AddItems
procedure AddItems(AList: TIdEMailAddressList);
Example
procedure MergeRecipients(const Target, Source: TIdEMailAddressList);
begin
if Target <> Source then
Target.AddItems(Source);
end;
Usage
AddItems appends field copies of every source address item, treating nil as a no-op and self-copy as duplication of the original entries.
Additional Technical Info
AddItems appends a new owned item for each entry present in AList at loop start, then calls Assign to copy its raw Address and Name fields.
| Parameter | Meaning |
|---|---|
AList | Borrowed source list. Nil is accepted and produces no change. |
The method does not clear the destination. Existing entries remain before the appended copies. Source item objects are not transferred, reparented or retained; later edits to either list are independent.
Copying Address and Name directly preserves those two Strings more faithfully than round-tripping through formatted Text. Derived User, Domain and Text naturally reflect the copied fields.
Passing the destination itself is permitted by the exact loop behavior. Delphi evaluates the original upper bound before iteration, so the method appends one copy of each originally present item and doubles Count; it does not loop forever. This is rarely intentional and can duplicate every recipient, so guard as shown.
The operation is non-transactional. Each iteration adds a blank destination item before assigning it. If allocation, collection notification or assignment raises, previous copies remain and the current newly added item can remain blank/partial. Nil is the only explicit no-op case.
Time and additional storage are O(n) in source count and copied text length. A very large or self-copied list can expand message headers and recipients substantially. Neither list may be modified concurrently; source deletion/reordering during the loop is unsupported.
The source-reviewed example prevents accidental self-duplication. It was not executed and sends no recipients.
External references
- Indy upstream:
TIdEMailAddressList.AddItems- append-and-assign implementation. - Embarcadero DocWiki:
System.Classes.TPersistent.Assign- Delphi assignment protocol used by each item. - Free Pascal:
TPersistent.Assign- compatible assignment context; current Indy override defines the copied fields.