inputHidden how to fetch value from backbean - jsf

I have an inputHidden element in a form to which i would like to fetch a property value from the backbean. Here is my JSF code:
<h:form id="imageEditor">
<p:toolbar id="theMenuBar">
<p:toolbarGroup align="left">
...
<p:commandButton value="Quit" ajax="true"
action="#{imageEditorBean.goToMainMenu()}"
icon="ui-icon-close" >
<p:ajax update="#this" immediate="true"/>
</p:commandButton>
</p:toolbarGroup>
</p:toolbar>
...
<p:fieldset id="viewer" legend="Viewer">
<h:inputHidden id="getJSONData" value="#{imageAnnotations.fetchJSONString()}">
</h:inputHidden>
...
My corresponding backbean class is:
#ManagedBean(name="imageAnnotations")
public class ImageAnnotations {
private String jsonString;
public String fetchJSONString () {
jsonString = new String();
...//populate property
return jsonString;
}
public String getJsonString() {
return jsonString;
}
public void setJsonString(String jsonString) {
this.jsonString = jsonString;
}
When the page loads value property of inputHidden field is populated BUT when i press the quit button to switch view the button is not working, and i get the following error:
Caused by: javax.el.PropertyNotWritableException: /views/image-editor.xhtml #110,82 value="#{imageAnnotations.fetchJSONString()}": Illegal Syntax for Set Operation
I have also tried to call my backbean class and populate the jsonString property like:
<h:inputHidden id="getJSONData" value="#{imageAnnotations.jsonString" action="#{imageAnnotations.fetchJSONString()}">
with no luck. Any ideas?

The inputHidden works in the same way as a inputText, except that it's not displayed in the screen. Therefore, the value property has to point to an attribute in the managed bean, with getter and setter. It can't point to a method. You will have to initialize the value of the property either in the constructor or in the #PostConstruct. If in order to populate this property you use a #ManagedProperty or a #EJB, you'll have to do it in the #PostConstruct since in the constructor they haven't been set yet.
<h:inputHidden id="getJSONData" value="#{imageAnnotations.jsonString" >
In the ManagedBean
#ManagedBean(name="imageAnnotations")
public class ImageAnnotations {
private String jsonString;
#PostConstruct
public void init() {
jsonString = ... // populate jsonString
}
// getter & setter for jsonString
}

Related

How to Compare the values JSF selectonemenu

I am developing a JSF application
I have 2 selectOnemenu controls and submit button.
I need to disable the button if the values of 2 fields are equal
<h:selectOneMenu id="from" value="#{currencyBean.history.fromCurrency}" >
<f:selectItems value="#{currencyBean.currency}" var="c" itemValue="#{c}" itemLabel="#{c.name}"/>
</h:selectOneMenu>
<p:outputLabel for="to" value="to:" />
<h:selectOneMenu id="to" value="#{currencyBean.history.toCurrency}" >
<f:selectItems value="#{currencyBean.currency}" var="c" itemValue="#{c}" itemLabel="#{c.name}"/>
</h:selectOneMenu>
<p:commandButton id="calculateButton" value="Convert" update=":convert :historyPanel" onstart="PF('statusDialog').show()" onsuccess="PF('statusDialog').hide()" validateClient="true" ajax="true" action="#{currencyBean.Calculate()}" />
I tried to use onchange with ajax but everytime I change one dropdown the value of the second drowpdown became null in the backbean so I cannot read it.
Here is my backbean
#Named(value = "currencyBean")
#RequestScoped
public class CurrencyBean implements Serializable {
/**
* Creates a new instance of CurrencyBean
*/
private History history;
private Currency currency;
private Date currentDate;
#Inject
private Loginbean loginBean;
private List<History> historyList;
public List<History> getHistoryList() {
int userId = loginBean.getUserId();
if (userId != -1) {
return new HistoryHelper().GetHistoryListByUser(userId);
}
return null;
}
public CurrencyBean() {
history = new History();
}
public History getHistory() {
return history;
}
public void setHistory(History history) {
this.history = history;
}
public Currency[] getCurrency() {
return Currency.values();
}
public Date getCurrentDate() {
return new Date();
}
public void Calculate() {
int userId = loginBean.getUserId();
if (userId != -1) {
new CurrencyClient().Convert(userId, this.history);
}
}
}
any clue ?
My assumption is that all of your problems come from your managed bean scope. You have #Request scope so every request your managed bean will be removed from container, thus when you define onchange="submit()" (this is only my assumption because you haven't define how you implement onchange attribute) and you select value from one selectBox component values for this component is updated but the first one is still null. When you select second selectBox value updated from first selectBox doesn't exists anymore as managed bean has been removed after first request. You should try with wider scope for instance #ViewScope. If it doesn't help then further informations like implementation onchange attribute will be needed

