CODEWITHSUNDEEP
jspjsfbooleanel
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Reputation: 15453

How to group boolean conditions in EL

I'm having trouble evaluating a pair of boolean expressions within a JSF using EL.

Here's my snippet:

<a4j:commandButton id="addbtn" value="Add School(s)"
  action="#{somebean.someaction}"                       
  disabled="#{not studentRecords.isValid and not studentRecords.schoolSelected}">
</a4j:commandButton>

isValid and schoolSelected are returning boolean result either true or false. But when I'm connection these two with 'and' operator it does not work.

I tried putting 

!studentRecords.isValid and !studentRecords.schoolSelected

But that doesn't also work.

Upvotes: 1

Views: 244

Answers (1)

maple_shaft
maple_shaft

Reputation: 10463

EL expressions will automatically determine the correct managed bean property as long as the setters and getters were written correctly.

Non-Boolean Managed Bean Property

Managed Bean:

private Long studentRecordNumber;

public Long getStudentRecordNumber() {
  return this.studentRecordNumber;
}

public void setStudentRecordNumber(Long studentRecordNumber) {
  this.studentRecordNumber = studentRecordNumber;
}

JSF Markup

rednered="#{studentRecords.studentRecordNumber ne null}"

Boolean Managed Bean Property

Managed Bean:

private boolean valid;

public boolean isValid() {
  return this.valid;
}

public void setValid(boolean valid) {
  this.valid = valid;
}

JSF Markup

rendered="#{not studentRecords.valid and not studentRecords.schoolSelected}"

EL expressions however can also be used to directly evaluate the returned result of a Boolean method, however method parentheses must be used.

rendered="#{studentRecords.canStudentEnrollToday()}"

Upvotes: 4

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