Passing parameters with transitions

[dumont]

Hello,
I am in one state of my flow and I want to pass parameter via transition. I've got something like that in my flow definition xml:

<view-state id="allProductsState" view="allProducts">
            <var name="allProducts" class="my.models.package.AllProducts" />
            <on-render>
                <evaluate expression="productService.returnAllProducts(allProducts)"/>
            </on-render>
            <transition on="showProduct" to="singleProduct" />
        </view-state>

        <view-state id="singleProduct" view="singleProduct">
            <var name="product" class="my.models.package.Product" />
            <on-render>
                <evaluate expression="productService.returnProduct(requestParameters.id,product)"/>
            </on-render>
        </view-state>

and this is part of my JSP page when I am in allProductsState state (I am listing all products and want to go to single product):

<a href="${flowExecutionUrl}&_eventId=showProduct&id=${product.id}">Product: ${product.name}</a>

In configuration above I've got exception:

org.springframework.expression.spel.SpelEvaluationException: EL1004E:(pos 12): Method call: Method returnProduct(null,my.models.package.Product) cannot be found on my.service.package.ProductService type
at org.springframework.expression.spel.ast.MethodReference.findAccessorForMethod(MethodReference.java:185)
        at org.springframework.expression.spel.ast.MethodReference.getValueInternal(MethodReference.java:107)
        at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:57)
        at org.springframework.expression.spel.ast.SpelNodeImpl.getTypedValue(SpelNodeImpl.java:102)
        at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:97)
        at org.springframework.binding.expression.spel.SpringELExpression.getValue(SpringELExpression.java:78)
        ... 44 more

[dumont]

I've changed <on-render> to <on-entry> in singleProduct state - it helped.