Passing Values from page to other page JSF

I am beginner in java server faces (JSF), I need to pass the content of text input to second page to display it, the same applies for the second page: I want to pass radio buttons values to a third page. I searched and tried a lot without success.
For example I tried
<h:commandButton value="Next" action="#{myBean.execute(input_id.value)}"/>
Execute method is:
public void execute(String value) {
// ...
try{
FacesContext.getCurrentInstance().getExternalContext().dispatch("/Quizy.xhtml?faces-redirect=true");
}
catch(Exception e){
System.out.println("err");
}
}
Any suggestions?
Here are 4 other ways to pass a parameter value from JSF page to other page JSF :
1- Method expression (JSF 2.0)
2- f:param
3- f:attribute
4- f:setPropertyActionListener
1. Method expression
Since JSF 2.0, you are allow to pass parameter value in the method expression like this #{bean.method(param)}.
JSF page
<h:commandButton action="#{user.editAction(delete)}" />
ManagedBean
#ManagedBean(name="user")
#SessionScoped
public class UserBean{
public String editAction(String id) {
//id = "delete"
}
}
2- f:param
Pass parameter value via f:param tag and get it back via request parameter in backing bean.
JSF page
<h:commandButton action="#{user.editAction}">
<f:param name="action" value="delete" />
</h:commandButton>
ManagedBean
#ManagedBean(name="user")
#SessionScoped
public class UserBean{
public String editAction() {
Map<String,String> params =
FacesContext.getExternalContext().getRequestParameterMap();
String action = params.get("action");
//...
}
}
3. f:atribute
Pass parameter value via f:atribute tag and get it back via action listener in backing bean.
JSF page
<h:commandButton action="#{user.editAction}" actionListener="#{user.attrListener}">
<f:attribute name="action" value="delete" />
</h:commandButton>
ManagedBean
#ManagedBean(name="user")
#SessionScoped
public class UserBean{
String action;
//action listener event
public void attrListener(ActionEvent event){
action = (String)event.getComponent().getAttributes().get("action");
}
public String editAction() {
//...
}
}
4. f:setPropertyActionListener
Pass parameter value via f:setPropertyActionListener tag, it will set the value directly into your backing bean property.
JSF page
<h:commandButton action="#{user.editAction}" >
<f:setPropertyActionListener target="#{user.action}" value="delete" />
</h:commandButton>
ManagedBean
#ManagedBean(name="user")
#SessionScoped
public class UserBean{
public String action;
public void setAction(String action) {
this.action = action;
}
public String editAction() {
//now action property contains "delete"
}
}
There are several ways for doing this, but here is one of them.
You will need to save the inputText value into a property of your bean and both your h:inputText and your h:commanButton should be in the same h:form element
Here is a sample code
In your view
<h:form>
...
<h:inputText value={myBean.someValue} />
....
<h:commandButton value="Next" action="#{myBean.execute()}"/>
</h:form>
Your managed bean should be at least session scoped if you want your property (someValue) to be available in different pages. The content of the managed bean should look like this also:
private String someValue;
// Getter and setter for `someValue`
public String execute() {
// ...
return "/Quizy.xhtml?faces-redirect=true";
}
In the second page if you want to retrieve that value, just use #{myBean.someValue}
to have this done, you just need to set the Value of Your component here inputText or radioButton to a Property of your Managed bean or Cdi bean called on the page of course you won't forget to have getter and setter method for ur property in ur bean. Finally be sure that the scope of Ur bean allow it to be alive (with all its properties' value) across the session. Then, from ur end page you may call ur Managed bean or Cdi bean proprety as value of page components

