Develop Reference

Get parameters dynamically from URL in JSP

Assume the URL is
...&q0=aaa&q1=bbb&q2=ccc&q4=ddd...
What I am doing in the JSP file is:
var qs = [];
qs.push("${q0}");
qs.push("${q1}");
qs.push("${q2}");
qs.push("${q3}");
I'd like to access q0...q4 dynamically; something like this:
for (var i = 0; i < 4; i++) {
var temp = "q" + i;
qs.push("${temp}")
}
But I don't know to make it work. Searched the forum but couldn't find an answer. Thanks in advance.

URLSearchParams is supported by a majority of browser
const url = new URL('https://example.com?q0=aaa&q1=bbb&q2=ccc&q4=ddd')
const params = new URLSearchParams(url.search.slice(1))
params.get('q0') // expect "aaa"
params.get('q1') // expect "bbb"
params.get('q2') // expect "ccc"
params.get('q5') // expect null because q5 doesn't exist
Look at the documentation for more methods.

Getting query string parameters from clean/SEO friendly URLs with JavaScript

I've recently switched my site to use clean/SEO-friendly URLs which has now caused me some issues with a JavaScript function I had for grabbing the query string parameters.
Previously I had been using this function:
function getQueryVariable(variable) {
var query = window.location.search.substring(1);
var vars = query.split("&");
for (var i = 0; i < vars.length; i++) {
var pair = vars[i].split("=");
if (pair[0] == variable) {
return pair[1];
}
}
return (false);
}
Which worked fine on things like this as you could just call getQueryVariable("image") and return "awesome.jpg".
I've been playing with the indexOf(); function to try and grab the relevant parameters from the current URL, eg:
var url = window.location.pathname;
var isPage = url.indexOf("page") + 1;
In an attempt to get the array index number of the "page" parameter, and then plus 1 it to move along to the value of that (?page=name > /page/name/)
JavaScript isn't my main language, so I'm not used to working with arrays etc and my attempt to turn this into a new function has been giving me headaches.
Any pointers?

How about something like this? It splits the path and keeps shifting off the first element of the array as it determines key/value pairs.
function getPathVariable(variable) {
var path = location.pathname;
// just for the demo, lets pretend the path is this...
path = '/images/awesome.jpg/page/about';
// ^-- take this line out for your own version.
var parts = path.substr(1).split('/'), value;
while(parts.length) {
if (parts.shift() === variable) value = parts.shift();
else parts.shift();
}
return value;
}
console.log(getPathVariable('page'));

This can be done formally using a library such as router.js, but I would go for simple string manipulation:
const parts = '/users/bob'.split('/')
const name = parts[parts.length - 1] // 'bob'

How to find url parameter # with value in javascript

I need to find url parameter # with value in javascript.
my url is like:
http://rohitazad.com/wealth/tax/how-to-file-your-income-tax-return/newslist/34343443.cms?intenttarget=no&utm_source=newsletter&utm_medium=email&utm_campaign=ETwealth&type=wealth#sid53239948&ncode=23432kjk#%kjimwer
i want to find this value #sid53239948
I find this How can I get query string values in JavaScript?
but how to find this value in url?

EDIT:
This will filter the sid into the sid-variable wherever you put your hash.
var url_arr = window.location.hash.split('&'),
sid = '';
url_arr.filter(function(a, b) {
var tmp_arr = a.split('#')
for (var i in tmp_arr)
if (tmp_arr[i].substring(0, 3) == 'sid')
sid = tmp_arr[i].substring(3, tmp_arr[i].length)
});
console.log(sid) // Will output '53239948'
Old answer:
var hash_array = window.location.hash.split('#');
hash_array.splice(0, 1);
console.log(hash_array);

use this plugin that help you to find exact information
https://github.com/allmarkedup/purl

Try this way,
var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&');
// console.log(window.location.href);
// console.log(hashes);
for(var index = 0; index < hashes.length; index++)
{
var hash = hashes[index].split('=');
var value=hash[1];
console.log(value);
}

http://www.w3schools.com/jsref/jsref_indexof.asp
Search a string for "welcome":
var str = "Hello world, welcome to the universe.";
var n = str.indexOf("welcome");
The result of n will be:13. Maybe this helps you. In the posted link in your question you see how you get the url. But be careful: indexOf only returns the 1st occurence.

