PowerBuilder

Save an Email to a Temporary MHT File

Demonstrates the Chilkat Email.CreateTempMht method, which prepares the email for display in a web browser and saves it as a temporary MHT file, returning the path that was written. If the filename argument is empty, Chilkat chooses a temporary filename.

To make the message viewable as a standalone web page, the method transforms it: all attachments are dropped; if the email has both HTML and plain-text alternatives, the plain-text alternative is dropped; and if the email has only a plain-text body, it is converted to HTML. This example loads an HTML email and creates the temporary MHT.

Background: MHT (MIME HTML) is a single-file web-page-archive format — it packs an HTML document together with its images and style sheets into one file, which is essentially what an HTML email already is. Because a Windows WebBrowser control can navigate directly to an .mht file, writing the message out as MHT is a quick way to render a received email, inline images and all, inside a desktop application. The transformations (dropping attachments, keeping just the HTML representation) ensure the result is a clean, self-contained page. For unpacking to loose files served by a web application instead, see AspUnpack.

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integer li_rc
integer li_Success
oleobject loo_Email
string ls_MhtPath

li_Success = 0

//  Demonstrates the CreateTempMht method, which prepares the email for viewing in a browser
//  and saves it as a temporary MHT (MIME HTML) file, returning the file path.
//  
//  To produce browser-viewable output, CreateTempMht transforms the message: it drops all
//  attachments; if the email has both HTML and plain-text alternatives it drops the
//  plain-text alternative; and if the email has only a plain-text body it converts that
//  body to HTML.  Passing an empty filename lets Chilkat choose a temporary filename.

loo_Email = create oleobject
li_rc = loo_Email.ConnectToNewObject("Chilkat.Email")
if li_rc < 0 then
    destroy loo_Email
    MessageBox("Error","Connecting to COM object failed")
    return
end if

li_Success = loo_Email.LoadEml("qa_data/eml/html_with_images.eml")
if li_Success = 0 then
    Write-Debug loo_Email.LastErrorText
    destroy loo_Email
    return
end if

//  Transform the email for browser display and save it as a temporary MHT file
//  (empty filename = auto-generated temp file).
ls_MhtPath = loo_Email.CreateTempMht("")

Write-Debug "Temporary MHT file: " + ls_MhtPath

//  Note: The path "qa_data/..." is a relative local filesystem path,
//  relative to the current working directory of the running application.


destroy loo_Email