Objective-C

Convert Inline Data-URL Images to Related Parts

Demonstrates the Chilkat Email.ConvertInlineImages method, which converts images embedded inline within HTML (as base64 data URLs) into multipart/related MIME parts referenced from the HTML by cid:. This example sets an HTML body containing a data-URL image and converts it.

Background: HTML can embed an image two ways: as a data: URL (the base64 bytes sit right in the src attribute) or as a related part referenced by cid:. Many email clients don't render data: URLs for security reasons, so converting them to proper multipart/related parts — the traditional email way to embed images — greatly improves how reliably the images display.

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Objective-C

#import <CkoEmail.h>

BOOL success = NO;

//  Demonstrates the ConvertInlineImages method, which converts images embedded inline within
//  HTML (as base64 data URLs) into multipart/related MIME parts referenced from the HTML by
//  CID.

CkoEmail *email = [[CkoEmail alloc] init];
email.Subject = @"Convert inline images";

//  An HTML body with a base64 data-URL image (a 1x1 PNG).
[email SetHtmlBody: @"<html><body><img src=\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg==\"/></body></html>"];

NSLog(@"%@%d",@"NumRelatedItems before = ",[email.NumRelatedItems intValue]);

//  Convert the inline data-URL image(s) to multipart/related parts referenced by CID.

success = [email ConvertInlineImages];
if (success == NO) {
    NSLog(@"%@",email.LastErrorText);
    return true;
}

NSLog(@"%@%d",@"NumRelatedItems after = ",[email.NumRelatedItems intValue]);