Swift

Enumerate the Header Fields of an Email

Demonstrates the read-only Chilkat Email.NumHeaderFields property together with GetHeaderFieldName and GetHeaderFieldValue to enumerate every header field. Indexing is zero-based, so fields run from 0 to NumHeaderFields - 1. Repeated header fields (a field name that appears more than once) are counted separately. This example builds a small email and prints each header field.

Background: A header field is a single Name: value line at the top of a MIME message. The same field name can legitimately appear multiple times — for example, a message can carry several Received lines, one added by each mail server it passed through. That is why enumerating by index (rather than looking up by name) matters: it lets you see every occurrence in the order it appears.

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Swift


func chilkatTest() {
    //  Demonstrates the read-only Email.NumHeaderFields property and enumerating each
    //  header field by zero-based index using GetHeaderFieldName and GetHeaderFieldValue.

    let email = CkoEmail()!
    email.subject = "Header field enumeration"
    email.from = "mary@example.com"
    email.add(to: "Joe", emailAddress: "joe@example.com")

    var n: Int = email.numHeaderFields.intValue
    print("NumHeaderFields = \(n)")

    var i: Int
    for i = 0; i <= n - 1; i++ {
        print("\(email.getHeaderFieldName(index: i)!): \(email.getHeaderFieldValue(index: i)!)")
    }


}