(Objective-C) Download Web Page to MHT and Extract Images (all in memory)

Downloads a web page to an MHT archive (in memory) and then extracts each image to a byte array in memory.

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#import <NSString.h>
#import <CkoMht.h>
#import <CkoEmail.h>
#import <CkoStringBuilder.h>

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Note: This URL exists at the time of writing and testing this example (on 12-June-2020)
// However, it will surely not continue to exist for very long.
// You should choose a different URL.  (Any web page with images will do.)
NSString *url = @"https://www.fendi.com/it/abbigliamento-uomo/cravatta-fxc160a3nwf0qg2";

CkoMht *mht = [[CkoMht alloc] init];

// Downloads to an MHT string.
// MHT is just MIME, which is the same format as an email but with different semantics.
NSString *mhtStr = [mht GetMHT: url];
if (mht.LastMethodSuccess == NO) {
    NSLog(@"%@",mht.LastErrorText);
    return;
}

// We can still treat the MHT MIME as an email and iterate over the "related items".
CkoEmail *email = [[CkoEmail alloc] init];
BOOL success = [email SetFromMimeText: mhtStr];
if (success == NO) {
    NSLog(@"%@",email.LastErrorText);
    return;
}

int numRelatedItems = [email.NumRelatedItems intValue];
int i = 0;
CkoStringBuilder *sbContentType = [[CkoStringBuilder alloc] init];
while (i < numRelatedItems) {
    [sbContentType SetString: [email GetRelatedContentType: [NSNumber numberWithInt: i]]];
    NSLog(@"%@%@",@"Content-Type: ",[sbContentType GetAsString]);

    if ([sbContentType StartsWith: @"image/" caseSensitive: NO] == YES) {
        // We have an image.
        // Get the image data.
        NSData imageData = [email GetRelatedData: [NSNumber numberWithInt: i]];

        // Do what you need with the image data..
    }

    i = i + 1;
}