In box, click Add/Modify FTP Locations, then specify a new FTP site and browse its files.
5. Click Export.

You can also import and link any Microsoft Access-compatible external data file, except Microsoft Access databases and ODBC data sources, by using an FTP or HTTP connection. An FTP or HTTP connection is only maintained long enough to perform a single transaction. Therefore, when you import or link a file located on an FTP or HTTP server, Microsoft Access copies the data file to the user’s local cache. Microsoft Access then imports or links to the data file in the local cache. For this reason, files linked with an FTP or HTTP connection are read-only.

Û To import or link data from external data sources on Internet servers

1. On the File menu, point to Get External Data, and then click either Import or Link Tables.
2. In the Files Of Type list, select the type of file you want to import or link.
3. To specify an FTP server, use any of the following methods:
   • In the File Name box, type a valid ftp:// URL.
   • In the Look In box, click Internet Locations (FTP) and select a previously defined FTP site.
   • In the Look In box, click Add/Modify FTP Locations, then specify a new FTP site and browse its files.

   To specify an HTTP server:

   • In the File Name box, type a valid http:// URL.
4. Click Import or Link.

Using the WebBrowser Control

The Microsoft WebBrowser control is an ActiveX control that you can use on your application’s forms to browse Web sites, view Web pages and other documents, and download data located on the Internet. The WebBrowser control is useful in situations where you don’t want to disrupt the work flow in your application by switching from Microsoft Access to a Web browser or other document-viewing application.

The WebBrowser control can display any Web page that Microsoft Internet Explorer version 3.0 can display. For example, the WebBrowser control can display pages that include any of the following features:

• Standard HTML and HTML enhancements, such as floating frames and cascading style sheets
• Other ActiveX controls
• Most Netscape plug-ins
• Scripting, such as Microsoft Visual Basic Scripting Edition (VBScript) or JavaScript
• Java™ applets
• Multimedia content, such as video and audio playback
• Three-dimensional virtual worlds created with Virtual Reality Modeling Language (VRML)

In addition to opening Web pages, the WebBrowser control can open any ActiveX document, which includes most Microsoft Office documents. For example, if Microsoft Office is installed on a user’s computer, an application that uses the WebBrowser control can open and edit Microsoft Excel spreadsheets, Microsoft Word documents, and Microsoft PowerPoint presentations from within the control. Similarly, if Microsoft Excel Viewer, Microsoft Word Viewer, or Microsoft PowerPoint Viewer is installed, users can view those documents within the WebBrowser control.

With the WebBrowser control, users of your application can browse sites on the World Wide Web, as well as folders on a local hard disk and on a local area network. Users can follow hyperlinks by clicking them or by typing a URL into a text box. Also, the WebBrowser control maintains a history list that users can browse through to view previously browsed sites, folders, and documents.

Note   Additional ActiveX controls that you can use to work with content on the Internet or an intranet are available in Microsoft Office 97, Developer Edition.

Adding the WebBrowser Control to a Form

Before you can add the WebBrowser control to a form, you must have Microsoft Internet Explorer version 3.0 or later installed.

If you purchased Microsoft Office 97 on CD-ROM, you can install Microsoft Internet Explorer version 3.01 by running Msie301.exe from the Iexplore subfolder in the ValuPack folder.

If you purchased Microsoft Access 97 on floppy disks, or if you prefer to install from the Web, you can download and install the latest version of Microsoft Internet Explorer from http://www.microsoft.com/ie/download/.

Once you have Microsoft Internet Explorer version 3.01 installed, the WebBrowser control is automatically registered and is available in form Design view.

Û To add the WebBrowser control to a form

1. Open the form in Design view.

   

2. In the toolbox, click the More Controls tool.

   A menu appears that lists all the registered ActiveX controls in your system.

3. On the menu of ActiveX controls, click Microsoft WebBrowser Control.
4. On the form, click where you want to place the control.
5. Move and size the control to the area you want to display.

