Retrieving and Parsing Text From Specific Webpage Using Swift - ios

Question

I need to retrieve the text from a specific website. However, I only need a few parts of it. How can I accomplish this using swift.
I have found the following in objective-c, but am not sure it provides how to reference it from a specific site:
NSString *webString = [webView stringByEvaluatingJavaScriptFromString:#"document.documentElement.innerText"];
NSScanner *stringScanner = [NSScanner scannerWithString:webString];
NSString *content = [[NSString alloc] init];
while ([stringScanner isAtEnd] == NO) {
[stringScanner scanUpToString:#"Start of the text you want" intoString:null];
[stringScanner scanUpToString:#"End of the text you want" intoString:&content];
}`
I have put an example of what I mean below:
Again, I would like to accomplish this using Swift.

Answer 1

If your HTML was easily targetable with identifiers or class names, I would suggest using a library such as Kanna. But I've had a look at your page and the text you need is lost amidst an ocean of divs...
So I've quickly hacked a way to get your text with componentsSeparatedByString: I'm cutting the HTML in blocks until I get to the part we're interested in.
Note that it's far from being the most efficient way: instead of using componentsSeparatedByString you should come with a way of identifying the HTML block you want and search for it with NSScanner.
That being said, here's my example of a working hack, tested in a Playground:
enum CustomErrors : String, ErrorType {
case InvalidURL = "Invalid URL"
}
do {
let str = "http://www.golfwrx.com/328370/mizuno-to-offer-custom-grips-at-no-additional-charge/"
guard let url = NSURL(string: str) else { throw CustomErrors.InvalidURL }
let html = try String(contentsOfURL: url)
let separator1 = "<div class='mailmunch-forms-before-post' style='display: none !important;'></div><p>"
let temp = html.componentsSeparatedByString(separator1)
let separator2 = "</p>\n<p>"
let temp2 = temp[1].componentsSeparatedByString(separator2)
let separator3 = "</p><div class='mailmunch-forms-in-post-middle'"
let separated = temp2[1].componentsSeparatedByString(separator3)
let result = separated[0]
print(result)
} catch {
print(error)
}
Note: my example is in Swift 2 (Xcode 7).

Answer 2

Sorry about the specifics, I'm an Objective-C guy. but, here is an example of how to use NString to get the contents of a websites HTML
NSString *url = #"http://www.example.com"; // Your URL
NSURL *urlRequest = [NSURL URLWithString:url]; // Make a request with your URL
NSError *err = nil; // Error handler
NSString *html = [NSString stringWithContentsOfURL:urlRequest encoding:NSUTF8StringEncoding error:&err]; // Try to get the HTML in the string
if(err)
{
//Do something as it didn't work! Maybe a connection problem
}
else
{
// Use NScanner on html string
}
http://nshipster.com/nsscanner/ is a good place to learn about NScanner for swift
EDIT: Here is the above translated to swift
var err: NSError? // Error handler
let url: NSURL = NSURL(string: "http://www.example.com") // NSURL, put your website URL in here
let string = NSString(contentsOfURL: url, encoding: NSUTF8StringEncoding, error: &err) // String will now hold your HTML
// Now use NScanner (See Link) to parse the HTML output
My swift is rusty. but this might help you. This is roughly translated but outlines exactly what you need