You can use IntelliStream to create dynamic downloads and updates for your application.

By using IntelliStream technology, you can configure the initial download to only provide the files that are needed to start the application. Then, as the end user runs other parts of the application, the WebClient automatically downloads and installs the additional files as needed. IntelliStream also activates every time the end user starts an application and checks for updated application components. If updated componetns are detected, IntelliStream downloads and installs them before the application starts.

Note: Some IntelliStream System Tasks require Administrator privileges to install. If your application makes use of these tasks, users cannot install personal instances of your WebClient application. For more information, see System Tasks and personal installations.

When an application component reaches the end user's machine, either as part of the initial download or as part of an update, the files within the component are cached. For more information on IntelliStream, see Deploy a WebClient Application.

WebClient codebase locator

As part of defining the application for WebClient, you describe the server that contains the application components to be downloaded, using the Application Assembler. This description is called the codebase locator, which is used by the WebClient to access a server called the codebase server. For more information, see Host your WebClient Deployment

Components and download mode

To download the files for the client portion of the application, WebClient places them in Microsoft cabinet files. Typically, a single cabinet file might contain several procedure (.r) or procedure library (.pl) files, image files, and so on. A single cabinet file comprises an application component.

You assign one of three download modes to each application component:

  • At Startup — The initial download includes the component.
  • As Needed — WebClient automatically downloads the component when the end user uses the part of the application that references it.
  • Ask User at Startup — At the time of the initial download, WebClient prompts end users to identify which As Needed components they want downloaded. WebClient then downloads these components (along with the at-startup components).

For more information, see Deploy a WebClient Application

Component update files

When you define a new version of an application to the Application Assembler, the Application Assembler automatically creates a component update file for each component whose new version contains changed application files. Each component update file represents the delta (difference) between the new version of a component and the previous version of the same component.

When WebClient on the end user's machine determines that the end user's application needs updating, WebClient downloads the necessary component update files to update the end user's installation to the newest version. For more information, see Deploy a WebClient Application

Note: IntelliStream does not support incremental updates to memory-mapped procedure libraries. For more information, see the Updating procedure libraries.

Determining if a resource was modified

When the application deployer generates a new version of an application using the Application Assembler, the Application Assembler determines if an r-code resource has changed since the last version by comparing the each version of the r-code from a version-information file. For more information on the version-information file, see Deploy a WebClient Application

Obsolete versions

When the deployer defines a new version of the application, they can also define certain previous versions as obsolete. For example, if you know that all end users have upgraded beyond a certain version, you might define any earlier version as obsolete. When WebClient generates a new version, it does not produce component update files for obsolete versions. For more information, see Deploy a WebClient Application

System tasks and ABL routine facilities

The IntelliStream System Tasks facility (in the Application Assembler) can perform an array of built-in installation tasks, such as creating desktop shortcuts and registering system files. In addition to the System Tasks facility, WebClient can invoke a ABL routine you supply to perform additional installation tasks. For more information on these facilities, see Deploy a WebClient Application

Note: Some IntelliStream System Tasks require Administrator privileges to install. If your application makes use of these tasks, users cannot install personal instances of your WebClient application. For more information, see the System Tasks and personal installations System Tasks and personal installations.

Digital signatures

By using WebClient you can digitally sign each deployed file. When the end user downloads a file, the end user's WebClient instance validates the digital signature. For complete information on digital signatures in general and how WebClient uses them in particular, see Design for Security