Zig Requires Chilkat v11.0.0+

Create Binary MIME

See more MIME Examples

Demonstrates how to create and save a multipart/mixed MIME document where the parts (a JPG and a PDF) are NOT base64 encoded, but are instead binary. Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main() !void {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    const mime = try chilkat.Mime.init();
    defer mime.deinit();

    mime.setBodyFromPlainText("This is the plain text body.") catch {};
    mime.convertToMultipartMixed() catch {};
    mime.appendPartFromFile("qa_data/jpg/penguins.jpg") catch {};
    mime.appendPartFromFile("qa_data/pdf/fishing.pdf") catch {};

    // At this point, when saved, the MIME bodies will be base64 encoded.
    mime.saveMime("qa_output/sample.txt") catch {};

    // We now have the following MIME where everything is base64 encoded:
    // The code that follows shows how to eliminate the base64 to make this binary MIME.

    //     Content-Type: multipart/mixed; boundary="------------000207060703080505060404"
    //
    //     --------------000207060703080505060404
    //     Content-Type: text/plain
    //     Content-Transfer-Encoding: 7bit
    //
    //     This is the plain text body.
    //     --------------000207060703080505060404
    //     Content-Disposition: attachment; filename="penguins.jpg"
    //     Content-Type: image/jpeg; name="penguins.jpg"
    //     Content-Transfer-Encoding: base64
    //
    //     /9j/4AAQSkZJRgABAgEAYABgAAD/7gAOQWRvYmUAZAAAAAAB/+ESCEV4aWYAAE1NACoAAAAIAAcB
    //     MgACAAAAFAAAAGIBOwACAAAABwAAAHZHRgADAAAAAQAEAABHSQADAAAAAQA/AACcnQABAAAADgAA
    //     ...
    //     800a1MlLipJHlyU9en7sqVPkBK+gBj+o+1E91Ld7iJk0pJDO5PmDk4FOGOHy6S3JW120W1uCJ5M0
    //     PBa54edOFAc8ePX/2Q==
    //
    //     --------------000207060703080505060404
    //     Content-Disposition: attachment; filename="fishing.pdf"
    //     Content-Type: application/pdf; name="fishing.pdf"
    //     Content-Transfer-Encoding: base64
    //
    //     JVBERi0xLjMKJcfsj6IKNSAwIG9iago8PC9MZW5ndGggNiAwIFIvRmlsdGVyIC9GbGF0ZURlY29k
    //     ZT4+CnN0cmVhbQp4nM1c288cNxVX09A0myq35tom7bSl8E1hp76P/YpASIiXlEg8tDwVKEJfilIe
    //     ...
    //     MDRGMT48OTlENkRFQzExQjkzNjA0Mjc1RUFCNzIyMjI4RjA0RjE+XQo+PgpzdGFydHhyZWYKMjk0
    //     MzY5CiUlRU9GCg==
    //
    //     --------------000207060703080505060404--
    //

    // To make it binary MIME (getting rid of the base64), set the Encoding property to "binary"
    // for the JPG and PDF parts.

    const jpg_part = try chilkat.Mime.init();
    defer jpg_part.deinit();
    mime.partAt(1, jpg_part) catch {};

    jpg_part.setEncoding("binary");

    const pdf_part = try chilkat.Mime.init();
    defer pdf_part.deinit();
    mime.partAt(2, pdf_part) catch {};

    pdf_part.setEncoding("binary");

    // Now save it.  If you try to view this MIME in a text editor,
    // the JPG and PDF parts will be garbled and unintelligible. That's because
    // the bytes do not represent characters.
    mime.saveMime("qa_output/sampleBinary.mim") catch {};

    // The MIME now contains this:

    //     Content-Type: multipart/mixed; boundary="------------000207060703080505060404"
    //
    //     --------------000207060703080505060404
    //     Content-Type: text/plain
    //     Content-Transfer-Encoding: 7bit
    //
    //     This is the plain text body.
    //     --------------000207060703080505060404
    //     Content-Disposition: attachment; filename="penguins.jpg"
    //     Content-Type: image/jpeg; name="penguins.jpg"
    //     Content-Transfer-Encoding: binary
    //
    //     <Binary Data Here>
    //
    //     --------------000207060703080505060404
    //     Content-Disposition: attachment; filename="fishing.pdf"
    //     Content-Type: application/pdf; name="fishing.pdf"
    //     Content-Transfer-Encoding: binary
    //
    //     <Binary Data Here>
    //
    //     --------------000207060703080505060404--
    //

    // Can we load this binary MIME into an Email object?
    const bin_data = try chilkat.BinData.init();
    defer bin_data.deinit();
    // Write the binary MIME into binData;
    mime.getMimeBd(bin_data) catch {};

    const email = try chilkat.Email.init();
    defer email.deinit();
    // Load the email from the binData.
    email.setFromMimeBd(bin_data) catch {};

    // Note: Many email clients may not be able to correctly process emails
    // using the binary encoding.  Thunderbird has trouble.  Windows Live Mail
    // worked OK.
    email.setSubject("Binary MIME Email");
    email.setFrom("admin@chilkatsoft.com");
    email.addTo("Chilkat", "support@chilkatsoft.com") catch {};
    email.saveEml("qa_output/binaryEmail.eml") catch {};

    // Chilkat does not recommend trying to use binary MIME for email.
    // Binary MIME is typically used in HTTP for uploads and downloads.
    //

    // Also, binary MIME is not representable in a string.
    // If we try to get the MIME as a string, then it must be encoded
    // using base64.

    // Chilkat automatically changes binary encodings to base64
    // when there's an attempt to get the MIME as a string.
    const sb = try chilkat.StringBuilder.init();
    defer sb.deinit();
    email.getMimeSb(sb) catch {};
    sb.writeFile("qa_output/email_fromSb.eml", "utf-8", false) catch {};

    // Likewise, if we try to get the MIME as a string from the Mime object,
    // it cannot contain non-character data in a binary encoding.  The binary
    // bytes MUST be in base64.  The act of trying to retrieve the MIME in string
    // format will force Chilkat to convert binary encodings (for non-text parts)
    // to base64.
    mime.getMimeSb(sb) catch {};
    sb.writeFile("qa_output/mime_fromSb.eml", "utf-8", false) catch {};

    // However, the above use of base64 is just for the purpose of making the MIME
    // string friendly.  If we save the MIME to a file, it's still binary:
    mime.saveMime("qa_output/mime_binary.mime") catch {};
}