Dynamically build the column values - jsf

I am building a component that will build a data table dynamically. I need to pass in the field name from the class and concatenate it to the var attribute of the table. example : "tblVar.firstName". I have tried this using a ui:param as the below code shows, but it just prints the string expression it doesn't evaluate the firstName.
Is there a way to take a string and turn it into an EL expression.
<composite:interface>
<composite:attribute name="pageBean" type="pagecode.app.Maintenence" required="true"/>
<composite:attribute name="dataTableList"/>
<composite:attribute name="columnHeader"/>
<composite:attribute name="columnFieldName"/>
</composite:interface>
<composite:implementation>
<p:dataTable id="doc_code_table" value="#{cc.attrs.pageBean.documentCodeList}"
var="tblVar" rowIndexVar="index" paginator="false">
<ui:param value="#{tblVar}.#{cc.attrs.columnFieldName}" name="colValue"/>
<p:column headerText="#{cc.attrs.columnHeader}">
<h:outputText value="#{colValue}"/>
</p:column>
</p:dataTable>
</composite:implementation>

You're there indeed creating a string variable. The effect is exactly the same as when you do this:
<h:outputText value="#{tblVar}.#{cc.attrs.columnFieldName}" />
This is not right. You should use the brace notation #{bean[property}} to use a variable as property name. Thus, so:
<h:outputText value="#{tblVar[cc.attrs.columnFieldName]}"/>
See also:
Our EL wiki page

Related

Primefaces datatable Identify if the current column is of date type

I am trying to make a common datatable using primefaces.
I want to check if the current column of datatable is of Date type. If it is a Date I want to add DatetimeConverter -
Here is my code -
<ui:component>
<p:dataTable id="#{tableId}" value="#{data}" var="row" styleClass="stdTable vertLines fndTable vertLinesRightBorder"
style="table-layout:fixed; border-color: #dddddd;">
<p:columns value="#{tableColumns}" var="column" sortBy="#{row[column.property]}">
<f:facet name="header">
#{column.header}
</f:facet>
#{row[column.property]}
</p:columns>
</p:dataTable>
</ui:component>
I am calling the above xhtml as follows-
<ui:include src="table.xhtml">
<mbcpos:param name="tableId" value="#{me.id}hTabel1" />
<mbcpos:param name="data" value="#{taskListBean.receivedOwnerTasks}" />
<mbcpos:param name="tableColumns"
value="#{me.columns}" />
</ui:include>
Can we identify the column datatype :
e.g., #{row[column.property]} equals Date
If the column is a date I want to format the date.
Your column model should be where you put the data type it holds and other data type presentation related things like masks, currency, alignment etc.
On the page, for each data type (according to your needs), inside the p:columns
you should do something like this:
<h:outputText rendered="#{column.dateType}" value="#{row[column.property]}">
<f:convertDateTime pattern="dd/MM/yyyy"/>
</h:outputText>

How to get rid of empty tooltips while displaying error messages on tooltips in PrimeFaces?

I display error messages somewhere on <p:tooltip> as follows.
<p:inputText id="text" value="#{bean.text}" required="true"/>
<p:tooltip for="text">
<p:message for="text"/>
</p:tooltip>
Although it displays an error message the given tooltip, an empty/unnecessary tooltip is shown, when there is no error as can be seen in the following picture - beside the bottom right corner of the text box.
How to get rid of such empty tooltips? (I tried someway but it did not work)
It can be done by checking for an error message in the list java.util.List<FacesMessage> that can be obtained by using facesContext.messageList.
The rendered attribute of <p:tooltip> can be set based on the error message/s found in the list for the associated component/s something along the line.
rendered="#{not empty facesContext.getMessageList('clientId')}"
A working code snippet :
<h:form id="form">
<p:panel id="panel">
<p:inputText id="text" value="#{bean.text}" required="true"/>
<p:tooltip for="text" rendered="#{not empty facesContext.getMessageList('form:text')}">
<p:message for="text"/>
</p:tooltip>
<p:commandButton value="Submit" update="panel"/>
</p:panel>
</h:form>
Or by using component binding. Such as,
<p:inputText id="text" binding="#{inputComponent}" value="#{bean.text}"/>
<p:tooltip for="text" rendered="#{not empty facesContext.getMessageList(inputComponent.clientId)}">
<p:message for="text"/>
</p:tooltip>
Or even
<p:inputText id="text" binding="#{inputComponent}" value="#{bean.text}"/>
<p:tooltip for="text" rendered="#{not inputComponent.valid}">
<p:message for="text"/>
</p:tooltip>
The last two cases are useful especially when the (input) component is enclosed within an iterating component like a <p/h:dataTable>, <p:dataGrid>, <p:dataList> (or even <ui:repeat>) where the uniqueness of enclosing components is determined based on the iterating row index of an iterating component such as, form:dataTable:0:text, form:dataTable:1:text, form:dataTable:2:text... and so on
p:tooltip should have a "rendered" attribute, set it to false
from documentation:
rendered : default=TRUE - value to specify the rendering of the
component, when set to false component will not be rendered.
Source: http://courses.coreservlets.com/Course-Materials/pdf/jsf/primefaces/users-guide/p-tooltip.pdf

