Develop Reference

replace segment of a URL with regex

I have a button that takes a value from a checkbox and inserts it dynamically into a URL parameter. the URL looks like this:
example.com/search?q=searchterm&site=site1&page=1
&site=site1 is what is being updated dynamically by the value of a checkbox. My code for that looked like below at first:
$("#apply-filter").click(function() {
var filterSite;
var filterSelection;
var filterUrl;
filterSite = "http://" + location.host + location.pathname + location.search;
filterSelection = $('.search-filter-dialog input[type="checkbox"]:checked').val();
filterUrl = '&site=' + filterSelection + '&page=1';
console.log(filterUrl + " - " + filterSite);
window.location.replace(filterUrl);
});
The problem with the first approach is when you click the button multiple times, it just adds the new parameters to the URL, so it ends up looking like:
example.com/search?q=searchterm&site=site1&page=1&site=site2&page=1&site=site3&page=1
When I only need to change &site=site3&page=1 - I tried using a regex to select that part of the URL and replace it with the new one. My attempt at that is below:
$("#apply-filter").click(function() {
var filterSite;
var filterSelection;
var filterUrl;
filterSite = "http://" + location.host + location.pathname + location.search;
filterSelection = $('.search-filter-dialog input[type="checkbox"]:checked').val();
filterUrl = filterSite + '&site=' + filterSelection + '&page=1';
var url = filterUrl.match(/&([^ ]*)/)[1];
console.log(filterUrl + " - " + filterSite);
window.location.replace(url, filterUrl);
});
What this block does is remove the search query and just returns
example.com/site=site1&page=1 which gives a 404.
I need to somehow update a segment of a URL, and not the entire thing. I believe I need to do some sort of regex to target it and change it. What are the next steps? How can I update a certain section of a URL?
EDIT: This is where it stands now:
// apply filter, go to page
$("#apply-filter").click(function() {
var filterSite;
var filterSelection;
var filterUrl;
filterSite = "http://" + location.host + location.pathname + location.search;
filterSelection = $('.search-filter-dialog input[type="checkbox"]:checked').val();
filterUrl = filterSite + '&site=' + filterSelection + '&page=1';
var url = filterUrl.match(/&([^ ]*)/)[1];
// console.log(filterUrl + " - " + filterSite);
if (window.location.href.indexOf("&site=") > -1) {
filterSite.replace(/&site=\d+/,'&site=' + filterSelection);
window.location.replace(filterSite);
console.log(filterSite);
} else {
window.location.replace(filterUrl);
}
});
but the .replace() method doesn't seem to be working.

Correct me if I got it wrong:
You have something like this: example.com/search?q=searchterm&site=site1&page=1 and you need to update ONLY THIS PART: &site=site1.
One way:
filterSite.replace(/&site=site\d+/,'&site=site' + filterSelection);
This works only if the updatable part of the url is ALWAYS going to be of the form &site=site<number>, ie: filterSelection is always a number
anyhow, let me know
REGARDING YOUR EDIT:
Assuming what you mean by The .replace() method won't change the parameter, is that the URL won't change, you are right: when you do this:
filterSite.replace(/&site=\d+/,'&site=' + filterSelection);
what you are modifying is the variable filterSite, the page won't automatically reload to the new url, which I think is what you intend after seeing this other line:
window.location.replace(filterSite);
replace it with:
window.open(filterSite);
to make the page go to the new url
More about window.open and its arguments
One last thing, I noticed you are using /&site=\d+/,'&site=' + filterSelection as args for replace which will not match example.com/search?q=searchterm&site=site1&page=1. So, unless you changed the structure of the url, you might want to look on that too.
let me know

URL Constructor
EXAMPLE: 1
;
var uri = new URL( "http://example.com/search?q=searchterm&site=site1&page=1" );
uri.searchParams.has("q");
>> true
uri.searchParams.set( "site", "site2" );
uri.searchParams.set( "page", "2" );
uri.href;
>> "http://example.com/search?q=searchterm&site=site2&page=2"
;
Browser Suport: ( ? )[ Chrome 49, Firefox 44, Opera 36, IE12 ]

