Grails empty entry into the database - grails

Question

I have been struggling with trying to create/save multiple instances at once in Grails, now I am almost there with the following code but when I hit save an empty row of options is created, can anyone help me with this
please see these two questions to see what I want to achieve
How to save multiple object from one view using Grails
Grails one to many relationship view
<g:textField name="question" value="${multipleChoiceQuestionInstance?.question}"/><br/>
<div class="fieldcontain ${hasErrors(bean: multipleChoiceQuestionInstance, field: 'options', 'error')} ">
<label for="options">
<g:message code="multipleChoiceQuestion.options.label" default="Options" />
</label>
<ul class="one-to-many">
<g:set var="counter" value="${0}" />
<g:each status="i" in="${multipleChoiceQuestionInstance?.options?}" var="o">
<li>
<g:textField controller="multipleChoiceOption" name="options[${i}].answerOption" action="show" id="${o.id}" value="${o?.encodeAsHTML()}"/>
<g:checkBox name="options[${i}].correctOption" value="${o.correctOption}"/><br/>
</li>
<g:set var="counter" value="${++counter}" />
</g:each>
<li>
<g:textField name="options[${++counter}].answerOption" value=""/>
<g:checkBox name="options[${counter}].correctOption" /><br/>
</li>
<li class="add">
<g:link controller="multipleChoiceOption" action="create" params="['multipleChoiceQuestion.id': multipleChoiceQuestionInstance?.id]">${message(code: 'default.add.label', args: [message(code: 'multipleChoiceOption.label', default: 'MultipleChoiceOption')])}</g:link>
</li>
</ul>
</div>
If you prefer not to click on the link here are the domain classes
Class MultipleChoiceQuestion {
String question
static constraints = {
...
}
static hasMany = [options:MultipleChoiceOption]
class MultipleChoiceOption{
String answerOption
boolean correctOption
MultipleChoiceQuestion question
static constraints = {
...
}
}
}
I am using automatically generated code by grails for the controller, it is as bellow
def create() {
[multipleChoiceQuestionInstance: new MultipleChoiceQuestion(params)]
}
def save() {
println params
def multipleChoiceQuestionInstance = new MultipleChoiceQuestion(params)
if (!multipleChoiceQuestionInstance.save(flush: true)) {
render(view: "create", model: [multipleChoiceQuestionInstance: multipleChoiceQuestionInstance])
return
}
flash.message = message(code: 'default.created.message', args: [message(code: 'multipleChoiceQuestion.label', default: 'MultipleChoiceQuestion'), multipleChoiceQuestionInstance.id])
redirect(action: "show", id: multipleChoiceQuestionInstance.id)
}
def update() {
def multipleChoiceQuestionInstance = MultipleChoiceQuestion.get(params.id)
if (!multipleChoiceQuestionInstance) {
.... //deleted for real estate
return
}
if (params.version) {
//version checking stuff
}
}
multipleChoiceQuestionInstance.properties = params
if (!multipleChoiceQuestionInstance.save(flush: true)) {
render(view: "edit", model: [multipleChoiceQuestionInstance: multipleChoiceQuestionInstance])
return
}
flash.message = message(code: 'default.updated.message', args: [message(code: 'multipleChoiceQuestion.label', default: 'MultipleChoiceQuestion'), multipleChoiceQuestionInstance.id])
redirect(action: "show", id: multipleChoiceQuestionInstance.id)
}

Answer 1

The reason that you are getting an empty row of options is because you are leaving a textfield with name option[counter] blank. This empty value is passed as a parameter to the controller action and it creates a new row with these blank values.
You should remove any blank options before calling
multipleChoiceQuestionInstance.properties = params
You can use something like this :
def emptyOptions = params.options.findAll{!it.answerOption}
params.options.removeAll(emptyOptions)