I'm using a triStateCheckbox element with primefaces-extensions 6.0.0 and primefaces 6.0 and it's not renderering the initial value. I created an example view with the three possible values and I still get three empty checkboxes.
This is the example:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:c="http://java.sun.com/jstl/core"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:pe="http://primefaces.org/ui/extensions"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:p="http://primefaces.org/ui">
<f:view locale="#{localeBean.locale}" contentType="text/html">
<h:head>
<h:outputStylesheet library="css" name="standard.css" />
</h:head>
<body>
<h:form id="dataForm" prependId="false" >
<pe:triStateCheckbox value="2" />
<pe:triStateCheckbox value="1" />
<pe:triStateCheckbox value="0" />
</h:form>
</body>
</f:view>
</html>
This is what I get: link to image