I suggest you to use A POST request method and Jquery has already a method to construct that params to send based in the form
https://api.jquery.com/serialize/

loading saving and showing json results in javascript

I have a php file called rows2.php that shows results like so after entering new fields in a database. It is simply showing the new id of the field :-
{'new_id':'92'}
I want to load this with javascript and add the new_id to existing list with : either side of the number and display it but I seem to be struggling? Many thanks.
The javascript to load the page and get the result is :
$.getJSON("rows2.php", function(result) {
var new_id=console.log(result[0].new_id);
document.getElementById('vehicle_list').value = '' + document.getElementById('vehicle_list').value + 'new_id' + ':';
})

You should use
document.getElementById('vehicle_list').innerHTML = ''+document.getElementById('vehicle_list').innerHTML+'new_id'+':';
instead of
document.getElementById('vehicle_list').value = ''+document.getElementById('vehicle_list').value+'new_id'+':';
.value is used only in case of input elements otherwise you must use .innerHTML

Don't put the variable name (new_id) in quotes.
document.getElementById('vehicle_list').value = '' + document.getElementById('vehicle_list').value + new_id + ':';

Shorthand for "console.log("var: " + var)"?

It would be nice to have a super quick way to do this:
"console.log("var: " + var)"?
Tried this, but not sure if there's a way to get a variable name as a string once it's been passed in, or convert the name string to a reference to the variable...
var mLog = function(varNameStr){
console.log(varNameStr + ": " + _____);
}
EDIT: Judging by the results of googling "get name string of a variable js", it looks like there's no easy way to grab the name string of a variable from the reference (You have to create hash tables or other structures that make it not worthwhile.)
So, the only possible solution would be to convert a string into a reference to the variable. Is that possible in JS?

The following will do the trick. Pass it a variable name in string form.
var mLog = function(varStr){
console.log(varStr + ": " + eval(varStr));
}
Example:
> var strVar = 'A string variable';
> mLog('strVar');
< strVar: A string variable
> var arrVar = [1,2,3];
> mLog('arrVar');
< arrVar: 1,2,3

There is no way to "extract" the variable name, since variables aren't actually data. The closest thing you could do is use it for objects. Something like:
var obj= {
prop: 'value'
};
function mLog(object, prop) {
console.log(prop + ': ' + object[prop];
}
mLog(obj, 'prop');

Getting NaN Error and undefined Error

I have a Problem with my push function in JavaScript.
<script type="text/javascript">
var myArr = []
var len = myArr.length
$.getJSON('daten.json', function(data) {
$.each(data,function(key,value) {
for(var i = 0; i <= len; i++){
myArr.push("<p>" + value.Name+i ," ", value.Nachname+i + "</p>")
}
})
$('.content').html(myArr.join(''))
})
</script>
I need to convert value.Name+i like this = value.Name0, value.Name1 and so on. I got a JSON File and the Keys are Dynamic, so the first entry got Name0 the second Name1 and so on. Now I must print the JSON file on my html page, but how I can write this line:
myArr.push("<p>" + value.Name+i ," ", value.Nachname+i + "</p>")
with my var i which increment in the loop, to call the Keys in my JSON file?
Like value.Name0. Doing value.Name+i and value.Name.i does not work.

It seems to me what you're looking for is something like this:
myArr.push("<p>" + value['Name'+i] ," ", value['Nachname'+i] + "</p>")
This portion of javascript is covered pretty nicely here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_Objects

Take the object property in a variable, use condition to check if it has value or not then concat it
var nameval = value.name;
then use in your javascript variable
nameval+i

You need to convert your i (integer value) to string prior to adding it.
use:
value.Name + i.toString()
here's the jfiddle link: http://jsfiddle.net/kpqmp49o/

access javascript variable into the .ashx page

I have a JavaScript, which returns 2 variables. I just want to access those variables in the generic handler(ashx) page but I can't. Can anybody give some suggestion?
var myArray = [txt, value];
var url = "insertComments.ashx?dat=" + myArray.join();

Change your Javascript :
var url = "insertComments.ashx?datTxt=" + txt + "&" + "datValue=" + value;
and in handler access that values with :
string txt = context.Request.Params["datTxt"];
string val = context.Request.Params["datValue"];