Get the value of URL Parameters - ios

Question

I am trying to get the parameters from a URL using Swift. Let's say I have the following URL:
http://mysite3994.com?test1=blah&test2=blahblah
How can I get the values of test1 and test2?

Answer 1

You can use the below code to get the param
func getQueryStringParameter(url: String, param: String) -> String? {
guard let url = URLComponents(string: url) else { return nil }
return url.queryItems?.first(where: { $0.name == param })?.value
}
Call the method like let test1 = getQueryStringParameter(url, param: "test1")
Other method with extension:
extension URL {
public var queryParameters: [String: String]? {
guard
let components = URLComponents(url: self, resolvingAgainstBaseURL: true),
let queryItems = components.queryItems else { return nil }
return queryItems.reduce(into: [String: String]()) { (result, item) in
result[item.name] = item.value
}
}
}

Answer 2

Step 1: Create URL extension
extension URL {
func valueOf(_ queryParameterName: String) -> String? {
guard let url = URLComponents(string: self.absoluteString) else { return nil }
return url.queryItems?.first(where: { $0.name == queryParameterName })?.value
}
}
Step 2: How to use the extension
let newURL = URL(string: "http://mysite3994.com?test1=blah&test2=blahblah")!
newURL.valueOf("test1") // Output i.e "blah"
newURL.valueOf("test2") // Output i.e "blahblah"

Answer 3

I also made a URL extension, but put the query param lookup into a subscript.
extension URL {
subscript(queryParam:String) -> String? {
guard let url = URLComponents(string: self.absoluteString) else { return nil }
return url.queryItems?.first(where: { $0.name == queryParam })?.value
}
}
Usage:
let url = URL(string: "http://some-website.com/documents/127/?referrer=147&mode=open")!
let referrer = url["referrer"] // "147"
let mode = url["mode"] // "open"

Answer 4

It appears that none of existing answers work when the link leads to a web site created on Angular. This is because Angular's paths often include a # (hash) symbol in all links, which results in url.queryItems always returning nil.
If a link looks like this: http://example.com/path/#/morepath/aaa?test1=blah&test2=blahblah
Then the parameters can only be obtained from url.fragment. With some additional parsing logic added to #Matt's extension, a more universal code would look like this:
extension URL {
subscript(queryParam: String) -> String? {
guard let url = URLComponents(string: self.absoluteString) else { return nil }
if let parameters = url.queryItems {
return parameters.first(where: { $0.name == queryParam })?.value
} else if let paramPairs = url.fragment?.components(separatedBy: "?").last?.components(separatedBy: "&") {
for pair in paramPairs where pair.contains(queryParam) {
return pair.components(separatedBy: "=").last
}
return nil
} else {
return nil
}
}
}
Usage remains same:
let url = URL(string: "http://example.com/path/#/morepath/aaa?test1=blah&test2=blahblah")!
let referrer = url["test1"] // "blah"
let mode = url["test2"] // "blahblah"

Answer 5

Another way of doing this is to create an extension on URL to return the components, and then create an extension on [URLQueryItem] to retrieve the value from the queryItems.
extension URL {
var components: URLComponents? {
return URLComponents(url: self, resolvingAgainstBaseURL: false)
}
}
extension Array where Iterator.Element == URLQueryItem {
subscript(_ key: String) -> String? {
return first(where: { $0.name == key })?.value
}
}
And this is an example of how this could be used:
if let urlComponents = URL(string: "http://mysite3994.com?test1=blah&test2=blahblah")?.components,
let test1Value = urlComponents.queryItems?["test1"] {
print(test1Value)
}