How could I build a search application using XForms

Question

I working on a search application using XForms standards. the applications searches a small xml file that contains students data. I've written the queries using XQuery and I've tried them out. queries results are fine, very fine. but when I connect them using XForms with the instance and submissions, the presentation layer(a xf:repeat table, each raw is a student) doesn't get updated at all. I know that the queries are valid. the presentation is good but I'm not sure. My question could please help me make a working copy of this application.

the Model is as follow

        <xf:model>
        <xf:action ev:event="xforms-ready">
            <xf:send submission="load-data"/>
        </xf:action>
        <xf:instance xmlns="" id="studInstance">
            <students>
                <student>
                    <idStudent/>
                    <Name/>
                    <LastName/>
                    <Address/>
                </student>
            </students>
        </xf:instance>
        <xf:instance xmlns="" id="search">
            <parameters>
                <query/>
                <field>Name</field>
            </parameters>
        </xf:instance>
        <xf:submission id="load-data" method="get" serialization="none"               action="modules/load.xql" replace="instance" instance="studInstance">
            <xf:message ev:event="xforms-submit-error" level="ephemeral">Load operation failed </xf:message>
            <xf:message ev:event="xforms-submit-done" level="ephemeral">Load operation Succeeded </xf:message>
        </xf:submission>
        <xf:submission id="search" action="modules/search.xql" method="post" serialization="none" ref="instance('search')" targetref="instance('studInstance')" replace="instance">
            <xf:message ev:event="xforms-submit-error" level="ephemeral">Search operation failed </xf:message>
        </xf:submission>
        </xf:model>

the result would be bind-ed to repeat section here:

        <xf:group>
                <xf:repeat instance="studInstance" nodeset="/students/student">
                    <tr>
                        <td>
                            <xf:output ref="idStudent"/>
                        </td>
                        <td>
                            <xf:output ref="Name"/>
                        </td>
                        <td>
                            <xf:output ref="LastName"/>
                        </td>
                        <td>
                            <xf:output ref="Address"/>
                        </td>
                    </tr>
                </xf:repeat>
            </xf:group>

So what's wrong with this code!

Answer 1

The attribute instance has no meaning in a xf:repeat. The correct way of doing what you want is using the instance function inside your XPath:

<xf:repeat nodeset="instance(studInstance)/student">