Introduction to Sending Emails with Embedded Images from an iPhone App
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In this article, we’ll explore how to send emails from an iPhone app that contain embedded images. This involves using the mailto URL scheme to open the native email client and adding an image to the email body.
Background: Understanding the mailto URL Scheme
The mailto URL scheme is used to send emails on mobile devices. When you use this scheme, your app opens the user’s default email client, allowing them to compose a new email with the specified recipient and subject.
However, there are some limitations to using the mailto scheme alone. For example, it doesn’t allow for sending attachments or formatting text in a meaningful way. To overcome these limitations, we’ll need to use HTML and CSS to format our email body and add an image.
Understanding URL Encoding
When working with URLs, it’s essential to understand how to encode certain characters. In particular, the mailto scheme requires special handling for certain characters like quotation marks (%22), less-than signs (%3C), and greater-than signs (%3E).
For example, if you want to send an email with a subject that contains these characters, you’ll need to URL encode them first. This will ensure that the correct characters are displayed in the email.
Understanding HTML Email Bodies
An HTML email body allows for more formatting options than plain text emails. In this article, we’ll use HTML to format our email body and add an embedded image.
iPhone App Development Considerations
When building an iPhone app that sends emails with embedded images, there are a few things to keep in mind:
- The
mailtoscheme only works when the user has the native email client installed on their device. - The email client may not display your app’s logo or branding in the recipient’s inbox.
- The email client may also not support all of your desired HTML formatting.
Example Code: Sending an Email with an Embedded Image
Here’s an example of how to send an email from an iPhone app using the mailto scheme and HTML:
NSString *url = [NSString stringWithFormat:@"mailto:email@example.com?subject=Check%20Out%20This%20Faux%20Screen&body=<html><body><img src=\"http://www.sample.com/FauxFoneServer/screenShot/getScreenByID?cur=%@\"/>The%20awesome%20person%20who%20sent%20you%20this%20email%20thinks%20you%20should%20visit%20http://www.fauxscreen.com"/%3E%3C%2Fbody>%3C%2Fhtml>", [ScreenShotsAppDelegate sharedDelegate].viewController.curImage.imageID];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:url]];
Explanation of the Code
In this example, we’re using the mailto URL scheme to send an email with a subject and body. The body parameter is set to HTML, which allows us to add an image using the <img> tag.
We’re also using URL encoding for certain characters like quotation marks (%22) and less-than signs (%3C). This ensures that these characters are displayed correctly in the email.
The [ScreenShotsAppDelegate sharedDelegate].viewController.curImage.imageID part is used to determine which image ID to use for the embedded image. You can replace this with your own logic to get the correct image ID.
Example Use Case: Embedding an Image from a Server
If you’re hosting images on a server, you’ll need to modify the code above to include the full URL of the image. Here’s an updated example:
NSString *url = [NSString stringWithFormat:@"mailto:email@example.com?subject=Check%20Out%20This%20Faux%20Screen&body=<html><body><img src=\"http://www.sample.com/FauxFoneServer/screenShot/getScreenByID?cur=%@\"/>The%20awesome%20person%20who%20sent%20you%20this%20email%20thinks%20you%20should%20visit%20http://www.fauxscreen.com"/%3E%3C%2Fbody>%3C%2Fhtml>", [ScreenShotsAppDelegate sharedDelegate].viewController.curImage.imageID];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:url]];
Note that we’re using a relative URL for the image source. If you want to use an absolute URL, replace http://www.sample.com/FauxFoneServer/ with your server’s full URL.
Conclusion
Sending emails from an iPhone app that contain embedded images is a bit more complex than it seems at first glance. However, by using the mailto URL scheme and HTML, you can create beautifully formatted emails with embedded images. Just remember to handle certain characters like quotation marks and less-than signs using URL encoding.
By following these steps and examples, you should be able to send emails from your iPhone app that contain embedded images. Happy coding!
Last modified on 2024-06-23