Web Part Package

A Web Part Package is a CAB file that contains a Web Part library DLL and all its associated .dwp files. You can easily build a Web Part Package with Visual Studio .NET by creating a new CAB project. When you create a Web Part Package, you must add a special header file named manifest.xml because it contains information that STSADM.EXE needs to properly install and configure a Web Part library DLL.

Once you have built a Web Part Package that contains a manifest.xml file, the Web Part library DLL and all the associated .dwp files, you can then install it using the STSADM.EXE administration tool. For example, if you have built a Web Part Package named AcmeWebPartsPack.cab, you can install it using the following command-line instruction:

STSADM.EXE -o AddWPPack -filename AcmeWebPartsPack.cab

When you run this command, the STSADM.EXE utility copies the Web Part library DLL into the \bin directory of each virtual server within the current WSS deployment. You can add the -url parameter to the preceding command-line instruction if you would like to install the Web Part library into only one specific virtual server within the current WSS deployment.

Installing a Web Part Package with STSADM.EXE provides the convenience of adding the required elements to web.config files to configure each Web Part that is being installed as a safe control. This certainly eases large-scale deployment when you are rolling a new Web Part library DLL out into a Web farm environment.

When installing a Web Part Package with the STSADM.EXE utility, you have the option of installing Web Part library DLLs in the GAC. This can be accomplished by using the -globalInstall parameter, as shown here:

STSADM.EXE -o AddWPPack -filename AcmeWebPartsPack.cab -globalInstall

Using this technique makes it possible to install a Web Part library DLL only once per machine, no matter how many virtual servers use it. As mentioned earlier, Web Part library DLLs installed in the GAC are not restricted by the trust level defined inside the web.config file. Therefore, you should not install Web Part library DLLs into the GAC casually. You should only do that when you know that the DLL has come from a trusted source and that it poses no security risk whatsoever.