jsf make ui:param result static

I am using templating and pass some values by to use them in the template:
<ui:repeat var="entry" value="#{showEntriesBean.entries}" id="repeatId">
<ui:include src="/templates/entryTemplate.xhtml">
<ui:param name="prePath" value="/" />
<ui:param name="allowedToSee" value="#{bean.calcRandom(0, 10)}" />
</ui:include>
<br />
</ui:repeat>
I found out, that everytime I use the "allowedToSee" variable in my entryTemplate.xhtml, it recalculates its value.
Is there any way to pass the result of calcRandom in a static way? So it is ONCE calculated (when the allowedToSee value is calculated) and performs like a final number? I don't want it to be calculated everytime #{allowedToSee} is used
If you want the value to be held, you should held it somewhere.
What I would do:
1) Create a List<Integer> property.
2) When the values of the entries properties are set, call a method (preRenderEvent? #PostConstruct?) that introduces in your list as many items as there are in entries.
3) Consult that list using the varStatus attribute of ui:repeat
Little more of less, like:
<ui:repeat var="entry" value="#{showEntriesBean.entries}" id="repeatId" varStatus="status">
<ui:include src="/templates/entryTemplate.xhtml">
<ui:param name="prePath" value="/" />
<ui:param name="allowedToSee" value="#{bean.getPrecalculedRandomAt(status.index)}" />
</ui:include>
<br />
</ui:repeat>
More on the varStatus attribute: http://docs.oracle.com/javaee/6/javaserverfaces/2.0/docs/pdldocs/facelets/ui/repeat.html

CommandLink with parameter in actionListener method doesn't work inside f:facet of datatable

I'd like to be able to click the headers in a table to sort the respective columns. When I try to do this with a h:commandLink and pass the column name as a parameter I get an error saying that the commandLink needs to be ended with > or />, which I do. Example:
<h:column>
<f:facet name="header">
<h:commandLink
value="name"
actionListener="#{albumListBean.sort("album_name")}">
</h:commandLink>
</f:facet>
<h:outputText value="#{item.name}" styleClass="tableItem" />
</h:column>
I get the same result using f:ajax or p:commandLink. If I remove the parameter however, I get no error (but of course the sorting doesn't work either).
Is it not allowed to pass a parameter this way inside the f:facet?
The strings inside EL expressions must be expressed inside simple cotes :
<h:commandLink
value="name"
actionListener="#{albumListBean.sort('album_name')}">
</h:commandLink>

JSF composite:attribute with f:attribute conversion error

I'm implementing a JSF component and need to conditionally add some attributes. This question is similar to a previous JSF: p:dataTable with f:attribute results in "argument type mismatch" error, but with a completely different error message, so I raised a new question.
<composite:interface>
<composite:attribute name="filter" required="false" default="false"
type="java.lang.Boolean"/>
<composite:attribute name="rows" required="false" default="15"
type="java.lang.Integer"/>
...
</composite:interface>
<composite:implementation>
<p:dataTable ivar="p" value="#{cc.attrs.dm}">
<c:if test="#{cc.attrs.filter}">
<f:attribute name="paginator" value="#{true}"/>
<f:attribute name="rows" value="#{cc.attrs.rows}"/>
</c:if>
...
<p:dataTable>
</composite:implementation>
This results in an error java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Integer. Even if I manually set this, I get errors:
<f:attribute name="rows" value="15"/> ... argument type mismatch
<f:attribute name="rows" value="#{15}"/> ... java.lang.Long cannot be cast
to java.lang.Integer
If I add the attribute directly, there is no exception and the correct number of rows is diplayed:
<p:dataTable var="p" value="#{cc.attrs.dm}" rows="#{cc.attrs.rows}">
This is indeed an unfortunate corner case with numbers in EL and composite component attributes. There's no solution for this. The type information is not available in #{cc.attrs} when used in <f:attribute> and thus treated as String. The #{15} cannot be represented as an integer in EL either, all numbers are always implicitly treated as Long when the type information is absent. The ClassCastException can be prevented by using a tag file instead of a composite component.
Your best bet is doing the check in the actual rows attribute itself.
<p:dataTable ... rows="#{cc.attrs.filter ? cc.attrs.rows : null}">

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