Only variable expressions returning numbers or booleans are allowed in this context
Since Thymeleaf 3.0.10 they fixed a security-bug regarding unescaped code.
Try
<body th:onload="[[${timerEnabled}]] ? 'javascript:runTimer(\'' + [[${timeRemaining}]] + '\');'">Or the recommended way:
<body th:data1="${timerEnabled}" th:data2="${timeRemaining}" th:onload="this.getAttribute('data1') ? javascript:runTimer(this.getAttribute('data2'));">To read more: https://github.com/thymeleaf/thymeleaf/issues/707And:http://forum.thymeleaf.org/Thymeleaf-3-0-10-JUST-PUBLISHED-tt4031348.html#a4031353
I was able to have it working by using this approach
<body><script th:inline="javascript"> /*<![CDATA[*/ var flag = [[${timerEnabled}]]; // if timer should be included or not var timeRemaining = [[${timeRemaining}]]; // the time remaining. window.onload = function() { if(!flag) return; // Exit/Return if the variable is false runTimer(timeRemaining); // Call your favourite method if the variable is true }; /*]]>*/</script>Any other approach such as suggested in the exception is appreciated.
Try it this way.
<body th:onload="${timerEnabled eq true} ? 'javascript:runTimer(\'' + ${timeRemaining} + '\');'">If it doesn't work, you can also try using th:if.
<th:block th:if="${timerEnabled} eq true"> <body th:onload="javascript:runTimer(\'' + ${timeRemaining} + '\');'"> </body></th:block><th:block th:if="${timerEnabled} eq false"> <body></body></th:block>I know, the other version does look much better, but since it is not working, this one is not so bad. Of course, I wouldn't recommend adding it to your bode in this case.
What I find weird, is that I try your code it does work on my end. Who knows why you are getting that error.