Show-HTML method

Use the Show-HTML method to cause the activity to process an HTML rule and send the resulting HTML to a user for display by Internet Explorer. Known as stream processing. this may involve the interpretation of JSP tags (or the older directives), which can access the clipboard to obtain property values, or can insert other HTML rules, and so on.

Use the @baseclass.Show-Harness activity — not this method — to display a work object form defined by a harness rule.

Parameters

This method has three parameters:

Parameter	Description
HTMLStream	Identify the Stream Name key part of an HTML rule (Rule-Obj-HTML rule type) to be processed. The system uses the class of the step page as the Applies To key part of the HTML rule.
HTMLFrame	Optional. Leave blank in most situations. If you use the transid option in a URL JSP tag, the system uses the frame name to verify the transaction ID parameter pzTransactionID. If you enter a value for HTMLFrame, use both the transid and the frame options in the URL JSP tag. (As a best practice, use the name of the primary page as the frame name.) Technically, this frame name is only an assertion to the server engine as to which HTML frame will receive the output, to enable a later redisplay if required. The run-time destination frame is controlled through JavaScript routines in the portal and may differ from this value. When designing and implementing multiThread interactions for a browser-based user session, it is a best practice to have each Thread that uses the Show-HTML method send its HTML to a specific named HTML frame on the browser window, to avoid confusion. See the Pega Developer Network article PRKB-10979 How to use the URL directive to configure transactional HTML forms for more information on synchronizing user input with database transactions when the URL JSP tag or URL directive is used with the transid option.
ReadOnly	Select this box to cause the system to present any HTML INPUT elements on any form as display-only, so that the user receiving the HTML display cannot enter or update data. Clear this box to allow user input, the normal situation.

Results

The system uses rule resolution to access the HTML rule referenced in the first parameter. It uses stream processing to evaluate and process all the JSP tags (or directives) it contains. It sends the resulting processed HTML code using HTTP or HTTPS protocol to the user who ran the activity.

The system stores the processed HTML as the value of the pxThread.pxHTMLStream property on the Thread page.

Checking the method status

This method updates the pxMethodStatus property. See How to test method results using a transition.

Notes

You can't use the Show-HTML method in an activity that has an Activity Type (on the Security tab) of Utility. Utility tasks in a flow do not produce any user interaction.

The Show-Page, Show-Stream, Show-Property and Show-HTML methods each send an HTTP message corresponding to an entire HTML document to the user's Internet Explorer browser. They can't be used in combination to assemble a document. Use Show-Page and Show-Property only for debugging.

To review the HTTP messages produced by the Show-HTML method, install an HTTP debugger such as Fiddler, an open-source Windows-based proxy (or "sniffer" that logs all HTTP traffic between your computer and the Internet. See www.fiddlertool.com.

headless application, stream processing

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