request parameter setter (not getter!) called multiple times

[hybris]

I have this request scoped bean:

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<managed-bean>
        <managed-bean-name>perioddetail</managed-bean-name>
        <managed-bean-class>
            manager.PeriodDetail
        </managed-bean-class>
        <managed-bean-scope>request</managed-bean-scope>
        <managed-property>
            <property-name>selectedPeriodId</property-name>
            <value>#{param.selectedPeriodId}</value>
        </managed-property>
    </managed-bean>

The page is called by clicking on a link:

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<h:outputLink value="periodDetail.xhtml" rendered="#{phaseStatus.shift != null}">
                                <h:outputText style="text-decoration:underline"  value="Dettaglio"/>
                                <f:param name="selectedPeriodId" value="shift.#{phaseStatus.shift.id}"/>
                            </h:outputLink>

And i have 2 problems and the second is killing me:
1- the setter is called multiple times. I can live with that but why? Is it the same reason regarding getters in JSF?
2- The last call instead of the actual parameter, the setter is called with NULL. This kinda breaks my logic.

Primefaces 2.2RC2, Glassfish V3 with Mojarra 2.0.3

Any hint?

[cagatay.civici]

Why dont you use viewparams and GET support of JSF 2.0, #{param.something} is an old hack way of doing it with JSF 1.2. And also use h:link instead of h:outputLink.

[hybris]

Thanks! Now the setter is called 1 time with the correct value.
I have still a lot to learn about JSF in general, not only about JSF2.

But i have still a problem, in the page i link i have this:

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<p:graphicImage rendered="#{perioddetail.periodYieldChart != null}" value="#{perioddetail.periodYieldChart}"/>

That calls this method:

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public StreamedContent getPeriodYieldChart() {
        System.err.println("get chart " + selectedPeriodId);
        Set<PeriodicStatistics> sp = getSelectedPeriod().getPeriodicStatistics();
        List<PeriodicStatistics> l = new ArrayList<PeriodicStatistics>();
        l.addAll(sp);
        Collections.sort(l, new Comparator<PeriodicStatistics>() {

            @Override
            public int compare(PeriodicStatistics o1, PeriodicStatistics o2) {
                return o1.getStatisticsTimestamp().compareTo(o2.getStatisticsTimestamp());
            }
        });
        JFreeChart chart = Charts.createPeriodYieldGraph(selectedPeriod, l, 0, l.size());
        return chartToStreamedContent(chart);
    }

As you can see i put a println at the beginning.

This is the output i get:

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GRAVE: get chart product.8bdb8d85-efa0-48de-b3dc-82df43a3b177
GRAVE: get chart product.8bdb8d85-efa0-48de-b3dc-82df43a3b177
GRAVE: get chart product.8bdb8d85-efa0-48de-b3dc-82df43a3b177
GRAVE: get chart product.8bdb8d85-efa0-48de-b3dc-82df43a3b177
GRAVE: get chart product.8bdb8d85-efa0-48de-b3dc-82df43a3b177
GRAVE: get chart null

Again a call with an unexpected null value that i do not know how to handle.


Maybe i should move the graph generation out of that method but how to handle the call with the null value? I have to return a StreamedContent and a null value is not tolerated by Primefaces

[kman]

for dealing with conditional rendering with null value, you may try using standard JSF EL Expression operator "empty" instead of comparing it to "null", for example:

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<p:graphicImage rendered="#{!empty perioddetail.periodYieldChart}" value="#{perioddetail.periodYieldChart}" />

cheers

[hybris]

thanks but i think i should understand why i get that null call first

anyway looking at it better, my rendered test is useless since that method never returns null and, worst, throws an NPE

[hybris]

I modified the code this way with no success:

I used the viewParam feature and i removed the old style parameter declaration in the faces-config:

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<f:metadata>
                <f:viewParam name="selectedPeriodId" value="#{perioddetail.selectedPeriodId}"/>
            </f:metadata>

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public void setSelectedPeriodId(String selectedPeriodId) {
        this.selectedPeriodId = selectedPeriodId;
        System.err.println("set id " + selectedPeriodId);
        if(selectedPeriodId == null) {
            return;
        }
        try {
            String ss[] = selectedPeriodId.split("\\.");
            if("shift".equals(ss[0])) {
                selectedPeriod = dBHelperBean.find(Shift.class, ss[1]);
            }
            if("lot".equals(ss[0])) {
                selectedPeriod = dBHelperBean.find(Lot.class, ss[1]);
            }
            if("product".equals(ss[0])) {
                selectedPeriod = dBHelperBean.find(Product.class, ss[1]);
            }
            scPeriodYieldChart = createPeriodYieldChart();
            scPeriodUPHChart = createPeriodUPHChart();
            StreamedContent sc[] = createPeriodInactivitiesChart();
            scPeriodInactivitiesChart = sc[0];
            scPeriodInactivitiesDurationChart = sc[1];
        } catch(PTrackException ex) {
//FIXME
            ex.printStackTrace();
            FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(Utils.fullStacktraceToHtml(ex)));
        }
    }

This way the above setter is called exactly once with a NON null parameter.
In the same method i put the graph generation that before i had in the getter of the graph linked to the graphicImage tag, i also removed the null test

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<p:panel header="Grafici">
                    <p:graphicImage value="#{perioddetail.periodYieldChart}"/>
                </p:panel>

The getter is now very simple as it should be:

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   public StreamedContent getPeriodYieldChart() {
        System.err.println("get chart " + selectedPeriodId);
        return scPeriodYieldChart;
    }

As you see i put some println in the setter and getter to see what happens and here it is:

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GRAVE: set id shift.c6816dce-c063-407b-86ad-431757c33a36
GRAVE: get chart shift.c6816dce-c063-407b-86ad-431757c33a36
GRAVE: get chart shift.c6816dce-c063-407b-86ad-431757c33a36
GRAVE: get chart shift.c6816dce-c063-407b-86ad-431757c33a36
GRAVE: get chart null
GRAVE: get chart null

Again i have calls on the getter and the value of the id i use to generate the graphics is null.
The result is a broken image in the generated page.

[hybris]

update, i learnt i should use f:param but still no way to go around this bit

when i get the periodId parameter it is always null
i found posts about similar problems but i did not understand what they did to solve the problem

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<p:graphicImage id="giYiled" value="#{perioddetail.periodYieldChart}" cache="FALSE">
                        <f:param id="pgiYieldPeriodId" name="periodId" value="aaaaaaargh"/>
                    </p:graphicImage>

public StreamedContent getPeriodYieldChart() {
System.err.println("get chart " + selectedPeriodId);
Map<String,String> map = FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap();
String id = FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap().get("periodId");
System.err.println("id: " + id);
if (id == null) {
return null;
}
return createPeriodYieldChart(id);
}

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<img id="j_idt17:giYiled" src="" alt="" />

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GRAVE: set id product.b635b94a-7896-4379-99a9-9a55fa96a8e4
GRAVE: get chart product.b635b94a-7896-4379-99a9-9a55fa96a8e4
GRAVE: id: null
GRAVE: set id product.b635b94a-7896-4379-99a9-9a55fa96a8e4
GRAVE: get chart product.b635b94a-7896-4379-99a9-9a55fa96a8e4
GRAVE: id: null

[ppaulraj]

is anyone got solution for this problem. Please ring the bell.

[kukeltje]

please please please read the link in my signature and the one about 'new users'... PLEASE....