Using a Pega 7 Activity to Show HTML Page and Access the Activity from Web Browser

An Activity can be used in Pega 7 to process a HTML Rule and send the resulting content to a web browser. This is known in Pega as stream processing. The Activity is accessed with a HTTP request using a URL.

Summary

  1. Create new HTML Rule
  2. Create an Activity to Process HTML Rule using Show-HTML Method
  3. Access the Activity from a Web Browser

Related Posts

  • In the Pega 7 Designer Studio, click on +Create > Technical > HTML to create a new HTML Rule.

Pega7.1.9 Designer Studio Menu - Create HTML Rule

  • Enter a label for the new HTML Rule, select the context, apply to class and ruleset version.
  • Here, the name of the new rule is HelloWorldHTML. Then click on Create and open.

Pega7.1.9 Designer Studio - Create New HTML Rule

  • On the HTML tab of the HTML Rule, select "HTML" in the Generate for drop down.
  • Here, Browser Support is set to "All Supported Browsers" and Accessibility remains "No".
<html>
  <body>
    <span>Hello World!</span>
  </body>
</html>
  • Enter HTML code into the source text box, e.g. the above code shows a Hello World! message.

Pega7.1.9 Designer Studio - Edit HTML Rule, add Hello World in HTML source text box

  • Click on Save to save the changes to the HTML Rule.

  • In the Pega 7 Designer Studio, click on +Create > Technical > Activity to create a new Activity Rule.

Pega7.1.9 Designer Studio Menu - Create Activity Rule

  • Enter a label for the new Activity Rule, select the context, apply to class and ruleset version.
  • Here, the name of the new rule is ViewHelloWorld. Then click on Create and open.

Pega7.1.9 Designer Studio - Create New Activity Rule

  • On the Pages & Classes tab of the Activity rule, add a reference to the class that contains the HTML Rule. Here, that class is PGX-MyStore-Work.

Pega7.1.9 Designer Studio - Edit Activity Rule, Pages and Classes Tab

  • On the Steps tab of the Activity rule, add two steps as shown below.
  • The first step uses Page-New to create a new clipboard page of the class that contains the HTML Rule.
  • The second step uses Show-HTML and references HelloWorldHTML in the HTMLStream parameter.

Pega7.1.9 Designer Studio - Edit Activity Rule, Steps Tab

  • Check the option "Allow direct invocation from the client or a service" on the Security tab of the Activity rule.
  • The option "Require authentication to run" is left unchecked.
  • Leave the Usage dropdown unchanged so that it is set to "Activity".

Pega7.1.9 Designer Studio - Edit Activity Rule, Security Tab

  • Click on Save to save the changes.
  • The activity can now be run by clicking on Actions > Run.
  • On the pop-up Run Activity window, click on Run to execute the activity.

Pega7.1.9 Designer Studio - Run Activity Rule

  • The HTML page, generated by the activity, is shown in a new window:

Pega7.1.9 Designer Studio - Run Activity Rule, Output

  • In Google Chrome, right-click on the page and select View Page Source.

Pega7.1.9 Designer Studio - Run Activity Rule, Output, View Page Source

  • Here, the HTML code is not modified and retains all white spaces and line breaks.
  • The option "Omit extra spaces?" on the HTML Rule form can be used to remove white spaces and line breaks to reduce the size of the generated HTML code.

Pega7.1.9 Designer Studio - Edit HTML Rule, Omit Extra White Spaces

  • The HTML code is now reduced to one line and consecutive white spaces are replaced with a single white space.

Pega7.1.9 - Run Activity Rule, Omit Extra White Spaces

  • The activity can be accessed from an external browser or other HTTP client via a URL.
  • The target activity is referenced in the pyActivity query string parameter using the class- and activity name, here PGX-MyStore-Work.ViewHelloWorld, so that the URL in this example is:
http://localhost:8080/prweb/PRServlet/?pyActivity=PGX-MyStore-Work.ViewHelloWorld
  • If the activity is accessed from the same browser that is used to work in the Designer Studio, the current user’s session will be used to invoke the activity:

Pega7.1.9 - Access Activity Rule from Chrome Web Browser via URL

  • If the activity is accessed from a different browser, where no active session is present, a login screen will be shown:

Pega7.1.9 - Access Activity Rule from Safari Web Browser via URL, Login Screen

  • Use valid Pega operator credentials for authentication when calling the activity (…even when the option "Require authentication to run" is NOT checked, authentication to Pega is needed).

Pega7.1.9 - Access Activity Rule from Safari Web Browser via URL, Active Session

Allow Direct Invocation from the Client or a Service

  • If the option "Allow direct invocation from the client or a service" is NOT checked on the Security tab of the activity:

Pega7.1.9 Designer Studio - Activity Security, Allow direct invocation from the client or a service

  • It is not accessible by an external client and Pega will send an error page:

Pega7.1.9 - Access Activity Rule from Safari Web Browser via URL, Error Page

  • The Pega logs will show a more descriptive error message:
2017-10-31 14:06:35,741 [http-nio-8080-exec-2] [  STANDARD] [          ] [    MyStore:01.01.01]
(internal.mgmt.Executable) ERROR localhost|0:0:0:0:0:0:0:1 [email protected] - 
This activity may not be called directly from input: 
RULE-OBJ-ACTIVITY PGX-MYSTORE-WORK VIEWHELLOWORLD #20171030T210946.682 GMT

Require Authentication to Run Activity

  • If the option "Require authentication to run" is NOT checked, Guest users can run the activity (…if they meet other security and access criteria) using the URL parameter pzAuth:
http://localhost:8080/prweb/PRServlet/?pzAuth=guest&pyActivity=PGX-MyStore-Work.ViewHelloWorld
  • By default, guest users –unauthenticated requestors– can only access rules in the rulesets provided by the access group PRPC:Unauthenticated.
  • This activity is not included in that ruleset and therefore an error page is shown for guest users and an error appears in the Pega 7 logs::
2017-10-31 14:07:04,171 [http-nio-8080-exec-4] [  STANDARD] [          ] [    MyStore:01.01.01] 
(internal.mgmt.Executable) ERROR localhost|0:0:0:0:0:0:0:1 [email protected] - 
This activity may not be called directly from input:
RULE-OBJ-ACTIVITY PGX-MYSTORE-WORK VIEWHELLOWORLD #20171030T210946.682 GMT 
com.pega.pegarules.pub.PRRuntimeException: 
Error: You lack access required to execute PGX-MyStore-Work.ViewHelloWorld
  • For details on how to make the activity accessible to guest users and how to setup different HTML rules for authenticated users and guest users, see the post:

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