I'm storing value expressions in a JSF component with the f:attribute tag, e.g.:
<h:inputText ...>
<f:attribute name="myId1" value="#{bean.prop1}" />
<f:attribute name="myId2" value="#{bean.prop2}" />
<f:attribute name="myId3" value="#{bean.prop3}" />
</h:inputText>
Is there a way to access all of those value expressions programmatically? (without knowlegde of the names myId1, myId2,...)
Section 9.4.2 of the JSF 2.1 specification says that those values are stored "in the component’s ValueExpression Map".
That's the only occurrence of the term "ValueExpression Map" in the complete spec.
How do I access that map?
In the UIcomponent's Method getValueExpression() of the Jboss/Mojarra implementation the map
getStateHelper().get(UIComponentBase.PropertyKeys.bindings)
is used to obtain a single value expression.
I guess that map is a super set of the "ValueExpression Map"?
Can I be sure that all implementations and all inherited (standard) components use that map to store ValueExpressions?
Thanks.
In theory you should be able to see them all by UIComponent#getAttributes():
Map<String, Object> attributes = component.getAttributes();
for (Map.Entry<String, Object> entry : attributes.entrySet()) {
System.out.printf("name=%s, value=%s%n", entry.getKey(), entry.getValue());
}
However, that doesn't work the way as you'd expect. It only returns static attributes. This does not seem to ever going to be fixed/implemented. See also JSF issue 636. I'd suggest to stick to attribtues with predefinied prefix and an incremental numerical suffix, like as you've presented in your example. That's also what I've always used to pass additional information from the component on to custom validators and converters. You can just collect them as follows:
Map<String, Object> attributes = component.getAttributes();
List<Object> values = new ArrayList<Object>();
for (int i = 1; i < Integer.MAX_VALUE; i++) {
Object value = attributes.get("myId" + i);
if (value == null) break;
values.add(value);
}
System.out.println(values);
An alternative to the answer given by BalusC might be to use nested facets or UIParameter components. Facets can be retrieved as a map using getFacets but you probably need to put an additional UIOutput inside each facet to access its value expression.
Nested UIParameters can be accessed by iterating over the components children and checking for instanceof UIParameter. UIParameters have name and value attributes and so could be easily converted to a map.
I have used parameters in a custom component, but I'm not sure how a standard UIInput like in your example reacts to these.
BalusC is right. UIComponent#getAttributes().get(name) gets values from both places - at first from attributes map and then if not found from "value expression map". To put some value you have to call UIComponent#setValueExpression(name, ValueExpression). If value is literal, it gets stored into the attribute map, otherwise into the "value expression map". Everything is ok then.
Related
I have a data table with a POJO object:
<p:dataTable id="table" var="object" sortBy="#{object.name}" sortOrder="DESCENDING">
object has fields id, name, date, size for example. I am able to set default sort field using xhtml, but I want set it from backing bean.
I am able to parse column id when user creates sort request for example name.
public void sortEventListener(AjaxBehaviorEvent actionEvent) {
String id = ((SortEvent) actionEvent).getSortColumn().getColumnKey();
String[] idPath = id.split(":");
sortBy = idPath[idPath.length - 1];
sortOrder = ((SortEvent) actionEvent).isAscending();
}
My task detects which column user wants to sort and persists it to db. After reload the data table should be sorted by this column.
When I set
sortBy="#{bean.sortBy}" // sortBy = name
it's not working and data table is not sorted after rendering the page.
Please help.
If you bind your data table to a org.primefaces.component.datatable.DataTable object in your bean or find the table component in your bean, you can use the table object to set the sortBy value expression programmatically.
To get an idea how PrimeFaces is handling sorting, you can have a look at the source code at GitHub.
When you have the sort column, you can easily get the sort value expression. So, in your listener you could use something like:
UIColumn sortColumn = sortEvent.getSortColumn();
ValueExpression sortByVE = sortColumn.getValueExpression("sortBy");
By the way, you can replace the parameter type AjaxBehaviorEvent with SortEvent in your sort listener method.
Now, store the sortByVE expression, and set it as the sortBy value expression of the bound table when needed:
dataTable.setValueExpression("sortBy", sortByVE);
If you want to create the value expression from scratch, use something like:
FacesContext context = FacesContext.getCurrentInstance();
ExpressionFactory ef = context.getApplication().getExpressionFactory();
ValueExpression ve = ef.createValueExpression(context.getELContext(),
"#{object.name}",
Object.class);
dataTable.setValueExpression("sortBy", ve);
In this example "#{object.name}" is fixed. You should construct it based on the value you get from your sort listener.
