SOAP Attachments

by Tom Welsh

No matter how trivial any aspect of Web services may seem, it usually has hidden depths. Thus when I sat down to write this issue, my outline allocated a couple of pages to the subject of SOAP attachments; I meant to devote the remaining space to several other initiatives. Well, "The best-laid schemes o' Mice an' Men/Gang aft agley." By the time I had looked into SOAP with Attachments, MIME, WS-Attachments, DIME, PASwA, MTOM, and XOP¹ -- not to mention the mysterious Infoset -- I found myself struggling to pack everything I had to say into the space available. So this issue of WSS is devoted to the question of how non-XML data can best be attached to SOAP messages and the implications of that not-so-simple question.