Assembler assembles a new document from many input documents. Assembler will retain the document being assembled. Input documents will be inserted into the assembled document at positions identified by the last <cx:append> control document received on the command port. The assembled document will be sent to the output port upon receipt of a signal on the send pin or receipt of a <cx:send> control document on the command port. The assembled document is cleared thereby discarding the assembled document upon receipt of a signal on the cleared pin or receipt of a <cx:clear> document on the command port.
A <cx:append> control document identifies the insertion point within the assembled document where new documents will be inserted. The insertion point is defined by an at attribute whose value is xpath expression. An at attribute value of "/" must be used to insert the initial document.
For further information on XPath/XSL expressions, see XSL references.