how to log runtime errors in grails - grails

Question

I am trying to debug a simple problem with saving my domain object.
class AppRideOfferController {
def index() {}
def create() {
if(params.fromAddr && params.toAddr && params.preferences && params.startDate) {
RideOffer rideOffer = new RideOffer(startLocation: params.fromAddr, endLocation: params.toAddr, startDateTime: new Date(Integer.parseInt((String) params.startDate)));
rideOffer.save(flush: true);
//assert(rideOffer.id);
log.info("blah");
render(contentType:"text/json") {
result(blah: rideOffer)
};
}
}
}
In the above code, I am simply creating a domain object, saving it, and returning it as json with the generated id in it. However, if I uncomment the asset statement, it fails because id is not set.
I do not get any error on the console, so I wonder how do I get runtime error stacktraces onto the stdout? My Config.groovy's log4j configuration looks like this:
log4j = {
// Example of changing the log pattern for the default console appender:
//
appenders {
console name:'stdout', layout:pattern(conversionPattern: '%c{2} %m%n')
}
info 'grails.app.controllers',
'grails.app.controller',
'grails.app';
error 'org.codehaus.groovy.grails.web.servlet', // controllers
'org.codehaus.groovy.grails.web.pages', // GSP
'org.codehaus.groovy.grails.web.sitemesh', // layouts
'org.codehaus.groovy.grails.web.mapping.filter', // URL mapping
'org.codehaus.groovy.grails.web.mapping', // URL mapping
'org.codehaus.groovy.grails.commons', // core / classloading
'org.codehaus.groovy.grails.plugins', // plugins
'org.codehaus.groovy.grails.orm.hibernate', // hibernate integration
'org.springframework',
'org.hibernate',
'net.sf.ehcache.hibernate'
}

Answer 1

If your code generates a runtime error, you will see the error.gsp view. In the documentation you can see that the save() will not produce an exception, but populate errors that can happen in the validation of your domain class. If you generate your controller you will see how you can handle errors in the save method.
Something like:
def save() {
if(!instance.save(flush:true)) {
//instance fails in validation, you need to respond those errors
Locale locale = RequestContextUtils.getLocale(request) //Locale of the user
render([success: false, errors: errorsToMap(instance.errors, locale)]) as JSON
} else {
render([success: true, record: instance]) as JSON
}
}
//just a helper to format the errors output
private List<Map> errorsToMap(Errors errors, Locale locale) {
def error = []
for(def err : errors.allErrors) {
if(err instanceof FieldError) {
error << [id: err.field, msg: Holders.grailsApplication.mainContext.getMessage(err, locale)]
}
}
return error
}
Holders, JSON and RequestContextUtils are available by default.

Answer 2

Try replacing rideOffer.save(flush: true); with rideOffer.save(flush: true, failOnError:true); and you should see errors in console