If you want to find your table in your bean, OmniFaces Components might be helpful. It also offers a shortcut method to create value expressions.
See also:
How does the 'binding' attribute work in JSF? When and how should it be used?
Programmatically getting UIComponents of a JSF view in bean's constructor
How do I set the value of HtmlOutputTag in JSF?
I want to display name (current user) in a drop down list in JSF. Here name is a dynamic variable that gets populated though some pojo class. The present code that I have is
<f:selectItem itemLabel="#{accessManager.salesManager.displayName} #{' ('.concat(i.m['current user']).concat(') ')}" itemValue="#{accessManager.salesManager.oid}" />
accessManager.salesManager.displayName populates the name on the UI.
#{' ('.concat(i.m['current user']).concat(') ')}" here I am trying to hard code (current user).
But this is throwing exceptions.
Can any one help me in this? It sounds to be a very simple query but I am not used to EL.
Based on your example, the easiest way is to provide an extra function in your managed bean which evaluates if the current user is the current choice or not. Later on, you evaluate that function with a ternary operator, which will decide wether to display the bundled (translated) value or not.
#ViewScoped
public class ChoiceBean{
public List<SalesManager> getSalesManagers(){
return salesManagers;
}
//Checks if your current choice is the current manager(EL 2.2 required to pass the parameter)
public boolean checkIfCurrent(SalesManager manager){
if (manager.getName().equals("Bob")) return true;
return false;
}
}
<f:selectItem
itemLabel="#{manager.name} #{choiceBean.checkIfCurrent(manager) ? i.m['current user'] : ''}" itemValue="#{salesManager.oid}" />
See also:
Passing parameter to JSF action
Ternary operator in JSTL/EL
Another solution is to use a function doing this String concatenation for you. Either
you use the JSTL functions library with fn:join (see enter link description here) or
implement your own static method in EL, and use that one. The method itself would (surprisingly) look like
public static String concat(String string1, String string2) {
return string1.concat(string2);
}
and the call in JSF, nested like #{fn:concat('(',fn:concat(i.m['current user'],')'))}.
But, out of curiosity, why don't you want to add the brackets into the properties file, so the ressource-value holds (current user) instead of current user?
Hope it helps...
So the question is how do I concat '(' & ')' before and after #{i.m['current user'])}
Don't do it the hard way. Just put those parentheses outside the EL expression.
<f:selectItem itemLabel="#{accessManager.salesManager.displayName} (#{i.m['current user']})" itemValue="#{accessManager.salesManager.oid}" />
I'm trying to put an autocomplete that fetches suggestions as a list of Entry<String, Integer>
<p:autoComplete completeMethod="#{suggester.suggestTopics}"
var="x1" itemLabel="#{x1.key}" itemValue="#{x1.value.toString()}"
value="#{topicController.selected}" />
Manged bean code is as follows:
private int selected;
public int getSelected() {
return selected;
}
public void setSelected(int selected) {
this.selected= selected;
}
But this fails saying the Integer class doesn't have method/property named key. If I remove the value attribute from autocomplete then it starts working properly. But when I put value attribute it starts expecting that the object inside var should be of the same type as that inside value attribute. I believe/expect it should be that the object inside itemValue should be of the same type as that inside value attribute.
I want to use POJOs for suggestions but pass just the entity Id to the value
Using :
Primefaces 3.1
JSF 2.1.6
I believe/expect it should be that the object inside itemValue should
be of the same type as that inside value attribute.
Yes this makes sense, and it is the same in the primefaces showcase:
<p:autoComplete value="#{autoCompleteBean.selectedPlayer1}"
id="basicPojo"
completeMethod="#{autoCompleteBean.completePlayer}"
var="p" itemLabel="#{p.name}" itemValue="#{p}"
converter="player" forceSelection="true"/>
As you see is var="p" and itemValue="#{p} where p is an instance of Player. And selectedPlayer1 is also an instance of Player.
I don't know if it works with a Map since the Primefaces example is called "Pojo support" and the suggestions should be a List of elements of the same type as in the value attribute.
I think you want to use the Simple auto complete , but instead you looked at the wrong example on the showcase of the Pojo Support
x1 refers to the int selected - while it expect to be referred to a POJO (with key and value properties.) , that's why you get the message
Integer class doesn't have method/property named key
Or simple use the Simple auto complete
As commented to Matt you dont need to rebuild Player(Pojo) from Db. You can set simply id property of Player(Pojo) and in action method may be utilize this id to fetch it from DB.
In your case in convertor you might do
Entry<String, Integer> e = new Entry<String, Integer>();
e.setId(value) // where value is passed in to convertor in method getAsObject.....
