Map inside Map with ui:repeat throws UpdateModelException

Question

There is a

Map<String,Map<Double,Double>> priceMatrix

I want to use it in a

<ui:repeat value="#{calcModel.priceMatrix.keySet().toArray()}" var="x">
    <div style="display: inline-block; margin-right: 10px">
        <h:inputText value="#{x}" />
    </div>
    <ui:repeat value="#{calcModel.priceMatrix.get(x).keySet().toArray()}" var="y">
        <div style="display: inline-block; margin-right: 10px">
            <h:inputText value="#{y}" />
        </div>
        <div style="display: inline-block;">
            <h:inputText value="#{calcModel.priceMatrix.get(x).get(y)}" />
        </div>
        <br />
    </ui:repeat>

</ui:repeat>

if i post the formular, i get a UpdateModelException with the Message:

value="#{calcModel.priceMatrix.get(x).get(y)}": Illegal Syntax for Set Operation

This issue is making me terrible since over 6 hours. My first idea was to provide own getter and setter in my bean. This dosn't work because jsf calls the getter before calling the setter.

Is there a solution for my problem?

Would it be better to work with List?

Thank you!

Answer 1

<h:inputText value="#{calcModel.priceMatrix.get(x).get(y)}" />

This is indeed not a writable value expression. This represents a read-only value expression. EL can't figure out how to invoke setters on it as the EL expression represents a chain of method calls not nested properties.

You need to replace it by a writable value expression with help of brace notation [] which represents nested properties.

<h:inputText value="#{calcModel.priceMatrix[x][y]}" />

Your other inputs also don't look good, value="#{x}" is surely also not writable, but you'll by now able to figure out the right syntax: just use #{map[key]} syntax instead of #{key}.

Note that this is not specifically a JSF problem. The root cause your exception as you can find further down in stack trace is a javax.el.PropertyNotWritableException. As its package javax.el says, it's an EL problem, not a JSF one.