How would i validate series selection in primefaces datatable - jsf

Question

I have scenario where i need to validate series selection of rows in datatable . I need to enable button when the rows are selected in series and disabled when the are not selected in series.
Disable Button
Enable Button
XTML
<p:dataTable id="listStackFormTable" var="stackLine"
scrollRows="80" scrollable="true" rowIndexVar="rowIndex"
value="#{stackEditBean.listStackLineForm}"
selection="#{stackEditBean.stackLinesSelected}"
sortBy="#{stackLine.serialNo}" editingRow="cell" editable="true"
rowKey="#{stackLine}"
styleClass="table-f no-h-scroll stack-Listing">
<p:ajax event="toggleSelect"
listener="#{stackEditBean.rowSelect}"
update="listStackFormTable" process="#this"></p:ajax>
<p:ajax event="rowSelect" listener="#{stackEditBean.rowSelect}"
update="listStackFormTable" process="#this" />
<p:ajax event="rowSelectCheckbox"
listener="#{stackEditBean.rowSelect}"
update="listStackFormTable" process="#this"></p:ajax>
<p:ajax event="rowUnselectCheckbox"
listener="#{stackEditBean.rowUnSelect}"
update="listStackFormTable" process="#this"></p:ajax>
</p:dataTable>
Java
private List<StackLineForm> stackLinesSelected;
private List<StackLineForm> listStackLineForm;
public void rowSelect(SelectEvent event) {
StackLineForm selectedRow = (StackLineForm) event.getObject();
List<StackLineForm> list = new ArrayList<StackLineForm>();
for (StackLineForm form : this.stackLinesSelected) {
list.add(form);
form.setSelectedStackLineFlag(true);
}
this.getDimHarvestBackingBean().setListSelectedDim(list);
this.setStackLinesSelected(list);
}
public void rowUnSelect(UnselectEvent event) {
StackLineForm selectedRow = (StackLineForm) event.getObject();
List<StackLineForm> list = this.stackLinesSelected;
for (StackLineForm form : this.stackLinesSelected) {
if (selectedRow.getSaKey().equals(form.getSaKey())) {
selectedRow.setSelectedStackLineFlag(false);
list.remove(selectedRow);
}
}
this.getDimHarvestBackingBean().setListSelectedDim(list);
this.setStackLinesSelected(list);
}

Answer 1

Just put an ajax event handler for rowUnselectCheckbox and rowSelectCheckbox, and enable/disable the button in the scenario you want.
<p:ajax event="rowSelectCheckbox" listener="#{bean.eventListener}" />
<p:ajax event="rowUnselectCheckbox" listener="#{bean.eventListener}" />

Answer 2

Give your dataTable's selection attribute a new list, the same type of your current list.
put 4 ajax in your dataTable with listener and update, in listeners check two lists to see if your condition is met, put it in a boolean and use it in the disabled attribute of your buttons. don't forget to update the buttons with client id if they're in another form.
<p:dataTable id="datalist"
value="#{bean.items}" var="item"
selection="#{bean.selectedItems}
editable="true"
editMode="cell"
rowKey="#{item.id}">
<p:ajax event="rowSelect" update="form:disabledBtn form:enabledBtn" listener="#{bean.setBtnDisabled()}"/>
<p:ajax event="rowUnselect" update="form:disabledBtn form:enabledBtn" listener="#{bean.setBtnDisabled()}"/>
<p:ajax event="rowSelectCheckbox" update="form:disabledBtn form:enabledBtn" listener="#{bean.setBtnDisabled()}"/>
<p:ajax event="rowUnselectCheckbox" update="form:disabledBtn form:enabledBtn" listener="#{bean.setBtnDisabled()}"/>
<p:column selectionMode="multiple"/>
you can also do the boolean check, client side with javascript, I don't remember much but the general idea is like, take the dataTable dom in your ajax oncomplete, cycle through the children and check for elements with selected class and check your boolean in there, disable your buttons whether with css and pointer-event or with a remoteCommand to switch your boolean. (its the general idea, there're a little more details).