[SOLVED] What value is submitted by <html:checkbox> tag when checkbox is unselected in Struts 1?

What value is submitted by <html:checkbox> tag when checkbox is unselected in Struts 1?

I ran into this scenario.

class MyForm extends IdSelectionForm {
  private Boolean approveIt = true;
  .....
}

My JSTL form consists of

<html:checkbox property="approveIt" styleId="style1" value="true"/>

When I select checkbox and submit it, in Struts action I get true value set for this field.

And again when I uncheck it and submit. Then also I get true value. I am wondering if it is something with default value. Should it be overridden by false when I uncheck?

Solution

First of all, <html:checkbox> is a Struts tag not a JSTL tag. This tag simply generates a standard HTML input of type checkbox. And HTML checkboxes send their value as parameter value when they're checked, and don't send any parameter when they're unchecked.

So, since the default value of your form field is true:

if the checkbox is checked, it will be set to true by Struts
if the checkbox is unchecked, it won't be set to anything by Struts, and will thus keep its default value: true

The default value of the approveIt property should be false. That way, if the checkbox is unchecked, it will keep its default value (false), which is correct. And if the checkbox is checked, it will be set to true, which is also correct.