Values of h:inputText inside ui:repeat are not processed

I want to process this form (valueChangueListener is not valid in real case).
This is the back bean:
public class TestBean extends PrivateBaseBean implements Serializable {
private List<String> strings;
#PostConstruct
public void init() {
strings = new ArrayList<String>();
strings.add("");
strings.add("");
strings.add("");
}
public void saveAction(ActionEvent event) {
StringBuilder textToShowInMessage = new StringBuilder();
for (String string : strings) {
textToShowInMessage.append(string);
textToShowInMessage.append("; ");
}
FacesMessage msg = new FacesMessage(super.getBundle().getString(
textToShowInMessage.toString()), "");
FacesContext.getCurrentInstance().addMessage(null, msg);
}
getters... setters...
An the view:
....
<h:form>
<ui:repeat var="string" value="#{testBean.strings}">
<h:inputText value="#{string}" />
<br />
</ui:repeat>
<p:commandButton value="#{msg.save}"
actionListener="#{testBean.saveAction}" icon="ui-icon-disk"
update="#form" />
</h:form>
...
When the form is processed in the back bean string list always is blank.
How to process form intput's inside iteration, without any value changue listener?
There are some screenshots:
The same problem occurs with action or actionListener on
Your problem is not connected with PrimeFaces <p:commandButton>'s behaviour, but rather with a scoping problem that is implicilty created when using the <ui:repeat> tag.
First of all, let's depart from your example. Basically, you've got
<ui:repeat value="#{bean.strings}" var="s">
<h:inputText value="#{s}"/>
</ui:repeat>
with the backing List<String> strings.
The culprit is here: value="#{s}". The exported by <ui:repeat> variable s is visible only within its loop and it is not bound to any managed bean's property, but instead only to a local variable. Put it differently, s is not bound/equal to bean.strings[index] as one would expect and has no knowledge, as we see, where it originated from. So basically, you're off with a unilateral relationship: value from the bean is printed in your input properly, but the reverse is not happening.
The workarounds
Workaround #1: wrapper classes / model objects
The situation can be overcome by using a wrapper object for your class. In case of a string it could be a 'simple mutable string', like below:
public class MString {
private String string;//getter+setter+constructor
}
In this case the iteration will be working as predicted:
<ui:repeat value="#{bean.mstrings}" var="ms">
<h:inputText value="#{ms.string}"/>
</ui:repeat>
with the backing List<MString> mstrings.
Note that if you have your model class, like User, and will change its properties within <ui:repeat> the class itself will be effectively a wrapper, so that the properties will be set appropriately.
Workaround #2: chained property access
Another workaround consists of accessing an element of your collection directly from within a <h:inputText> tag. This way, any such property will be set by accessing the bean, then collection, then setting the property at the desired index. Excessively long, but that's how it is. As to the how question, <ui:repeat> provides for an exported current iteration status variable, varStatus, that will be used to access the array/collection in the managed bean.
In this case the iteration will also be working as predicted:
<ui:repeat value="#{bean.strings}" var="s" varStatus="status">
<h:inputText value="#{bean.strings[status.index]}"/>
</ui:repeat>
with the ordinary backing List<String> strings.
My workaround solution take the value directly from the page:
<ui:repeat id="repeat" value="#{bean.strings}" var="s" varStatus="status">
<h:inputText id="x" value="#{s.field}"/>
<h:commandLink style="margin: .5em 0" styleClass="commandLink" actionListener="#{bean.save(status.index)}" value="#{bundle.Send}"/>
</ui:repeat>
The save method:
public void save(String rowid) {
String jsParam = Util.getJsParam("repeat:" + rowid + ":x");
System.out.println("jsParam: " + jsParam); //persist...
}
The getJsParam method:
public static String getJsParam(String paramName) {
javax.faces.context.FacesContext jsf = javax.faces.context.FacesContext.getCurrentInstance();
Map<String, String> requestParameterMap = jsf.getExternalContext().getRequestParameterMap();
String paramValue = requestParameterMap.get(paramName);
if (paramValue != null) {
paramValue = paramValue.trim();
if (paramValue.length() == 0) {
paramValue = null;
}
}
return paramValue;
}

