Skip to main content

TIdText

TIdText = class(TIdMessagePart)

Example​

procedure PopulateTextPart(const Part: TIdText);
begin
  Part.ContentType := 'text/plain; charset="utf-8"';
  Part.Body.Clear;
  Part.Body.Add('Source-reviewed example text.');
end;

Usage​

TIdText represents a text MIME part in a message. Use its mutable Body lines for the text content and its MIME properties to describe the content type and encoding.

Additional Technical Info​

TIdText is the concrete text descendant of TIdMessagePart. Its PartType returns mptText, and it adds an owned Body line list plus IsBodyEncodingRequired.

Normal instances are owned by TIdMessage.MessageParts; references are borrowed. The constructor is not registered as a class-local Code Library entry, so use a part supplied/created by the surrounding Velox mail API. The object destroys its internal body when the part is destroyed.

Body and metadata​

Body is a TStringList exposed as TStrings. The returned list is live and mutable. Its strings are Unicode; default line-break behavior comes from Delphi TStrings. Duplicates are permitted and order is significant.

The property setter copies through Assign into the existing owned list. It never adopts/frees the supplied list. Self-assignment is destructive because current Delphi TStrings.Assign clears the destination before enumerating the source; Part.Body := Part.Body empties it.

Inherited ContentType, CharSet and ContentTransfer are metadata only. Changing them does not convert Body. Keep text, charset label and transfer encoder consistent.

Native Assign copies Body, then inherited headers/fields. It does not copy parent linkage or encoded flag. Copying can clear/partially populate the destination if an error occurs.

Encoding indicator limits​

IsBodyEncodingRequired scans only for UTF-16 code units above 127. It ignores ASCII controls, line length, transport capabilities and the selected ContentTransfer. It is a narrow non-ASCII test, not a complete MIME encoding decision.

Body edits, metadata edits and encoding are mutable/non-transactional and not thread-safe. Large bodies reside fully in memory; line operations and assignment allocate proportional to text size.

The source-reviewed example mutates an already supplied part and sends nothing.

External references

Created 2026-07-15