   

Tip   If the WebBrowser control can’t display the full width or height of a Web page or document, it automatically displays scroll bars. However, in most cases, you should make the control wide enough to display the full width of a typical Web page so that users of your application don’t have to scroll horizontally.

Note   After you add a WebBrowser control to a form and save the form or display it in Form view, the control retains its original size even when you re-open the form in Design view and resize the control. To resize the control, delete the existing control, add a new control, and then resize the new control and set its properties before saving the form.

Displaying Web Pages or Documents in the WebBrowser Control

To display a Web page or document in the WebBrowser control, use the Navigate method in Visual Basic. The syntax for the Navigate method is:

object.Navigate URL

Object is either the name of the WebBrowser control on your form or an object variable that refers to it, and URL is a string expression that evaluates to a valid URL or path. URL can refer to a Web page or other content on the Internet or an intranet, as well as to an Office document, such as a Microsoft Word document.

If URL refers to an Internet protocol and a location on the Internet, Microsoft Access must establish a connection before is can display the document. If the computer running your application is connected to a proxy server (a secure connection to the Internet through a LAN), or if it has a direct connection to the Internet, the WebBrowser control downloads and displays the Web page or other Internet content immediately. If the computer running your application uses a modem and dial-up connection to the Internet, and that connection hasn’t been established beforehand, the WebBrowser control initiates the connection. For example, if the user’s computer uses a modem and The Microsoft Network to connect to the Internet, the Sign In dialog box is displayed to establish the connection to the Internet before the WebBrowser control can display Internet content.

If URL refers to an Internet protocol and a location on an intranet server, the computer running your application must be connected to the intranet and have permission to access that server.

If URL refers to a standard file system path on a local hard drive or intranet, the WebBrowser control opens the document and displays it immediately. The WebBrowser control can open Microsoft Office documents, text files, and HTML documents that don’t require features supported only by an Internet server. For example, the WebBrowser control can’t open HTML documents that use IDC/HTX files or Active Server Pages (ASP) files from the standard file system, but it can open HTML documents that contain only the HTML tags supported by Microsoft Internet Explorer version 3.0.

Note   If URL refers to a path in the standard file system that doesn’t refer to a file name (for example, C:\Windows\System\), the WebBrowser control displays the file system itself, much like My Computer.

Displaying a Document in the WebBrowser Control by Using an Address in a Text Box

Using the WebBrowser control, you can create a form that performs most of the functions of Microsoft Internet Explorer version 3.0. For example, the following illustration shows the Custom Browse form (WebBrowseWeb) in the Developer Solutions sample application.

When a user types a valid URL in the text box at the top of the form (txtLinks) and presses ENTER, the WebBrowser control (ActiveXCtl1) displays the Web page or document. Pressing ENTER triggers the AfterUpdate event of the txtLinks text box; the AfterUpdate event contains the following code which navigates to the URL entered by the user:

Private Sub txtLinks_AfterUpdate()
On Error Resume Next
	If Len(Me!txtLinks) > 0 Then
		Me!ActiveXCtl1.Navigate Me!txtLinks
	End If
End Sub

Error handling is passed to the control itself because it displays the same error messages displayed by Microsoft Internet Explorer version 3.0.

If you prefer to start navigation by clicking a command button instead pressing ENTER, you can use similar code in the button’s Click event.

The Home, Back, Forward, Refresh, and Search buttons on the Custom Browse form use the corresponding GoHome, GoBack, GoForward, Refresh, and GoSearch methods of the WebBrowser control.

See Also   For information on how to view brief descriptions about the properties, methods, and events of the WebBrowser control, see “Viewing Descriptions of the Properties, Methods, and Events of the WebBrowser Control” later in this chapter.