This value will be set to private Entry<String, Integer> selected
I have used Pojo autocomplete but not tried with generic classes.
Hope this helps.
I know the question is outdated but I've had the same problem.
The point is that you have to assign var to p (var="p"). I think it's terribly unobvious (documentation doesnot mention it has to be that way) 'cause I thought I can assign any var name I want.
here is an example :
<h:outputLabel for="category1" value="Cateogry"/>
<h:selectOneMenu id ="category1" value="#{articleManageBean.categoryId1}"
converter="categoryConverter">
<f:selectItems value="#{articleManageBean.categories}" var="category"
itemValue="#{category.id}" itemLabel="#{category.name}" />
</h:selectOneMenu>
and here is the managed bean that I have
#ManagedBean
#SessionScoped
public class ArticleManageBean {
private Long categoryId1;
private List<Category> categories;
//...
}
The categories list gets populated from db, and selectOneMenu gets populated with this list using a converter.
My First question:
If I want to create another selectOneMenu in my jsf page I would have to copy paste the entire thing and just change the value of selectOneMenu to say categoryId2 thus putting another attribute to managed bean called categoryId2. That is not practical. I want to map these values of selectMenu to list items, for instance to an attribute
List<Long> categoryIds;
if I use
<h:selectOneMenu id ="category1" value="#{articleManageBean.categoryIds.[0]}" >
I get an error
javax.el.PropertyNotFoundException: /createArticle.xhtml #47,68 value="#{articleManageBean.categoriesId[0]}": Target Unreachable, 'null' returned null
If I nitialize the Araylist then I get this exception
javax.el.PropertyNotFoundException: /createArticle.xhtml #47,68 value="#{articleManageBean.categoriesId[0]}": null
My second question:
Is there a way to dinamicly write selectOneMenu tags, by that I mean not to copy paste the entire tag, just somehow create a function that take the categoryId parameter and writes automaticaly the tag (somekind of custom tag maybe ?)
Hope you understood my questions
thanks in advance
Use the brace notation instead to specify the index.
<h:selectOneMenu id="category1" value="#{articleManageBean.categoryIds[0]}">
You only need to make sure that you have already prepared the values behind #{articleManageBean.categoryIds}. JSF won't do that for you. E.g.
private List<Long> categoryIds = new ArrayList<Long>();
public ArticleManageBean() {
categoryIds.add(null);
categoryIds.add(null);
categoryIds.add(null);
// So, now there are 3 items preserved.
}
an alternative is to use Long[] instead, this doesn't need to be prefilled.
private Long[] categoryIds = new Long[3]; // So, now there are 3 items preserved.
I am using the Primefaces wizard component. On one tab I am dynamically creating input boxes based on previous tabs input(user type). The inputbox text labels are derived from a list. In my backing bean, I have a map that contains input labels as keys and inputbox inputs as values.
Clicking on next, I would like the map(values) to be updated with the user input (corresponding to the key)
<c:forEach items="#{gdsiGeodataBean.actionCommand.fields}" var="reqs">
<h:outputLabel for="#{reqs.name}" value="#{reqs.name}:* " />
<pou:inputText value="#{gdsiGeodataBean.actionCommand.values['reqs.name']}" required="true" requiredMessage="Input is required."/>
</c:forEach>
My backing bean :
private List<RequiredParam> fields; // +getter (no setter required)
private Map<String, String> values; // +getter (no setter required)
public CommandAction(String actionName, String actionParams, String context) {
this.actionName = actionName;
this.actionParams = actionParams;
this.contextName = context;
//Set up parameters
getRequiredParams();
getOptionalParams();
fields = getFields();
values = new HashMap<String, String>();
}
Essentially what I would like is for the map values to be updated with user inputs from the textinput boxes.
Your approach to bind the input value to a map is not entirely correct.
<pou:inputText value="#{gdsiGeodataBean.actionCommand.values['reqs.name']}" required="true" requiredMessage="Input is required."/>
You're specifying a fixed map key instead of a dynamic map key based on the currently iterated #{reqs}. This way all submitted values will end up in one and same fixed map key "reqs.name", whereby each one overrides each other so that you only get the value of the last field in the map.
You need to remove those singlequotes to make it a really dynamic key.
<pou:inputText value="#{gdsiGeodataBean.actionCommand.values[reqs.name]}" required="true" requiredMessage="Input is required."/>
Unrelated to the concrete question, even though this approach will work when used as-is in your question, the <c:forEach> will fail in certain circumstances. E.g. when used inside a composite component or an iterating JSF component. Rather use <ui:repeat> instead. See also JSTL in JSF2 Facelets... makes sense?