I needed to handle multiple dynamic instances of the same type of validating object in a form within Grails.
Having searched Google and the lists for an out-of-the-box way, or plugin, or pending bug-fix, I found nothing that already provided this capability so ended up writing my own utility.
Given
Map params = [
'chart1.size': '10', // could also be 'chart_1.size' or 'chart_id1.size'
'chart1.height': '100',
'chart1.width': '200',
'chart1.name': 'foo',
'chart2.size': '9',
'chart2.height': '109',
'chart2.width': '209',
'chart2.name': 'blah'
]
The utility function broke the flat structure of the submission into a map of maps, keyed on the id.
static def multiInstanceFormElementsMap = { String groupKey, Set entries ->
Map perInstanceParams = [:]
entries.each {
def matcher = (it.key =~ /${groupKey}([\d+]).(\w+)/);
if (matcher.matches()) {
def instanceId = matcher[0][1]
if (!perInstanceParams[instanceId]) perInstanceParams[instanceId] = [:]
perInstanceParams[instanceId] [matcher[0][2]] = it.value
}
}
return perInstanceParams
}
Usage:
Map result = ControllerUtil.multiInstanceFormElementsMap('chart', params.entrySet())