Lua

The MIME Content-Type Header Field

See more MIME Examples

Explains the ContentType property and the Content-Type header field including the various attributes that may be included. Lua

local chilkat = require("chilkat")

local success = false

-- Every part in a MIME messsage should include a Content-Type header field.
-- The Content-Type indicates the type of content contained in the MIME part.
-- For example: text/plain, image/jpeg, application/pdf, application/json, multipart/mixed, etc.

-- Multipart content types are those where the MIME part's body is composed of N inner MIME messages,
-- separated by a boundary string.
-- This is how MIME gets a nested, tree-like structure.  The most common multipart MIME types
-- are (for email related MIME) multipart/mixed, multipart/alternative, and multipart/related,
-- and for HTTP related MIME, it is multipart/form-data.

local mime = chilkat.Mime.new()

-- The Content-Type header field can be set or modified in two ways.
-- 1) By setting the ContentType, Micalg, Name, Charset, Boundary, or Protocol properties.
--    Setting the ContentType property sets the primary value (such as "text/plain") of the header field.
--    Each of the other properties listed above will replace or add a particular attribute value.

-- 2) By setting the entire contents of the ContentType header with the SetHeaderField method.
--    This updates each of the Content-Type related properties.

-- For example:
mime.content_type = "text/plain"
mime.charset = "utf-8"

-- The Content-Type header field contains this:
--     Content-Type: text/plain; charset=utf-8
print(mime:get_entire_head())
print("-")

mime:set_header_field("Content-Type", "image/jpeg; name=\"kitty.jpg\"")
-- The Content-Type header field now contains this:
--     Content-Type: image/jpeg; name="kitty.jpg"
print(mime:get_entire_head())
print("-")

-- Notice how the properties have been updated:
print("ContentType property: " .. mime.content_type)
print("Charset property: " .. mime.charset)
print("Name property: " .. mime.name)
print("-")

-- To change a particular attribute value, set the property.
mime.name = "doggy.jpg"
print(mime:get_entire_head())
print("-")

-- To remove an attribute value from the Content-Type header,
-- set the property to an empty string.
mime.name = ""
print(mime:get_entire_head())
print("-")