JSF links in table not updating, sorting not swapping - jsf

Question

I have a table displayed. When the user clicks on the headers i want the table to reorganise itself, sorted according to the selected header. Clicking on the same header again, swaps the order of sorting
Within the table, there are several commandLinks.
Now, the problems are as follows
the first update to the sorting order happens, but clicking on the header again will not swap the order.
When the table is refreshed, the links have their value changed, but the link still maps to the object that was previously there
Code:
Table:
<h:form title="table">
<h:dataTable value="#{employee.employeeList}" var="a"
styleClass="order-table" headerClass="order-table-header"
rowClasses="order-table-odd-row,order-table-even-row"
style="width:100%">
<h:column>
<f:facet name="header"><h:commandLink value="Number" action="#{employee.sortByNumber()}" /></f:facet>
<h:commandLink value="#{a.number}" action="#{employee.setEmp(a)}" />
</h:column>
...
...
...
</h:dataTable>
</h:form>
Employee Bean:
public String filter = ""; //has getters and setters
public String order = ""; //has getters and setters
public static final String ORDER_ASCENDING = "asc";
public static final String ORDER_DESCENDING = "desc";
public static final String FILTER_NUMBER = "number";
public void sortByNumber(){
if(filter.equals(FILTER_NUMBER)){
swapOrder();
}else{
filter = FILTER_NUMBER;
order = ORDER_ASCENDING;
}
refreshPage();
}
public void swapOrder(){
if(order.equals(ORDER_ASCENDING)){
order = ORDER_DESCENDING;
}else{
order = ORDER_ASCENDING;
}
}
public void refreshPage(){
FacesContext context = FacesContext.getCurrentInstance();
String viewId = context.getViewRoot().getViewId();
ViewHandler handler = context.getApplication().getViewHandler();
UIViewRoot root = handler.createView(context, viewId);
root.setViewId(viewId);
context.setViewRoot(root);
}
public String setEmp(Employee employee) {
this.employee = employee;
return "details"; //redirects to the details page where the employee set in the previous line is used
}