JSF Dynamic Rendered Component's Value becomes null when the form is submitted

I have a JSF page which renders a text field depending on the value of a drop down using primefaces ajax listner. The dynamic rendering is done fine. but the problem is once I submit the form the the bound value of that textfield doesn't get bound instead it is shown as null.
this is the part of my JSF only the necessary fields are included here
<h:panelGroup id="textPanel" >
<h:form id="main" prependId="false">
<h:outputText value="WorkFlow ID:" />
<h:selectOneMenu id="workFlows" value="#{workFlowSelectionController.selectedWorkFlowId}" >
<p:ajax event="change" listener="#{workFlowSelectionController.dropDownChange}" update="textPanel"/>
<f:selectItems value="#{workFlowSelectionController.allActiveworkFlows}"/>
</h:selectOneMenu>
<p:inputText value="#{workFlowSelectionController.texField}" rendered="#{workFlowSelectionController.textfieldVisibility}"/>
<p:commandButton ajax="false" value="Next" action="#{workFlowSelectionController.addWorkFlowselectionDetails}"/>
</h:form>
</h:panelGroup>
this is my managed bean
#ManagedBean
#RequestScoped
public class WorkFlowSelectionController {
private boolean textfieldVisibility = false;
private String texField;
public void dropDownChange() {
logger.info("WorkFlowSelectionController.dropDownChange() entered");
if (selectedWorkFlowId != null) {
if (selectedWorkFlowId.equals("-1")) {
textfieldVisibility = true;
operationListStatus = false;
} else {
textfieldVisibility = false;
operationListStatus = true;
}
} else {
textfieldVisibility = false;
operationListStatus = true;
}
public void addWorkFlowselectionDetails() throws CloneNotSupportedException {
System.out.println("Selected Value of Text Field is" + texField);
}
public String getTexField() {
return texField;
}
public void setTexField(String texField) {
this.texField = texField;
}
}
i haven't included the dropdown code of the backing bean. i just need an idea of what i am doing wrong here if i remove the rendered attribute of the textfield it works fine.
thank you
Put the bean in the view scope instead of request scope. A request scoped is recreated on every single HTTP request. The boolean property will default to false again whenever you submit the form, so the submitted value won't be processed then.
#ManagedBean
#ViewScoped
public class WorkFlowSelectionController {
//
}
A view scoped bean will live as long as you're (ajax-) interacting with the same view by returning null or void from action(listener) methods.

h:commandButton inside h:dataTable [duplicate]

This question already has answers here:
How can I pass selected row to commandLink inside dataTable or ui:repeat?
(4 answers)
Closed 7 years ago.
I am using a JSF data table. One of the columns in the table is a Command button.
When this button is clicked I need to pass few parameters (like a value of the selected row) using the Expression language. This paramaters need to be passed to the JSF managed bean which can execute methods on them.
I have used the following snippet of code but the value i am getting on the JSF bean is always null.
<h:column>
<f:facet name="header">
<h:outputText value="Follow"/>
</f:facet>
<h:commandButton id="FollwDoc" action="#{usermanager.followDoctor}" value="Follow" />
<h:inputHidden id="id1" value="#{doc.doctorid}" />
</h:column>
Bean Method:
public void followDoctor() {
FacesContext context = FacesContext.getCurrentInstance();
Map requestMap = context.getExternalContext().getRequestParameterMap();
String value = (String)requestMap.get("id1");
System.out.println("Doctor Added to patient List"+ value);
}
How can I pass values to the JSF managed bean with a commandbutton?
Use DataModel#getRowData() to obtain the current row in action method.
#ManagedBean
#ViewScoped
public class Usermanager {
private List<Doctor> doctors;
private DataModel<Doctor> doctorModel;
#PostConstruct
public void init() {
doctors = getItSomehow();
doctorModel = new ListDataModel<Doctor>(doctors);
}
public void followDoctor() {
Doctor selectedDoctor = doctorModel.getRowData();
// ...
}
// ...
}
Use it in the datatable instead.
<h:dataTable value="#{usermanager.doctorModel}" var="doc">
And get rid of that h:inputHidden next to the h:commandButton in the view.
An -less elegant- alternative is to use f:setPropertyActionListener.
public class Usermanager {
private Long doctorId;
public void followDoctor() {
Doctor selectedDoctor = getItSomehowBy(doctorId);
// ...
}
// ...
}
With the following button:
<h:commandButton action="#{usermanager.followDoctor}" value="Follow">
<f:setPropertyActionListener target="#{usermanager.doctorId}" value="#{doc.doctorId}" />
</h:commandButton>
Related:
The benefits and pitfalls of #ViewScoped - Contains CRUD example using DataModel<E>.

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