Mike’s Musings

A bug was introduced in Grails 0.6 that incorrectly handles boolean properties in views. The Grails generate-all command will generate the controller and views for your domain class. If you have a boolean properties, the GSP tag checkBox will be used to render that property in the various views. The bug introduced will not correctly handle passing the value of the checkBox back to the controller.

A fix has already been published on the Grails site. However, if you don’t want to switch to the Grails 1.0 RC yet and don’t want to rebuild Grails from source, there is an easy workaround. You can create an application taglib and inserted the corrected checkBox code there. Your application taglib will take precedence over the broken one. You also see a warning will running your application. Hopefully this will be your reminder to remove it after upgrading to the next version of Grails.

Create a groovy file whose name ends with TagLib.groovy and place it in /taglib. Below is the contents of mine (again taken from the Grails web site).

class AppTagLib {

    /**
     * checkBox tag fix for 0.6 value bug
     */
     def checkBox = { attrs ->
           def value = attrs.remove('value')
           if (!value) value = "true"
           def test = attrs.remove('test')
           def name = attrs.remove('name')
           out << '<input type="hidden" '
           out << "name=\"_${name}\" />"
           out << '<input type="checkbox" '
           out << "name=\"${name}\" "
           if(test) {
                 out << 'checked="checked" '
           }
           out << "value=\"${value}\" "
           // process remaining attributes
           outputAttributes(attrs)
         // close the tag, with no body
         out << ' />'
     }

    /**
     * Dump out attributes in HTML compliant fashion
     */
    void outputAttributes(attrs)
    {
        attrs.remove( 'tagName') // Just in case one is left
        attrs.each { k,v ->
            out << k << "=\"" << v.encodeAsHTML() << "\" "
        }
    }

}