With the Save Location button on the Custom Browse form, you can save the address and a description of the current document to the Links table in the Developer Solutions database. When you click the Save Location button, Microsoft Access checks to see if the URL has been saved previously, and if not, uses the following statement to open the Save Location To Table dialog box:

DoCmd.OpenForm "frmSaveURLDialog", acWindowNormal, , , acFormEdit, acDialog, _	ctlHyper.LocationName & ";" & ctlHyper.LocationURL

The last argument of this statement (ctlHyper.LocationName & ";" & ctlHyper.LocationURL) sets the OpenArgs property to a concatenated string that contains the two values returned by the LocationName and LocationURL properties of the document currently displayed in the Custom Browse form. When the Save Location To Table dialog box opens, code in its Load event parses the OpenArgs property value back into two parts and displays them as the default description and address. When the user clicks OK, the description and address in the Save Location To Table dialog box form are saved in the Hyperlink and Description fields in the Links table.

See Also   For more information on the Custom Browse form, open the Developer Solutions sample application located in the Samples subfolder of your Office folder.

Displaying a Document in the WebBrowser Control by Using a Hyperlink Stored in a Table

Using the WebBrowser control, you can create a form that displays documents specified in hyperlinks stored in a table. For example, the following illustration shows the Browse Saved Hyperlinks (WebBrowseTable) form in the Developer Solutions sample application. You can use the Browse Saved Hyperlinks form to browse addresses saved in the Links table.

When a user clicks a record navigation button at the bottom of the form to move to a new record, the following code in the form’s Current event displays the Web page or document whose address is stored in the current record.

Private Sub Form_Current()
	Dim varFull As Variant, varDescription As Variant
	Dim HyperlinkAddress As String, HyperlinkSubAddress As String
	Dim msg1 As String, msg2 As String, rst As Recordset, strDisplay As String
	
	On Error Resume Next

	Set rst = Me.RecordsetClone
	rst.Bookmark = Me.Bookmark
	varFull = rst!HyperLink

	If IsNull(varFull) Then GoTo Current_Err
	varDescription = rst!Description
	Me!ActiveXCtl1.Navigate HyperlinkPart(varFull, acAddress)

	If Err = 438 Then Exit Sub

	gvarBookMark = Me.Bookmark

Current_Bye:
	Exit Sub
Current_Err:

msg1 = "Invalid hyperlink address. Remove the record described as '"
msg2 = "' from the Links table or edit the hyperlink to supply a valid address."

MsgBox msg1 & rst!Description & msg2
	
		Me.Bookmark = gvarBookMark
		Exit Sub
End Sub

This procedure uses the Navigate method of the WebBrowser control to display the next hyperlink address. However, don’t pass the contents of a Hyperlink field directly to the Navigate method. If a user enters or edits data stored in a Hyperlink field from a datasheet or form, it may contain up to three parts of information separated by the number sign (#). Even if the user doesn’t enter all three parts in the datasheet or form, Microsoft Access automatically stores number signs in the field. If there are number signs in the Hyperlink field, passing the data from the field directly to the Navigate method generates an error. To handle this, the stored value is passed to the HyperlinkPart function to extract the address portion of the saved hyperlink, which is then passed to the Navigate method. If navigation is successful, the form’s Bookmark property value is stored in a public variable. This public variable is used to return to the last record if subsequent navigation fails.

Using code to save data in a Hyperlink field doesn’t automatically save number signs in the field. To preserve the proper functioning of a Hyperlink field in other contexts, you may want to write your code to save number signs before and after a hyperlink address. For an example of how to do this, see the event procedure set for the Click event of the Save Location button (cmdSaveLocation) on the Custom Browse form.

Note   You don’t have to store addresses in a Hyperlink field if you don’t need users to be able to navigate to addresses by clicking them in datasheets or forms, or if you don’t need to save addresses as HTML anchor tags when saving as HTML. As long as an address doesn’t exceed 255 characters, you can store it in a Text field. If an address exceeds 255 characters, you can store it in a Memo field. In either case, you can pass the value stored in the field directly to the Navigate method.

