Both should work.
(I just tested and it really seems that both work...)
NB : take care to correctly encode your data to avoid unexpected characters. For instance, have a look at htmlEncodeJson() in projeqtor code
Here are two exemples that works with POST action :
{"identifier":"id", "items":[{"id":"1", "reference":"001-001-INC-1", "name":"OK I CHNAGED NAME", "idTicketType":"16", "nameTicketType":"Incident", "idProject":"2", "nameProject":"project one - maintenance", "externalReference":"", "idUrgency":"2", "nameUrgency":"Urgent", "creationDateTime":"2011-09-01 12:00:00", "idUser":"1", "nameUser":"admin", "idContact":"", "nameContact":"", "originType":"", "originId":"", "refName":"bug: it does not work DOES IT ?", "idTicket":"", "nameTicket":"", "idContext1":"", "nameContext1":"", "idContext2":"", "nameContext2":"", "idContext3":"", "nameContext3":"", "idProduct":"", "nameProduct":"", "idComponent":"", "nameComponent":"", "idOriginalProductVersion":"1", "nameOriginalProductVersion":"wa V1.0", "idOriginalComponentVersion":"", "nameOriginalComponentVersion":"", "description":"<div>test pmlouf</div>", "idActivity":"", "nameActivity":"", "idStatus":"8", "nameStatus":"re-opened", "idResolution":"", "nameResolution":"", "idResource":"3", "nameResource":"project manager", "idCriticality":"1", "nameCriticality":"Low", "idPriority":"1", "namePriority":"Low priority", "initialDueDateTime":"2011-09-02 18:00:00", "actualDueDateTime":"2011-09-09 18:30:00", "plannedWork":"0.00000", "realWork":"0.00000", "leftWork":"0.00000", "handled":"0", "handledDateTime":"", "done":"0", "doneDateTime":"", "solved":"0", "idle":"0", "idleDateTime":"", "cancelled":"0", "idTargetProductVersion":"", "nameTargetProductVersion":"", "idTargetComponentVersion":"", "nameTargetComponentVersion":"", "result":"<div>dans leau </div>"}] }
{"apiResult":"OK", "apiResultMessage":"Ticket #1 updated", "id":"1", "reference":"001-001-INC-1", "name":"OK I CHANGED AGAIN", "idTicketType":"16", "nameTicketType":"Incident", "idProject":"2", "nameProject":"project one - maintenance", "externalReference":"", "idUrgency":"2", "nameUrgency":"Urgent", "creationDateTime":"2011-09-01 12:00:00", "idUser":"1", "nameUser":"admin", "idContact":"", "nameContact":"", "originType":"", "originId":"", "refName":"OK I CHNAGED NAME", "idTicket":"", "nameTicket":"", "idContext1":"", "nameContext1":"", "idContext2":"", "nameContext2":"", "idContext3":"", "nameContext3":"", "idProduct":"", "nameProduct":"", "idComponent":"", "nameComponent":"", "idOriginalProductVersion":"1", "nameOriginalProductVersion":"wa V1.0", "idOriginalComponentVersion":"", "nameOriginalComponentVersion":"", "description":"<div>test pmlouf</div>", "idActivity":"", "nameActivity":"", "idStatus":"8", "nameStatus":"re-opened", "idResolution":"", "nameResolution":"", "idResource":"3", "nameResource":"project manager", "idCriticality":"1", "nameCriticality":"Low", "idPriority":"1", "namePriority":"Low priority", "initialDueDateTime":"2011-09-02 18:00:00", "actualDueDateTime":"2011-09-09 18:30:00", "plannedWork":"0.00000", "realWork":"0.00000", "leftWork":"0.00000", "handled":"0", "handledDateTime":"", "done":"0", "doneDateTime":"", "solved":"0", "idle":"0", "idleDateTime":"", "cancelled":"0", "idTargetProductVersion":"", "nameTargetProductVersion":"", "idTargetComponentVersion":"", "nameTargetComponentVersion":"", "result":"<div>dans leau </div>"}