Unable to figure out why input parameter is becoming null

Question

This is the script I have in my gsp page:

<script>
function getItemsLength(){
    var id = document.getElementsByName("franchiseID")[0].value(); 
    alert(id); //This displays the intended id
    var itemLength = ${storeCommand.numOfBranches(id)}; //The id becomes null when sent here
} 
</script>

This function is called onclick for a button, I cannot access the id through the store command itself, since the page hasn't been saved yet - it appears as null. Essentially I take in an ID the user gives me for the franchise, and I query to see how many stores have that franchiseID to display it on the screen.

I am new to grails and web development, so let me know if there is anything I am doing wrong!

Answer 1

The fundamental issue you have here is you are trying to mix client-side programming and server-side programming. ${storeCommand.numBranches(id)} is processed when the HTML is rendered and in that case id is not in scope.