See Also   For more information on the Browse Saved Hyperlinks form, open the Developer Solutions sample application located in the Samples subfolder of your Office folder. For more information on the format of data stored in a Hyperlink field, see “The Hyperlink Field Storage Format” earlier in this chapter.

Viewing Descriptions of the Properties, Methods, and Events of the WebBrowser Control

Like built-in Microsoft Access objects, the WebBrowser control has properties that your application can set or read to determine the control’s characteristics, methods that your application can use to perform operations on the control, and events your application can respond to. You can view brief descriptions of the properties, methods, and events of the WebBrowser control by using the Object Browser.

Important In order for these properties, methods, and events to appear in the Object Browser, you must set a reference to the Microsoft Internet Controls object library. To set this reference, open a module, click References on the Tools menu, and select the Microsoft Internet Controls check box in the Available References box.

Û To view descriptions of the WebBrowser control’s methods, properties, and events

1. Open a module.
2. On the View menu, click Object Browser.
3. In the Project/Library box, click SHDocVw.
4. In the Classes box, click WebBrowser.

   The Members Of box lists the methods, properties, and events associated with the WebBrowser control.

See Also    If you purchased Microsoft Access 97 on CD-ROM, you can view a Help file that contains this information by opening the \ValuPack\Access\Webhelp folder on the Setup CD-ROM, and then copying the Iexplore.hlp and Iexplore.cnt files to your hard disk.

Distributing the WebBrowser Control with Your Application

Unlike most other ActiveX controls, you can’t install the WebBrowser control by itself. For an application that uses the WebBrowser control to work, Microsoft Internet Explorer version 3.0 must also be installed on the computer. Microsoft Internet Explorer version 3.0 can be distributed freely, and doesn’t require the payment of royalties or other licensing fees.

See Also   For information on installing Microsoft Internet Explorer version 3.0, see “Adding the WebBrowser Control to a Form” earlier in this chapter.

Setting Up a Personal Web Server

Microsoft provides two products that make it easy to create a personal Web server on your computer for low-volume Web publishing: Microsoft Personal Web Server and Microsoft Peer Web Services. These products are ideal for publishing departmental home pages, personal home pages, or small-scale Web applications on your company’s intranet.

Although Personal Web Server and Peer Web Services are intended for small-scale Web publishing, they provide most of the same services and features as Microsoft Internet Information Server, a robust Web server intended for high-volume Web publishing. You can use Personal Web Server or Peer Web Services to develop and test your Web applications, and then transfer them to a Web server running Microsoft Internet Information Server.

Both Personal Web Server and Peer Web Services can:

• Publish Web pages on the Internet or over a LAN on an intranet by using the HTTP service.
• Support Microsoft ActiveX controls.
• Transmit or receive files by using the FTP service.
• Run Internet Server API (ISAPI) and Common Gateway Interface (CGI) scripts.
• Send queries to ODBC data sources by using the Internet Database Connector component (Httpodbc.dll).
• Support the Secure Sockets Layer.

In addition, Peer Web Services can:

• Use pass-through security to Windows NT Server and Novell NetWare.
• Use local-user security if Microsoft File and Print Sharing are not installed.
• Perform remote administration by using a Web-based application.
• Distribute documents by using the Gopher service.

Installation Requirements

To run Personal Web Server or Peer Web Services, you must meet the following installation requirements.

Personal Web Server

• A computer with Windows 95 installed.
• A CD-ROM drive for the installation compact disc.
• Adequate disk space for your information content.

Peer Web Services

• A computer with Windows NT Workstation version 4.0 installed.
• A CD-ROM drive for the installation compact disc.
• Adequate disk space for your information content. It is recommended that all drives used with Peer Web Services be formatted with the Windows NT File System (NTFS).

