About the PowerBuilder window plug-in
The PowerBuilder window plug-in lets you display a PowerBuilder
child window on a Web page viewed in a browser that supports Netscape plug-ins.
Internet Explorer Microsoft Internet Explorer 5.5 Service Pack 2 and later versions
do not support Netscape plug-ins. As a result, the PowerBuilder
window plug-in cannot be used to display PSR reports on those browsers.
Features
The PowerBuilder child window can include all the familiar
controls, including DataWindows, OLE objects, ActiveX (OCX) controls,
and tree controls. You can also open other (pop-up or response)
windows from the child window.
As the user interacts with controls in the child and other
windows, scripts for the controls’ events are executed
just as they are in standalone PowerBuilder applications. Database
access by the plug-in application occurs locally using the client’s
defined database connections.
The objects in the application can be contained in one or
more PowerBuilder Dynamic Libraries (PBDs).
Standard and secure versions
There are two versions of the PowerBuilder window plug-in:
standard and secure.
Standard PowerBuilder window plug-in The standard PowerBuilder window plug-in displays a PowerBuilder
child window in an HTML page. The standard window plug-in is implemented
by NPPBA100.DLL.
Secure PowerBuilder window plug-in The secure PowerBuilder window plug-in is a secure version
of the standard window plug-in. Using the secure version ensures
that PowerBuilder applications downloaded over the Internet do not
damage a client system or access information on a client workstation. The
secure window plug-in is implemented by NPPBS100.DLL.
For considerations to keep in mind when using
the secure version of the PowerBuilder window plug-in, see “Using the secure PowerBuilder
window plug-in”.
Supported browsers
The PowerBuilder window plug-in requires
use of a browser that supports Netscape plug-ins, such as Netscape Navigator
Version 3.x or later. Microsoft Internet Explorer 5.5 Service Pack
2 and later versions do not support Netscape plug-ins.
Security
The standard PowerBuilder window plug-in is a nonsecure application, meaning
that it can access local files and run local applications. These
types of processing are often undesirable in an uncontrolled Web
environment but might be perfectly acceptable on a corporate intranet
where access is controlled.
If security is important at your site, consider using the
secure version of the PowerBuilder window plug-in to build your
application.
Some events always execute in secure mode As of PowerBuilder 7, the application Open event and some
of the Constructor events for controls execute in secure mode even
when you use the standard window plug-in. If your application logic
depends on the ability to perform a nonsecure activity in these
events, such as opening a file for writing, post an event message
to yourself. These are processed once the plug-in returns to standard
mode.
For more about the secure PowerBuilder window
plug-in, see “Using the secure PowerBuilder
window plug-in”.
What kinds of applications make good plug-ins?
HTML forms provide some user interaction by means of a limited
user interface. The PowerBuilder window plug-in takes you beyond
HTML. You can present a fully developed application window with
a rich user interface design to a Web page. You can access data
sources defined on the client workstation.
Examples
Your application might be:
- A data analysis window with master and detail DataWindows
- A user interface design that lets the user make
choices using TreeView, ListView, and PictureListBox controls - A data entry form that processes data on a server
- A data entry form that uses the client’s
defined database connection (either network or local) to process
the data on the client machine - A window that uses PowerBuilder’s OLEControl
control to display an ActiveX control
How the PowerBuilder window plug-in works
The PowerBuilder window plug-in displays a PowerBuilder child
window inside a fixed space reserved on the Web page. The user can
interact with the controls on the page, and the PowerBuilder scripts
for the window and its controls can execute any PowerBuilder code.
When the user switches to another Web page, the PowerBuilder window
is closed and the PowerBuilder DLLs are unloaded from memory.
You include the plug-in on an HTML page using the HTML Embed
element. The Embed element names one or more PBDs that contain PowerBuilder objects
and the name of the child window object that is displayed on the
page.
The PowerBuilder window plug-in implements the Netscape plug-in
API and requires a browser that supports this API (for information,
see “Supported browsers”.)
Client-server interactions, in detail
Table 33-1 describes
in detail what happens between the client and server when the user
views an HTML document with a PowerBuilder window plug-in:
| Step | What the client does | How the server responds |
|---|---|---|
| 1 | The Web browser requests the HTML document from the server |
The server sends a header identifying the document’s MIME type (text/html) |
| 2 | The browser receives the MIME type and prepares to receive an HTML document |
The server sends the HTML document |
| 3 | The browser receives the HTML document and displays it |
— |
| 4 | The browser recognizes the Embed element, reserves space for the plug-in on the page, and requests the PBD file from the server |
The server sends a header identifying the PBD’s MIME type, which can be one of the following:
|
| 5 | The browser receives the MIME type and prepares to receive a PBD file |
The server sends the PBD file |
| 6 | The browser receives the PBD file | — |
| 7 | The browser searches its Plugins directory for the DLL that corresponds to the MIME type (see server step 4) |
— |
| 8 | The browser loads the plug-in DLL | — |
| 9 | The plug-in looks for and loads the PowerBuilder deployment DLLs |
— |
| 10 | If the Embed element includes LIBRARY attributes, then the client requests the specified PBD files |
The server sends a header identifying the PBD’s MIME type (see server step 4) |
| 11 | The browser receives the MIME type and prepares to receive additional PBD files |
The server sends the PBD file |
| 12 | PowerBuilder displays the child window specified in the Embed element |
— |
| 13 | The child window executes its Open script | — |
| 14 | If a script calls the CommandParm function, PowerBuilder queries the browser for the value of the COMMANDPARM attribute in the Embed element |
— |
Requirements
The PowerBuilder window plug-in uses the PowerBuilder runtime
DLLs as well as the plug-in DLL to provide a full range of PowerBuilder
functionality.
Each client that will browse pages containing PowerBuilder
window plug-ins needs supporting software installed on the local
machine:
- PowerBuilder runtime
DLLs - Window plug-in DLL, placed in the Web browser’s Plugins directory
The PowerBuilder window plug-in is especially useful in an
intranet application where you have control over the setup of client
machines.
For details about setting up client machines
on each supported platform, see “Setting up users’ workstations”.
Name
The name of the PowerBuilder window plug-in DLL depends on
whether you are using the standard or secure version:
| Component | Name |
|---|---|
| Standard PowerBuilder window plug-in | NPPBA100.DLL |
| Secure PowerBuilder window plug-in | NPPBS100.DLL |