Fetch parameters from URLs in Swift

bhavuk chawla

30 August 2024

Greetings readers, today in our Swift learning journey, we will learn how to fetch parameters from URLs in Swift.

In the modern digital world, we use URLs to navigate through web pages to develop an application. Knowing how to fetch parameters from a URL is essential for various purposes, such as retrieving query parameters, tracking user behaviour, or customizing content.

In this blog, we will dive into URLs and will explore methods to extract parameters from a URL in Swift programming.

What are URL Parameters?

URL parameters, commonly known as query parameters or query strings, are key-value pairs appended to the end of a URL. For example, in the URL https://example.com/search?query=webkul&sort=asc&userId=1234.

The URL parameter is commonly used to pass data between web/mobile applications to convey additional information or instructions from the server. Managing these parameters is crucial for developing highly responsive and versatile applications.

How to Fetch Parameters from a URL

Swift provides a robust API for handling URLs with the URLComponents and URLQueryItem classes. In this blog, we will be using URLComponents and URLQueryItem for fetching the parameters from the URL.

For the example, we will be using the “https://example.com/search?query=webkul&sort=asc&userId=1234” URL and will fetch its parameters.

func getQueryParams(from urlString: String) -&gt; &#091;String: String] {
        var parameters: &#091;String: String] = &#091;:]
        
        if let url = URL(string: urlString) {
            let components = URLComponents(url: url, resolvingAgainstBaseURL: false)
            if let queryItems = components?.queryItems {
                for queryItem in queryItems {
                    parameters&#091;queryItem.name] = queryItem.value
                }
            }
        }
        
        return parameters
    }

// output:- &#091;"sort": "asc", "userId": "1234", "query": "webkul"]

func getQueryParams(from urlString: String) -> [String: String] {

var parameters: [String: String] = [:]

if let url = URL(string: urlString) {

let components = URLComponents(url: url, resolvingAgainstBaseURL: false)

if let queryItems = components?.queryItems {

for queryItem in queryItems {

parameters[queryItem.name] = queryItem.value

}

return parameters

}

// output:- ["sort": "asc", "userId": "1234", "query": "webkul"]

Why Fetch URL Parameters?

There are so many reasons for fetching the parameters from the URL but below are the common reason or scenarios:-

Dynamic Content: Adjust content based on user preferences or search criteria.

Tracking and Analytics: Monitor user interactions and behaviours.
State Management: Maintain application state or preferences across sessions.

Conclusion

In this blog, we have learned about the URLs and URL parameters. We have also checked how and why we can fetch the URL parameters from the URL.

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