Publication Requirements

When using Personal Web Server or Peer Web Services, each computer you want to access the server must have Transmission Control Protocol/Internet Protocol (TCP/IP) installed. The TCP/IP protocol is included with Windows 95 and Windows NT Workstation version 4.0. To install and configure the TCP/IP protocol and related components, double-click the Network icon in Control Panel. Each system must meet additional requirements depending on whether you want to use the server on an intranet or the Internet.

Intranet Publication Requirements

• A network adapter card and local area network (LAN) connection.
• The Windows Internet Name Service (WINS) server or the Domain Name System (DNS) server installed on a computer in your intranet. WINS and DNS run only on Windows NT Server. This step is optional, but it does allow users to use “friendly names” instead of IP addresses when connecting to your server.

Internet Publication Requirements

• An Internet connection and Internet Protocol (IP) address from your Internet Service Provider (ISP).
• DNS registration for that IP address. This step is optional, but it does allow users to use “friendly names” instead of IP addresses when connecting to your server. For example, “microsoft.com” is the friendly domain name registered to Microsoft. Within the microsoft.com domain, Microsoft has named its World Wide Web (WWW) server “www.microsoft.com.” Most ISPs can register your domain names for you.
• A network adapter card suitable for your connection to the Internet.

Installing Personal Web Server

The Setup file for the Personal Web Server is available on the Web. To download the Setup program for Personal Web Server for Windows 95, connect to the Microsoft Personal Web Server home page at:

http://www.microsoft.com/ie/iesk/pws.htm

You can install Personal Web Server if you are running Windows 95 or Windows NT Workstation version 4.0. However, if you are using Windows NT, it is recommended that you install Peer Web Services instead.

Û To install Personal Web Server

1. Connect to the Personal Web Server home page on the Web and download PWS10a.exe.
2. Double-click PWS10a.exe.

   This starts the installation process. You may be required to supply additional files from your Windows 95 Setup disks.

3. When installation is finished, the Setup program asks if you want to restart your computer. Click Yes.

Installing Peer Web Services

The files to install Peer Web Services are provided on the Microsoft Windows NT Workstation version 4.0 Setup CD-ROM.

Û To install Peer Web Services

1. Click the Windows Start button, point to Settings, and click Control Panel.
2. Double-click Network.
3. Click the Services tab, and then click Add.
4. In the Network Service list, double-click Peer Web Services.

   This starts the installation process. You may be required to supply additional files from your Windows NT Setup disks.

5. In the first Microsoft Peer Web Services Setup dialog box, click OK.
6. In the second Microsoft Peer Web Services Setup dialog box, select which services you want to install, and then click OK.
7. In the Publishing Directories dialog box, specify the directories you want to use for each service, or accept the default directories, and then click OK.

Getting More Information

For more information about Using Personal Web Server or Peer Web Services, you can refer to their online documentation, which is available once installation is complete.

Û To view documentation for Personal Web Server or Peer Web Services

1. Start your Web browser.
2. To view the documentation for Personal Web Server, in your browser’s address box, type:

   http://MyServer/docs/default.htm

   To view the documentation for Peer Web Services, in your browser’s address box, type:

   http://MyServer/iisadmin/htmldocs/inetdocs.htm

   where MyServer is the name of the computer on which you installed Personal Web Server or Peer Web Services. To determine the name of the computer, open Control Panel, double-click the Network icon, and then click the Identification tab.

3. Press ENTER.

Using Active Server Pages with Personal Web Server or Peer Web Services

If you want to use Active Server Pages with either Personal Web Server or Peer Web Services, you must install the Active Server Pages components after installing your server software. These components are not distributed with the Setup programs for Personal Web Server or Peer Web Services. To download the Setup program for these components, connect to http://www.microsoft.com/msdownload/iis_asp.htm.

Note   To install the Active Server Pages components for Personal Web Server running on Windows 95, download the Active Server Pages for Windows NT (i386) Setup files.

See Also   For more information on the Internet Information Server version 3.0 and the Active Server Pages components, connect to http://www.microsoft.com/iis/default.asp.