Sample app to show that a validation conflict in a numeric input causes the app to blow up if there is also a relationship.
The app has two domain classes, Ping and Pong. One Ping may own several Pongs. A Ping has a weight; it is a numeric (double) property.
The app was created using create-app and generate-all. A minor manual touch-up is log debug messages added to the edit and update methods in the Ping Controller. The log level for controllers is set to DEBUG. BootStrap creates a few domain instances at start-up.
The following text describes how to build and run the app.
You are supposed to set up a Grails environment for your preferred Grails and Gradle versions. Everything is run in development environment.
The root directory contains a bash script setup.sh for picking versions of
Java, Grails and Gradle.
However, it is adapted to the author's system and most likely does not work for you.
It is intended to be sourced into the shell where you run the tests.
Either modify it to suit your needs, or follow your own conventions.
grails
grails> clean
grails> run-app- Browse to the running app
- Under Available Controllers, click pingpong.PingController
- You will se a list containing a single Ping
- Click on its weight (the leftmost field, "9.9")
- You now see the show view of the selected Ping
From here you may do experiments to update the Ping.
- Click the Edit button
- Edit the Weight field to a new value
- Click Update
Changing the weight to anything that does not validate (<0.0, >100.0 or non-numeric input, like "!") causes the app to blow up. Ping validation errors are printed on standard out from the log.debug statement in the Ping controller.
The error message is, in short,
failed to lazily initialize a collection of role: pingpong.Ping.pongs, could not initialize proxy - no Session
The problem is not the invalid input in itself, but the fact that there is a relationship to Pong. After the validation conflict the Ping object is sent back to edit. Edit is supposed to display the object and request valid input. When it tries to display the pongs relationship no session is available. A session is needed to retrieve the associated Pongs.
Integer validation is different, it is done on the client.