CODEWITHSUNDEEP
formsgrails
John Little
John Little

Reputation: 12447

grails: how to dynamically construct a form?

I need to create a dynamic form in grails which has various dynamically created input boxes at runtime, which then submits its params to a controller just like a form created at compile time. Any ideas?

The view gsp might look like this:

<g:form controller="report" action="view">          
   <input type="submit" value="Submit">
   <!-- insert some inuput params here at runtime -->
</g:form>

and the action controller would be:

class ReportController {
def view = {
    def someDynamicParam = "someParam"
    if (params["someParam"] != null) {
       ...
    }

The problem is I have no idea how to render the form input fields in a way that grails will understand them on submission.

Upvotes: 0

Views: 1712

Answers (2)

Eddard Stark
Eddard Stark

Reputation: 3595

I would do something like

<g:form controller="report" action="view">          
  <input type="submit" value="Submit">
  <g:if test="${checkIfParamsExists}">
    <input type="text" id="newParamName"/>
  </g:if>
</g:form>

And in the controller side, your code should work fine.

Upvotes: 1

user800014
user800014

Reputation:

To create dynamic input's you need JavaScript. I suggest you to use some framework to make it easier. Taking JQuery as example:

$('<input>').attr({
    type: 'text',
    id: 'foo',
    name: 'foo'
}).appendTo('form');

Then you need to think how to bind it to a Domain Class. Looking at your question I cannot see what you need, but let's make an example where the user can set values:

//domain class
class MyDomainClass {
  String value
}

//javascript to add a new value
$('<input>').attr({
    type: 'text',
    name: 'values'
}).appendTo('form');

//controller submit action
class MyController {
  def save() {
    def values = params.list('values') //get the list of values
    values.each {
      MyDomain instance = new MyDomain(value: it)
      instance.save()
    }
  }
}

The key here is to use the same name in your html, and to use params.list() to transform the submited values in a List.

Upvotes: 1

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