# Knowls

## Knowls

This code fragment shows how to apply a javascript-enabled popup bit of knowledge (a knowl).

PG problem file Explanation

$PAR Here is a knowl \{ knowlLink("click me", value=>'This is the inside of a knowl. If you click again, I will go away') \}$PAR

$PAR Here is another knowl \{ knowlLink("click me", url=>'url_of_file_with_information') \}$PAR



Instead of specifying a value, you can specify the url of a file with html in it, and that html will appear in the knowl. Then you can use one file in multiple places.

return knowlLink($display_text, url=>$envir{'localHelpURL'}.\$infoRef);


As another example, here is the last line of the definition of helpLink() where the knowl containing the help message is created after defining the variables which contain the url for the help file.

Knowls can include variables from earlier in the problem. Use knowlLink("link text",escapeSolutionHTML(EV3P("your text with math ~$$math ~$$"))); The escapeSolutionHTML and EV3P are needed to get the math to be handled properly.