Extract characters in URL after certain character up to certain character - javascript

I'm trying to extract certain piece of a URL using regex (JavaScript) and having trouble excluding characters after a certain piece. Here's what I have so far:
URL: http://www.somesite.com/state-de
Using url.match(/\/[^\/]+$/)[0] I can extract the state-de like I want.
However when the URL becomes http://www.somesite.com/state-de?page=r and I do the same regex it pulls everything including the "?page=r" which I don't want. I want to only extract the state-de regardless of whats after it (looks like usually a "?" follows it)

This might work:
var arr = url.split("/")
arr[arr.length - 1].split("?")[0]

I'd recommend reading up on regular expressions in general. What you want to do here is make the regular expression stop when it hits the ? in the URL.
Using capturing groups to select which part of the match that you want might also be useful here.
Example:
url.match(/(\/[^\/?]+)(?:\?.*)?$/)[1]

I avoid overly complex RegExs when possible, so I tend to do this in multiple steps (with .replace()):
var stripped = url.replace(/[?#].*/, ''); // Strips anything after ? or #
You can now do the simpler transform to get the state, e.g.:
var state = stripped.split('/').pop()

If you want do it by regex try this one:
url.match(/https?:\/\/([a-z0-9-]+\.)+[a-z]+\/([a-z0-9_-])\/?(\?.*)?/)[1]
Or you could do it using JQuery:
var url = 'http://www.somesite.com/state-de?page=r#mark4';
// Create a special anchor element, set the URL to it
var a = $('<a>', { href:url } )[1];
console.log(a.hostname);
console.log(a.pathname);
console.log(a.search);
console.log(a.hash);

Related

Get base url from string with Regex and Javascript

I'm trying to get the base url from a string (So no window.location).
It needs to remove the trailing slash
It needs to be regex (No New URL)
It need to work with query parameters and anchor links
In other words all the following should return https://apple.com or https://www.apple.com for the last one.
https://apple.com?query=true&slash=false
https://apple.com#anchor=true&slash=false
http://www.apple.com/#anchor=true&slash=true&whatever=foo
These are just examples, urls can have different subdomains like https://shop.apple.co.uk/?query=foo should return https://shop.apple.co.uk - It could be any url like: https://foo.bar
The closer I got is with:
const baseUrl = url.replace(/^((\w+:)?\/\/[^\/]+\/?).*$/,'$1').replace(/\/$/, ""); // Base Path & Trailing slash
But this doesn't work with anchor links and queries which start right after the url without the / before
Any idea how I can get it to work on all cases?
You could add # and ? to your negated character class. You don't need .* because that will match until the end of the string.
For your example data, you could match:
^https?:\/\/[^#?\/]+
Regex demo
strings = [
"https://apple.com?query=true&slash=false",
"https://apple.com#anchor=true&slash=false",
"http://www.apple.com/#anchor=true&slash=true&whatever=foo",
"https://foo.bar/?q=true"
];
strings.forEach(s => {
console.log(s.match(/^https?:\/\/[^#?\/]+/)[0]);
})
You could use Web API's built-in URL for this. URL will also provide you with other parsed properties that are easy to get to, like the query string params, the protocol, etc.
Regex is a painful way to do something that the browser makes otherwise very simple.
I know that you asked about using regex, but in the event that you (or someone coming here in the future) really just cares about getting the information out and isn't committed to using regex, maybe this answer will help.
let one = "https://apple.com?query=true&slash=false"
let two = "https://apple.com#anchor=true&slash=false"
let three = "http://www.apple.com/#anchor=true&slash=true&whatever=foo"
let urlOne = new URL(one)
console.log(urlOne.origin)
let urlTwo = new URL(two)
console.log(urlTwo.origin)
let urlThree = new URL(three)
console.log(urlThree.origin)
const baseUrl = url.replace(/(.*:\/\/.*)[\?\/#].*/, '$1');
This will get you everything up to the .com part. You will have to append .com once you pull out the first part of the url.
^http.*?(?=\.com)
Or maybe you could do:
myUrl.Replace(/(#|\?|\/#).*$/, "")
To remove everything after the host name.

How would I write a Regular Expression to capture the value between Last Slash and Query String?

