CODEWITHSUNDEEP
grails
jlpp
jlpp

Reputation: 1584

Is there a preferred/standard way in Grails to bind form params to a list of domain objects?

I have three domain classes: MaterialsOfConcern, Material and MaterialStatus setup as such:

class MaterialsOfConcern {
     Material material
     MaterialStatus materialStatus
}

I'd like to create a form where the user is presented with a static list of Materials that already exist in the system. For each Material listed they must select a corresponding MaterialStatus. Is there a standard approach for this?

I was thinking of the following in the gsp:

<g:each var="material" in="${materials}">
    <g:select name="materialStatus[${material.id}].id" from="${MaterialStatus.list()}" value="?" class="many-to-one"/>
</g:each>

Then in the controller just manually parsing the params object for information I need. But I thought there must be a better, more standardized way, using bindData on a Map or Command object or the like.

Upvotes: 0

Views: 798

Answers (1)

Tomas Lin
Tomas Lin

Reputation: 3532

I am not sure if it is actually a better alternative. But Grails does provide a feature where multiple form fields with the same name are grouped as a list.

Using your example, you could simply pass the list of material statuses to your controller and then resolve them based on their list order.

<g:each var="material" in="${materials}">  
   <g:select name="materialStatus" from="${MaterialStatus.list()}"/>
</g:each>

Then, you can get a list of material statuses using the params.list mechanism.

def statuses = params.list( 'materialStatus' )
materials.eachWithIndex{ material, index -> new MaterialOfConcern( material: material, materialStatus: statuses[ index ] )  }

Upvotes: 1

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