Microsoft SharePoint 2007 Technologies

608 18.8 Adding Code to a Form Template

18.8 Adding Code to a Form Template

InfoPath 2007 provides integration capabilities with Visual Studio to allow

you to write managed code for your browser-enabled form templates. Visual

Studio 2005 is the primary development environment when it comes to

extending the SharePoint functionality; therefore, it makes sense that this

becomes the standard development environment for adding code to InfoPath

form templates. Visual Studio Tools for Applications (VSTA) is tightly inte-

grated with InfoPath and allows you to add code to your form within the

confines of the InfoPath client. VSTA is installed as an optional component

as part of the InfoPath 2007 client installation. If you already have InfoPath

2007 installed and are unsure if VSTA is installed, you can check quickly by

clicking the Programming option from the Tools menu and then clicking the

Loading Event option. Either the VSTA environment will launch, or you will

be presented with an error message indicating that VSTA is not currently

installed. Figure 18.43 shows the VSTA environment presented when the

user clicks the aforementioned Loading Event menu option. Notice that the

code is set by default to Visual Basic. If you would prefer to code in C#, you

can change the language preference from the Programming category on the

Form Options dialog (Figure 18.44). This setting should be defined prior to

launching VSTA for your form template.

The VSTA environment gives you access to the InfoPath object model,

in addition to key development tools such as a debugger, IntelliSense, and

the object browser. You can think of VSTA as bringing Visual Studio 2005

into the InfoPath 2007 client. It contains subset of the features that Visual

Studio 2005 is equipped with, but at the same time provides the fully func-

tional InfoPath client.

Another option for developing code for your form templates comes in

the form of Visual Studio 2005 Tools for Office Second Edition (VSTO SE).

You can think of VSTO SE as bringing the InfoPath 2007 client into Visual

Studio 2005. It contains a subset of the features with which InfoPath 2007 is

equipped but at the same time provides the fully functional Visual Studio

2005 environment. For example, if you want to preview your form, then you

would still need to use the InfoPath client. Figure 18.45 shows an example of

creating a new InfoPath form template with the Visual Studio 2005 inte-

grated design environment. A major advantage of developing your form tem-

plates in this manner is that you are able to view multiple windows at one

time—for example, you are able to view both the designer window and the

code window. The experience is very similar to the SharePoint Designer 2007

development experience.

Let’s take a quick look at how easy it is to attach code to your form tem-

plate. In this example, we’ll use VSTO SE to create a very simple form tem-

plate that contains two textbox controls, txtName and txtHours. We will use

18.8 Adding Code to a Form Template 609

Chapter 18

Figure 18.43

Visual Studio for

Tools environment.

Figure 18.44

Changing the

programming

language setting.

610 18.8 Adding Code to a Form Template

code to automatically populate the txtName control with the name of the

currently logged on user; that will be the extent of our demonstration. The

purpose of this exercise is to walk you through using the VSTO SE develop-

ment environment and show you what additional steps you need to take

when deploying your form template. For example, because your form tem-

plate contains associated code, the security of the form needs to be set to Full

Trust. Full Trust requires the form template to be deployed by an administra-

tor and also requires that the form be digitally signed with a certificate. We’ll

walk you through this process.

If you have not already done so, now would be a good time to install

VSTO SE. VSTO SE can be downloaded from the Microsoft Web site, and

is installed by simply double-clicking the setup file on the system in which

you have both Office 2007 and Visual Studio 2005 installed. VSTO SE

needs to be installed after the InfoPath 2007 client; otherwise, Visual Studio

will not be able to present all the InfoPath 2007 project templates. Another

factor to keep in mind when installing VSTO SE is that if you have two ver-

sions of Office running side by side on the same machine upon which you

wish to install VSTO SE, the installation will fail. To resolve this issue, you

must remove the earlier version of Office (for example, Office 2003) prior to

installing VSTO SE.

Step 1: Attaching code to a form template

1. Launch Visual Studio 2005

Figure 18.45

Visual Studio 2005

Tools for Office

second edition.