Problem:
Extract image file name from CDN address similar to the following:
https://cdnstorage.api.com/v0/b/my-app.com/o/photo%2FB%_2.jpeg?alt=media&token=4e32-a1a2-c48e6c91a2ba
Two-stage Solution:
I am using two regular expressions to retrieve the file name:
var postLastSlashRegEx = /[^\/]+$/,
preQueryRegEx = /^([^?]+)/;
var fileFromURL = urlString.match(postLastSlashRegEx)[0].match(preQueryRegEx)[0];
// fileFromURL = "photo%2FB%_2.jpeg"
Question:
Is there a way I can combine both regular expressions?
I've tried using capture groups, but haven't been able to produce a working solution.
From my comment
You can use a lookahead to find the "?" and use [^/] to match any non-slash characters.
/[^/]+(?=\?)/
To remove the dependency on the URL needing a "?", you can make the lookahead match a question mark or the end of line indicator (represented by $), but make sure the first glob is non-greedy.
/[^/]+?(?=\?|$)/
You don't have to use regex, you can just use split and substr.
var str = "https://cdnstorage.api.com/v0/b/my-app.com/o/photo%2FB%_2.jpeg?alt=media&token=4e32-a1a2-c48e6c91a2ba".split("?")[0];
var fileName = temp.substr(temp.lastIndexOf('/')+1);
but if regex is important to you, then:
str.match(/[^?]*\/([^?]+)/)[1]
The code using the substring method would look like the following -
var fileFromURL = urlString.substring(urlString.lastIndexOf('/') + 1, urlString.lastIndexOf('?'))

JavaScript RegEx to match url path

I have possible url paths as below
/articles
/payment
/about
/articles?page=1
/articles/hello-world
I would like to match only the main path of the url, expected matches: ['articles', 'payment', 'about', 'articles', 'articles']
So I tried to construct the JavaScript RegEx and came up with as nearest as I can [a-z].*(?=\/|\?), unfortunately it only matches string inside the last two
Please guide
Thanks everyone
https://regex101.com/r/A86hYz/1
/^\/([^?\/]+)/
This regex captures everything between the first / and either the second / or the first ? if they exist. This seems like the pattern you want. If it isn't, let me know and I'll adjust it as needed. Some simple adjustments would be capturing what's between every / as well as capturing the query parameters.
For future reference, when writing regex, try to avoid the lookahead/behind unless you have to as they usually introduce bugs. It's easiest if you stick to using the regular operators.
To access the match, use the regex like this:
var someString = '/articles?page=1';
var extracted = someString.match(/^\/([^?\/]+)/)[1]
or more generally
function getMainPath(str) {
const regex = /^\/([^?\/]+)/;
return str.match(regex)[1];
}

Matching invisible characters in JavaScript RegEx

I've got some string that contain invisible characters, but they are in somewhat predictable places. Typically the surround the piece of text I want to extract, and then after the 2nd occurrence I want to keep the rest of the text.
I can't seem to figure out how to both key off of the invisible characters, and exclude them from my result. To match invisibles I've been using this regex: /\xA0\x00-\x09\x0B\x0C\x0E-\x1F\x7F/ which does seem to work.
Here's an example: [invisibles]Keep as match 1[invisibles]Keep as match 2
Here's what I've been using so far without success:
/([\xA0\x00-\x09\x0B\x0C\x0E-\x1F\x7F]+)(.+)([\xA0\x00-\x09\x0B\x0C\x0E-\x1F\x7F]+)/(.+)
I've got the capture groups in there, but it's bee a while since I've had to use regex's in this way, so I know I'm missing something important. I was hoping to just make the invisible matches non-capturing groups, but it seems that JavaScript does not support this.
Something like this seems like what you want. The second regex you have pretty much works, but the / is in totally the wrong place. Perhaps you weren't properly reading out the group data.
var s = "\x0EKeep as match 1\x0EKeep as match 2";
var r = /[\xA0\x00-\x09\x0B\x0C\x0E-\x1F\x7F]+(.+)[\xA0\x00-\x09\x0B\x0C\x0E-\x1F\x7F]+(.+)/;
var match = s.match(r);
var part1 = match[1];
var part2 = match[2];

How to use href.replace in extjs

how to use href.replace in extjs
This is my sample:
'iconCls': 'icon_' + href.replace(/[^.]+\./, '')
href= http://localhost:1649/SFM/Default.aspx#/SFM/config/release_history.png
Now i want to get text "release_history.png", How i get it.
Thanks
If you just want the filename, it's probably easier to do:
var href = "http://localhost:1649/SFM/Default.aspx#/SFM/config/release_history.png";
var iconCls = 'icon_' + href.split('/').pop();
Update
To get the filename without the extension, you can do something similar:
var filename = "release_history.png";
var without_ext = filename.split('.');
// Get rid of the extension
without_ext.pop()
// Join the filename back together, in case
// there were any other periods in the filename
// and to get a string
without_ext = without_ext.join('.')
some regex solutions (regex including / delimiter)
as in your example code match the start of the url that can be dropped
href.replace(/^.*\//, '')
or use a regex to get the last part of the url that you want to keep
/(?<=\/)[^.\/]+\.[^.]+$/
update
or get the icon name without .png (this is using lookbehind and lookahead feature of regex)
(?<=\/)[^.\/]+(?=\.png)
Not all flavors of regex support all lookaround reatures and I think Javascript only supports lookahead. so probably your solution is this:
[^.\/]+(?=\.png)
code examples here:
http://www.myregextester.com/?r=6acb5d23
http://www.myregextester.com/?r=b0a88a0a

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