Difficulty in setting value of a field at runtime

Question

I have a form with input text fields. One of the fields is disabled and automatically filled by the system. I am having problem filling this field at runtime.
What I did was that I tried to set the value of the field during the save operation (that is when I clicked on the save button). The system sets the value of the field but it did not commit the value into the table. This is is the code that I used
    public String SaveParameterRecord() {
       this.codeTypeId.setValue("GB011");
        BindingContainer bindings = getBindings();
        OperationBinding operationBinding = bindings.getOperationBinding("Commit");
        Object result = operationBinding.execute();
        if (!operationBinding.getErrors().isEmpty()) {
            return null;
        return null;
Again I tried with with method call, but it gave me java.lang.NullPointerException at the point (this.codeTypeId.setValue("GB011"))
    public String CheckParameterMethod() {
         BindingContainer bindings = getBindings();
        OperationBinding operationBinding = bindings.getOperationBinding("CreateInsert");
        Object result = operationBinding.execute();
        if (!operationBinding.getErrors().isEmpty()) {
            return null;
         this.codeTypeId.setValue("GB011");  
        return null;

Answer 1

hi Frank,
The issue I see is that by putting this.codeTypeId.setValue("GB011"); wont be updating the model, and that is why after your commit, the value comes null. Is that variable depending on any other value? If you really want to update the model at that stage you will need to do something like;
  public static void setExpressionValue(String expression, Object newValue) {
      FacesContext facesContext = getFacesContext();
      Application app = facesContext.getApplication();
      ExpressionFactory elFactory = app.getExpressionFactory();
      ELContext elContext = facesContext.getELContext();
      ValueExpression valueExp =
          elFactory.createValueExpression(elContext, expression,
                                          Object.class);
      //Check that the input newValue can be cast to the property type
      //expected by the managed bean.
      //If the managed Bean expects a primitive we rely on Auto-Unboxing
      Class bindClass = valueExp.getType(elContext);
      if (bindClass.isPrimitive() || bindClass.isInstance(newValue)) {
          valueExp.setValue(elContext, newValue);
And then instead using this.codeTypeId.setValue("GB011"); you will call setExpressionValue("#{bindings.yourVariable.inputValue}","GB011"). But then again I dont recommend you doing this.
If this variable depends on another variable, you can use a setPropertyListener and autoSubmit=true.
Regards