Objective-C: How to add query parameter to NSURL?

Question

Let\'s say I have an NSURL? Whether or not it already has an empty query string, how do I add one or more parameters to the query of the NSUR

Answer 1

The answers above mentioned the NSURLComponents,it's a good class to handle URL.

My answer is as follows:

Create a category with NSURL,like NSURL+Additions.h. Then,add the following method and implement it.

- (NSURL *)URLByAppendingQueryParameters:(NSDictionary *)queryParameters
{
    if (queryParameters.count == 0) {
        return self;
    }

    NSArray *queryKeys = [queryParameters allKeys];
    NSURLComponents *components = [[NSURLComponents alloc] initWithURL:self resolvingAgainstBaseURL:NO];
    NSMutableArray * newQueryItems = [NSMutableArray arrayWithCapacity:1];

    for (NSURLQueryItem * item in components.queryItems) {
        if (![queryKeys containsObject:item.name]) {
            [newQueryItems addObject:item];
        }
    }

    for (NSString *key in queryKeys) {
        NSURLQueryItem * newQueryItem = [[NSURLQueryItem alloc] initWithName:key value:queryParameters[key]];
        [newQueryItems addObject:newQueryItem];
    }

    [components setQueryItems:newQueryItems];

    return [components URL];
}

Answer 2

I have an extension to NSURLComponents that add query item, in swift:

extension NSURLComponents {

    func appendQueryItem(name name: String, value: String) {
        var queryItems: [NSURLQueryItem] = self.queryItems ?? [NSURLQueryItem]()
        queryItems.append(NSURLQueryItem(name: name, value: value))
        self.queryItems = queryItems
    }

}

To use,

let components = NSURLComponents(string: urlString)!
components.appendQueryItem(name: "key", value: "value")