The post you have referenced is looking for a URL parameter in a string. These are indicated by:
?{param_name}={param_value}
What you are looking for is the anchor part of the URL or the hash.
There is a simple Javascript function for this:
window.location.hash
Will return:
#sid53239948
See reference:
http://www.w3schools.com/jsref/prop_loc_hash.asp
However, given a URL that has multiple hashes (like you one you provided), you will need to then parse the output of this function to get the multiple values. For that you will need to split the output:
var hashValue = window.location.hash.substr(1);
var hashParts = hashValue.split("#");
This will return:
['sid53239948', '%kjimwer']

Since you have hash values in query params, window.location.hash will not work for you. You can try to create an object of query parameters and then loop over them and if # exists, you can push in a array.
Sample
function getQStoObject(queryString) {
var o = {};
queryString.substring(1).split("&").map(function(str) {
var _tmp = str.split("=");
if (_tmp[1]) {
o[_tmp[0]] = _tmp[1];
}
});
return o
}
var url = "http://rohitazad.com/wealth/tax/how-to-file-your-income-tax-return/newslist/34343443.cms?intenttarget=no&utm_source=newsletter&utm_medium=email&utm_campaign=ETwealth&type=wealth#sid53239948&ncode=23432kjk#%kjimwer";
// window.location.search would look like this
var search = "?intenttarget=no&utm_source=newsletter&utm_medium=email&utm_campaign=ETwealth&type=wealth#sid53239948&ncode=23432kjk#%kjimwer";
var result = getQStoObject(search);
console.log(result)
var hashValues = [];
for(var k in result){
if(result[k].indexOf("#")>-1){
hashValues.push(result[k].split('#')[1]);
}
}
console.log(hashValues)
`

This solution will return you both values following #.
var url = 'http://rohitazad.com/wealth/tax/how-to-file-your-income-tax-return/newslist/34343443.cms?intenttarget=no&utm_source=newsletter&utm_medium=email&utm_campaign=ETwealth&type=wealth#sid53239948&ncode=23432kjk#%kjimwer';
var obj = url.split('?')[1].split('&');
for(var i = 0; i < obj.length; i++) {
var sol = obj[i].split('#');
if(sol[1]) {console.log(sol[1]);}
}

Find any variable that is undefined and hide from url string

I'm currently building a URL string from form inputs to look something similar to this:
api/search/127879/11-28-2013/7/2/undefined/undefined/undefined/LGW/null
How would i find any or all variables that === to undefined and then remove from these from the string above?

if you dont want to chage logic of building url than just make use of replace function of javascript
var str = "api/search/127879/11-28-2013/7/2/undefined/undefined/undefined/LGW/null";
var res = str.replace(/undefined\//gi,"");

If you are generating string yourself, then check before appending it to urlString.
If you get the string from server, then do this:
var finalUrl = "";
var urlStr= "api/search/127879/11-28-2013/7/2/undefined/undefined/undefined/LGW/null";
var urlArray = urlStr.split('/');
for (i = 0, i = urlArray.length; i ++) {
if(urlArray[i] === undefined)
{
//do nothing
}
else
{
finalUrl += urlArray[i];
}
}
Hope this helps.

Can a javascript attribute value be determined by a manual url parameter?

I am trying to display data from an external .jsp file, which is set up something like this:
<tag>
<innertag1 id="1">
<innertag1 id="2">
</tag>
<tag>
<innertag2 id="3">
<innertag2 id="4">
</tag>
To display only information from only one particular "innertag" tag, I'm currently using:
NodeList labs = XMLInfo.getElementsByTagName("innertag1");
I'd like to be able to isolate any particular tag with ease. Theoretically, I could create many individual pages and simply change the values to "innertag2," "innertag3," etc., but this is obviously a bit impractical.
Is there a way to determine the value via a URL parameter? For instance, if I wanted to only display data from "innertag2," is there a way that the url http://www.server.com/data.jsp?id=innertag2 would adjust the tagname properly?
Thank you, any help would be much appreciated.

You can parse document.location.href and extract parameters from there. This is from an old HTML file where I used this technique (not sure if it's compatible on all browsers, however).
var args = {};
function parseArgs()
{
var aa = document.location.href;
if (aa.indexOf("?") != -1)
{
aa = aa.split("?")[1].split("&");
for (var i=0; i<aa.length; i++)
{
var s = aa[i];
var j = s.indexOf("=");
if (j != -1)
{
var name = s.substr(0, j);
var value = s.substr(j + 1);
args[name] = value;
}
}
}
}

Not sure if this is what you're looking for, but you can access parameters from the url using location.search.
6502's answer is almost good enough, it's not url decoding parameters. The function below is a bit more polished (descriptive variable names, no global variables)
function getUrlParams() {
var paramMap = {};
if (location.search.length == 0) {
return paramMap;
}
var parts = location.search.substring(1).split("&");
for (var i = 0; i < parts.length; i ++) {
var component = parts[i].split("=");
paramMap [decodeURIComponent(component[0])] = decodeURIComponent(component[1]);
}
return paramMap;
}
Then you could do
var params = getUrlParams();
XMLInfo.getElementsByTagName(params['id']); // or params.id