Question

I’m trying to make a javascript function to change the value of a parameter in the URL with the value inputed in a text box, with no luck. That’s because I’m note a code designer but a graph one.
this is the URL where I need to change the “City” parameter:

http://server/ad_new_customer.php?&city=&uri=http://server/adauga_exp.php

I am generating data in the input text box through a MySQL query with jQuery like this:

<input type='text' id='city' name='city' style="width:190px; align:left;" value="<?php echo $city; ?>" /> </td>
<script type="text/javascript">
//change the value of parameter in the URL function
function changeURI(key, value) {
var query = document.location.search.substring(1);
var query_q = query.split("?");
var vars = query_q[1].split("&");
for (var i = 0; i < vars.length; i++) {
    var pair = vars[i].split("=");
    if (pair[0] == key) {
        vars[i] = pair[0] + "=" + value;
    }
}
return vars.join("&");
}
//jQuery making the auto-suggestion query for the input ID
$().ready(function() {
$("#city").autocomplete("core/exp_city.php", {
    width: 340,
    matchContains: true,
    selectFirst: false
}).return(changeURI("city", this.value}));
});
</script>

How can I make it change the value the parameter on selected value?
Please advise, again, a humble designer.
Thank you!

L.E.

I have made an workaround, changed the changeURI() function with this one:

function changeURI(key, value)
{
key = escape(key); value = escape(value);
var kvp = document.location.search.substr(1).split('&');
var i=kvp.length; var x; while(i--) 
{
    x = kvp[i].split('=');
    if (x[0]==key)
    {
            x[1] = value;
            kvp[i] = x.join('=');
            break;
    }
}
if(i<0) {
    kvp[kvp.length] = [key,value].join('=');
    }else{
//this will reload the page, it's likely better to store this until finished
document.location.search = kvp.join('&'); 
    }

}

Found on StackOverflow and call it from the jQuery query with the $.result() function:

<script type="text/javascript">
$().ready(function() {
$("#city").autocomplete("core/exp_city.php", {
    width: 340,
    matchContains: true,
    selectFirst: false
}).result(function() {changeURI("city",this.value)});
});

</script>

Answer 1

In your example, document.location.search.substring(1) is already getting rid of the question mark: it should return &city=&uri=http://server/adauga_exp.php. Then doing a split on “?” and trying to take the second array element should return undefined, because there are no longer any “?” characters. Skip straight to var vars = query.split("&") at that point, and the rest looks okay to me.