This chapter is from the book
This chapter is from the book
This chapter is from the book
Example: Scripting Internet Explorer
To give you a taste of the power and flexibility of scripting—particularly Automation programming—I'll close this chapter by showing you how to program a specific Automation server: Internet Explorer. You'll see that your scripts can control just about everything associated with Internet Explorer:
- The position and dimensions of the window
- Whether the menu bar, toolbar, and status bar are displayed
- The current URL
- Sending the browser backward and forward between navigated URLs
Displaying a Web Page
To get started, I'll show you how to use the InternetExplorer object to display a specified URL. You use the Navigate method to do this, and this method uses the following syntax:
InternetExplorer.Navigate URL [, Flags,] [ TargetFramename] [, PostData] [ ,Headers]
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InternetExplorer |
A reference to the InternetExplorer object with which you're working. |
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URL |
The address of the web page you want to display. |
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Flags |
One of (or the sum of two or more of) the following integers that control various aspects of the navigation: |
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1 Opens the URL in a new window |
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2 Prevents the URL from being added to the history list |
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4 Prevents the browser from reading the page from the disk cache |
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8 Prevents the URL from being added to the disk cache |
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TargetFrameName |
The name of the frame in which to display the URL. |
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PostData |
Specifies additional POST information that HTTP requires to resolve the hyperlink. The most common uses for this argument are to send a web server the contents of a form, the coordinates of an imagemap, or a search parameter for an ASP file. If you leave this argument blank, this method issues a GET call. |
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Headers |
Specifies header data for the HTTP header. |
Here's an example:
Set objIE = CreateObject("InternetExplorer.Application")
objIE.Navigate "http://www.microsoft.com/"
Navigating Pages
Displaying a specified web page isn't the only thing the InternetExplorer object can do. It also has quite a few methods that give you the ability to navigate backward and forward through visited web pages, refresh the current page, stop the current download, and more. Here's a summary of these methods:
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GoBack |
Navigates backward to a previously visited page |
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GoForward |
Navigates forward to a previously visited page |
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GoHome |
Navigates to Internet Explorer's default Home page |
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GoSearch |
Navigates to Internet Explorer's default Search page |
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Refresh |
Refreshes the current page |
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Refresh2 |
Refreshes the current page using the following syntax:Refresh2(Level) |
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Level |
A constant that determines how the page is refreshed: |
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0 |
Refreshes the page with a cached copy |
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1 |
Refreshes the page with a cached copy only if the page has expired |
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3 |
Performs a full refresh (doesn't use a cached copy) |
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Stop |
Cancels the current download or shuts down dynamic page objects, such as background sounds and animations. |
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Using the InternetExplorer Object's Properties
Here's a summary of many of the properties associated with the InternetExplorer object:
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Busy |
Returns True if the InternetExplorer object is in the process of downloading text or graphics. This property returns False when a download of the complete document has finished. |
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FullScreen |
A Boolean value that toggles Internet Explorer between the normal window and a full-screen window in which the title bar, menu bar, toolbar, and status bar are hidden. |
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Height |
Returns or sets the window height. |
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Left |
Returns or sets the position of the left edge of the window. |
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LocationName |
Returns the title of the current document. |
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LocationURL |
Returns the URL of the current document. |
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MenuBar |
A Boolean value that toggles the menu bar on and off. |
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StatusBar |
A Boolean value that toggles the status bar on and off. |
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StatusText |
Returns or sets the status bar text. |
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ToolBar |
A Boolean value that toggles the toolbar on and off. |
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Top |
Returns or sets the position of the top edge of the window. |
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Type |
Returns the type of document currently loaded in the browser. |
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Visible |
A Boolean value that toggles the object between hidden and visible. |
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Width |
Returns or sets the window width. |
Running Through a Sample Script
To put some of the properties and methods into practice, Listing 12.10 shows a sample script.
Listing 12.10. A Script That Puts the InternetExplorer Object Through Its Paces
Option Explicit
Dim objIE, objWshShell, strMessage, intResult
' Set up the Automation objects
Set objIE = WScript.CreateObject("InternetExplorer.Application")
Set objWshShell = WScript.CreateObject("WScript.Shell")
' Navigate to a page and customize the browser window
objIE.Navigate "http://www.wordspy.com/"
objIE.Toolbar = False
objIE.StatusBar = False
objIE.MenuBar = False
' Twiddle thumbs while the page loads
Do While objIE.Busy
Loop
' Get the page info
strMessage = "Current URL: " & objIE.LocationURL & vbCrLf & _
"Current Title: " & objIE.LocationName & vbCrLf & _
"Document Type: " & objIE.Type & vbCrLf & vbCrLf & _
"Would you like to view this document?"
' Display the info
intResult = objWshShell.Popup(strMessage, , "Scripting IE", vbYesNo + vbQuestion)
' Check the result
If intResult = vbYes Then
' If Yes, make browser visible
objIE.Visible = True
Else
' If no, bail out
objIE.Quit
End If
Set objIE = Nothing
Set objWshShell = Nothing
The script begins by creating instances of the InternetExplorer and WScript Shell objects. The Navigate method displays a page, and then turns off the toolbar, status bar, and menu bar. A Do...Loop checks the Busy property and loops while it's True. In other words, this loop won't exit until the page is fully loaded. A string variable is used to store the URL, the title, and type of the page, and this string is then displayed in a Popup box, which also asks whether the user wants to see the page. If the user clicks the Yes button, the browser is made visible; if the user clicks the No button, the Quit method shuts down the browser.