Tech Tip: Adding XML Comments in 4D Without Character Escaping
PRODUCT: 4D | VERSION: 20 R | PLATFORM: Mac & Win
Published On: October 20, 2025
When setting XML element values directly, 4D automatically escapes special characters like < and > to ensure validity, which can unintendedly convert comment syntax into plain text entities.
To insert a true XML comment node (e.g., <!--attachmentContent-->) without escaping, use DOM Append XML child node with the XML comment constant, as it creates a dedicated node type that preserves the content.
Project Method: Util_AddXMLComment
Usage and Verification
Build the XML structure, append the comment, and export to view the result:
To insert a true XML comment node (e.g., <!--attachmentContent-->) without escaping, use DOM Append XML child node with the XML comment constant, as it creates a dedicated node type that preserves the content.
Project Method: Util_AddXMLComment
| #DECLARE($elementRef : Text; $commentText : Text)->$commentRef : Text $commentRef:=DOM Append XML child node($elementRef; XML comment; $commentText) |
Usage and Verification
Build the XML structure, append the comment, and export to view the result:
| $docRef:=DOM Create XML Ref("root") $elemRef:=DOM Create XML element($docRef; "com:attachmentContent") $commentRef:=Util_AddXMLComment($elemRef; "attachmentContent") DOM EXPORT TO VAR($docRef; $xmlText) ALERT($xmlText) DOM CLOSE XML($docRef) |