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POHow can i get the type of elements from a PersistentSet that could be empty
 

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  1. POHow can i get the type of elements from a PersistentSet that could be empty
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    <p>Well, the question explains itself, here is how i tried to do it. I think the problem might be that the Set is empty, and those methods need at least one element to return the class.</p> <p>views/product/_form.gsp</p> <pre><code>&lt;% cl = UnidadProductiva.get(params.unidadProductiva?.id).producto %&gt; &lt;p&gt;${cl}&lt;/p&gt; </code></pre> <p>returns [] </p> <p>if i add this method/attributes after producto:</p> <p><strong>.getCandidateClass() :</strong> No signature of method:<br> org.hibernate.collection.PersistentSet.getCandidateClass() is applicable for argument types: () values: []</p> <p><strong>.class :</strong><br> class org.hibernate.collection.PersistentSet</p> <p><strong>.getElementType() :</strong> No signature of method:<br> org.hibernate.collection.PersistentSet.getElementType() is applicable for argument types: () values: [] Possible solutions: getElement(java.lang.Object)</p> <p><strong>.properties :</strong> </p> <pre><code>{ clearQueueEnabled=true, session=SessionImpl(PersistenceContext[ entityKeys=[ EntityKey[ planificador.UnidadProductiva#1 ] ], collectionKeys=[ CollectionKey[ unidadesProductivas.Cocimiento.producto#1 ], CollectionKey[ planificador.UnidadProductiva.grupoRecursos#1 ], CollectionKey[ planificador.UnidadProductiva.lineaProduccion#1 ] ] ];ActionQueue[ insertions=[ ]updates=[ ]deletions=[ ]collectionCreations=[ ]collectionRemovals=[ ]collectionUpdates=[ ] ]), unreferenced=false, role=unidadesProductivas.Cocimiento.producto, directlyAccessible=false, empty=true, storedSnapshot={ }, operationQueueEnabled=false, value=[ ], owner=unidadesProductivas.Cocimiento: 1, cachedSize=-1, class=classorg.hibernate.collection.PersistentSet, rowUpdatePossible=false, snapshot={ }, key=1, putQueueEnabled=false, dirty=false } </code></pre> <p>i am expecting a method or a property that returns <strong>CaldoMadre</strong></p> <p>And this are the classes i am using</p> <pre><code>class UnidadProductiva {...} class Cocimiento extends UnidadProductiva { static hasMany = [producto:CaldoMadre]; } class Producto { static belongsTo = [unidadProductiva:UnidadProductiva] } class CaldoMadre extends Producto {...} </code></pre> <p>I am a chilean noob to grails, please be patient if i dont undestand.</p>
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    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USandlrc
    1. USuser1919828
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    1. PL
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      1. LTLinked
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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    1. VO
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      1. POHow can i get the type of elements from a PersistentSet that could be empty
      1. This table or related slice is empty.
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    1. COits not immediately obvious to me what `CandidateClass` is/means here. Can you clarify? Also, the results you get from your attempt might shed some light on the problem.
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      1. POHow can i get the type of elements from a PersistentSet that could be empty
      1. USBrian Henry
    2. COthanks, i edited the question
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      1. POHow can i get the type of elements from a PersistentSet that could be empty
      1. USuser1919828
    3. COLooks like a duplicate of http://stackoverflow.com/questions/801940/deriving-class-from-generic-t
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      1. POHow can i get the type of elements from a PersistentSet that could be empty
      1. USAaron Kurtzhals
 

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