Alfresco - submitting dynamic forms to upload.post with javascript - alfresco

Question

I'm encountering issues with a dashlet that I'm trying to develop for Alfresco. It's a simple drag and drop file upload dashlet using HTML 5's drag and drop and file APIs. For the drop event listener, I call the following function which is seemingly the cause of all the problems:
function handleFileSelect(evt) {
var files = evt.target.files || evt.dataTransfer.files,
tmpForm, tmpDest, tmpMeta, tmpType, tmpName, tmpData;
dropZone.className = "can-drop";
evt.stopPropagation();
evt.preventDefault();
for (var i=0,f;f=files[i];i++) {
tmpForm = document.createElement('form');
tmpDest = document.createElement('input');
tmpDest.setAttribute('type', 'text');
tmpDest.setAttribute('name', 'destination');
tmpDest.setAttribute('value', destination);
tmpForm.appendChild(tmpDest);
tmpMeta = document.createElement('input');
tmpMeta.setAttribute('type', 'text');
tmpMeta.setAttribute('name', 'mandatoryMetadata');
tmpMeta.setAttribute('value', window.metadataButton.value);
tmpForm.appendChild(tmpMeta);
tmpType = document.createElement('input');
tmpType.setAttribute('type', 'text');
tmpType.setAttribute('name', 'contenttype');
tmpType.setAttribute('value', "my:document");
tmpForm.appendChild(tmpType);
tmpName = document.createElement('input');
tmpName.setAttribute('type', 'text');
tmpName.setAttribute('name', 'filename');
tmpName.setAttribute('value', f.name);
tmpForm.appendChild(tmpName);
tmpData = document.createElement('input');
tmpData.setAttribute('type', 'file');
tmpData.setAttribute('name', 'filedata');
tmpData.setAttribute('value', f);
tmpForm.appendChild(tmpData);
Alfresco.util.Ajax.request({
url: Alfresco.constants.PROXY_URI_RELATIVE + "api/upload",
method: 'POST',
dataForm: tmpForm,
successCallback: {
fn: function(response) {
console.log("SUCCESS!!");
console.dir(response);
},
scope: this
},
failureCallback: {
fn: function(response) {
console.log("FAILED!!");
console.dir(response);
},
scope: this
}
});
}
}
The server responds with a 500, and if I turn on debug level logging for web scripts, upload.post returns with:
DEBUG [repo.jscript.ScriptLogger] ReferenceError: "formdata" is not defined.
Which, to me at least, indicates that the form above isn't getting submitted properly (if at all). When digging through it all with Chrome dev tools, I notice that that request payload looks drastically different from something such as a REST client. The above code results in the request using Content-Type: application/x-www-form-urlencoded whereas using a REST client, or Alfresco Share's standard uploader(s) are using Content-Type: multipart/form-data. If I need to submit the form using multipart/form-data, what is the easiest way to write out the request body (with the boundaries, Content-Disposition's, etc...) to include the file being uploaded?

Answer 1

I ditched the idea of creating a form HTML Element through javascript, and assume that if a browser supports the File API, and the Drag and Drop API, that they will likely also support the XMLHttpRequest2 API. As per HTML5 File Upload to Java Servlet, The above code now reads:
function handleFileSelect(evt) {
var files = evt.target.files || evt.dataTransfer.files,
xhr = new XMLHttpRequest();
dropZone.className = "can-drop";
evt.stopPropagation();
evt.preventDefault();
for (var i=0,f;f=files[i];i++) {
formData = new FormData();
formData.append('destination', destination);
formData.append('mandatoryMetadata', window.metadataButton.value);
formData.append('contenttype', "my:document");
formData.append('filename', f.name);
formData.append('filedata', f);
formData.append('overwrite', false);
xhr.open("POST", Alfresco.constants.PROXY_URI_RELATIVE + "api/upload");
xhr.send(formData);
}
}
with the necessary event listeners to be added later. It would seem that the Alfresco AJAX methods that come stock and standard heavily modify the underlying requests being made, making it very difficult for one to simply send a FormData() object.