Out the box Grails provides two ways to display messages to the user.
Just inside the body div at the top of each gsp view:
<div class="body"> <h1>Create Book</h1> <g:if test="${flash.message}"> <div class="message">${flash.message}</div> </g:if> <g:hasErrors bean="${bookInstance}"> <div class="errors"> <g:renderErrors bean="${bookInstance}" as="list" /> </div> </g:hasErrors>
So we can place messages in flash scope and errors are automatically added to the bookInstance in the case of a failed data binding or save.
We can add errors to the instance if we have an instance.
But if we don’t have an instance then we need something like this:
Create a template gsp in grails-app/views/shared/_messages.gsp:
<g:if test="${flash.message}"> <div class="message">${flash.message}</div> </g:if> <g:if test="${flash.warning}"> <div class="message_error">${flash.warning}</div> </g:if>
Some css just under the original messages entry in main.css:
.message_error { background: #fff3f3 url(../images/skin/exclamation.png) 8px 50% no-repeat; border: 1px solid red; color: #cc0000; margin: 10px 0 5px 0; padding: 5px 5px 5px 0px }
Then at the top of our gsp views change to something like:
<div class="body"> <g:render template="/shared/messages" /> <g:hasErrors bean="${assetInstance}"> <div class="errors"> <g:renderErrors bean="${assetInstance}" as="list" /> </div>
Install and change the templates with ‘grails install-templates’ and edit them if you’d like all future generated gsp’s to use the shared messages template.
grailstutorial.org says:
Displaying error messages in Grails…
Out the box Grails provides two ways to display messages to the user.
Just inside the body div at the top of each gsp view:
Create Book
${flash.message}
…
January 3, 2011, 20:02