To refresh Apex variable inside Javascript in Visualforce page, move the Javascript inside apex:outputPanel and rerender the apex:outputPanel to refresh Apex variable inside Javascript.
Don’t keep the Javascript snippet in the beginning of the page, move it to the last before </apex:page> tag.
Sample Code:
Visualforce Page:
<apex:page controller=”SampleVFPageController”>
<apex:form id=”pageForm”>
strTemp is {!strTemp}<br/>
<apex:commandButton value=”Testing” reRender=”pageForm,JSPanel”>
<apex:param value=”Test 2″ assignTo=”{!strTemp}”/>
</apex:commandButton>
</apex:form>
<apex:outputPanel id=”JSPanel”>
<script type=”text/javascript”>
console.log( ‘{!strTemp}’ );
</script>
</apex:outputPanel>
</apex:page>
Apex Class:
public class SampleVFPageController {
public String strTemp { get; set; }
public SampleVFPageController() {
strTemp = ‘Test 1’;
}
}
Output:
