PHP-like string parsing

Question

I'm writing a mini-console of sorts and I'm trying to figure out how to extract things from a link. For example, in PHP this is a request variable so:

http://somelink.com/somephp.php?variable1=10&variable2=20

Then PHP figures out the url parameters and assigns them to a variable.

How would I parse something like this in Swift?

So, given the string I'd want to take: variable1=10 and variable2=20 etc, is there a simple way to do this? I tried googling around but didn't really know what I was searching for.

I have a really horrible hacky way of doing this but it's not really extendable.

Airspeed Velocity · Accepted Answer · 2015-05-21 23:40:02Z

7

You’d be wanting NSURLComponents:

import Foundation

let urlStr = "http://somelink.com/somephp.php?variable1=10&variable2=20"
let components = NSURLComponents(string: urlStr)

components?.queryItems?.first?.name   // Optional("variable1")
components?.queryItems?.first?.value  // Optional("10")

You might find it helpful to add a subscript operator for the query items:

extension NSURLComponents {
    subscript(queryItemName: String) -> String? {
        // of course, if you do this a lot, 
        // cache it in a dictionary instead
        for item in self.queryItems ?? [] {
            if item.name == queryItemName {
                return item.value
            }
        }
        return nil
    }
}

if let components = NSURLComponents(string: urlStr) {
    components["variable1"] ?? "No value"
}

edited May 21, 2015 at 23:40

answered May 21, 2015 at 23:06

Airspeed Velocity

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3 Comments

Scott Over a year ago

hmm components?.queryItems?.first?.value doesn't seem to return anything?

Scott Over a year ago

also what about variable2? or any other variable other than first?

Airspeed Velocity Over a year ago

first is just a quick way to get the first value in an array while being safe in case the array is empty (unlike queryItems?[0] which will blow up if there are no query items. For multiple values, you can do for…in over it, have added more code.

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