javascript - breezejs: calling savecChanges for a classic ODATA service fails

Question

I'm trying to save an Entity that was loaded using a classic WEBAPI ODATA service.

When saveChanges is called on the client side, the modified entity is found and then the code goes into ′createChangeRequests′ and because the entityState is modified it goes into the function :

 function updateDeleteMergeRequest(request, aspect, prefix) {
    var extraMetadata = aspect.extraMetadata;
    var uri = extraMetadata.uri;
    if (__stringStartsWith(uri, prefix)) {
        uri = uri.substring(prefix.length);
    }
    request.requestUri = uri;
    if (extraMetadata.etag) {
        request.headers["If-Match"] = extraMetadata.etag;
    }
}

However it raises an exception on the second line because extraMetadata is null. Where is this supposed to come from ? The property extraMetadata does not even exist on 'aspect'....

breeze does have metadata of my model since I can load entities. It's just that I cannot save.

Answer 1

line 13318(breeze.debug.js):

    function mergeEntity(node, mappingContext, meta) {
      node._$meta = meta;
      meta.extra = node.__metadata;//added
      var em = mappingContext.entityManager;