Scala/Play gurus out there.
I'm trying to upload a file using AJAX, in Play 2.1 (RC1). For the client part I'm using eldarion/bootstrap-ajax and everything seems to be fine, except that the uploaded file is empty.
The front-end snippet:
...
<form action="#routes.Campaigns.upload" method="post" class="form ajax replaceable" data-replace=".replaceable">
<input type="file" name="picture">
<p><input class="btn" type="submit"></p>
</form>
...
Note that I had to use the explicit <form> tag instead of the #form helper, due to the fact that the required css class (data-replace) contains a dash, and therefore can not be used as a Symbol. But anyway. The called action in the controller looks like this:
def upload = Action(parse.temporaryFile) {
request =>
Logger.info("Trying to upload a file")
val resultString = try {
val file = new File("/tmp/picture")
request.body.moveTo(file, true)
"file has been uploaded"
} catch {
case e: Exception => "an error has occurred while uploading the file"
}
val jsonResponse = Json.toJson(
Map("html" -> Json.toJson("<p>" + resultString + "</p>")
)
)
Ok(jsonResponse)
}
I'm aware that as my development goes forward the file name should be more intelligently set, but for the moment being, /tmp/picture is for me as good a name as any other one.
The JSON response gets generated (with the "file has been uploaded" message within), and is sent back to the browser as the payload of the 200 response. The JSON is received and correctly used to modify the page (in this case, merely removing the very uploading form).
But the file, although appearing in the right moment and in the right place, is always empty:
larsson:tmp bruno$ ls -l /tmp/picture
-rw-r--r-- 1 bruno staff 0 7 Jan 03:07 /tmp/picture
That's specially strange, in my opinion, because the uploading code which uses a traditional multipart/form-data form, with no AJAX whatsoever, and an Action with parse.multipartFormData as a parameter, instead of parse.temporaryFile, works finely.
Any help will be very appreciated. Thanks in advance.
I don't know bootstrap-ajax, anyway if it hasn't dedicated support for uploading files via AJAX (and I didn't find any info about that possibility in its readme file) it will NOT send files with AJAX.
Reason: In standard JavaScript uploading files with AJAX is not possible due the security limits and there are some techniques to workaround this, mainly using iFrames, however I can't see nothing similar in the code of bootstrap-ajax so probably you need to modify it or use other solution.
Solution: There are some AJAX file uploaders, which works good with HTML5 ie. jQuery File Upload, which offers ajax upload, multi-file uploads, drag file to the drop zone etc.
In general HTML5 supports file uploads better than earlier versions of HTML, so you can build uploader easily without need of using additional plugins, take a look to this topic. As you can see it delivers possibilities to validate some data BEFORE the upload and also offers progress bars.
I'm currently trying to implement something like this and I got a first version working. This is how I do it:
In my Controller I define a method for uploading files. In my case I use Action.async since I save stuff to my MongoDB with reactivemongo. I have removed that code so that it do not complicate this example.
What I do in this example is that I upload a csv file, save it to disk and then produce the first row back as a string to the user. In real life the method produces a list back so that user is able to choose which column represent what an so on.
I use mighty csv for csv parsing. GREAT LIB!
Application:
def upload = Action.async(parse.multipartFormData) {
implicit request =>
val result = uploadForm.bindFromRequest().fold(
errorForm => Future(BadRequest(views.html.index(errorForm))),
form => {
import java.io.File
request.body.file("csvFile").map {
csv =>
val path = current.configuration.getString("csv.job.new.file.path").getOrElse("")
val name = DateTime.now().getMillis + ".csv"
csv.ref.moveTo(new File(path + name))
val settings = CSVReaderSettings.Standard(linesToSkip = form.linesToSkip)
val rows: Iterator[Array[String]] = CSVReader(path + name)(settings)
val firstRow = rows.next()
val test = firstRow match {
case xs if xs.size == 0 || xs.size == 1 => xs.mkString
case xs if xs.size > 1 => xs.mkString(", ")
}
Future(Ok(test))
}.getOrElse(Future(BadRequest("ahadasda")))
}
)
result
}
routes:
POST /upload #controllers.Application.upload
I use # before the controllers because I use DI with guice for my service classes.
Since we will use javascript for uploading we need to define our jsRoutes:
jsRoutes:
def javascriptRoutes = Action {
implicit request =>
import routes.javascript._
Ok(
Routes.javascriptRouter("jsRoutes")(
Application.upload
)
).as("text/javascript")
}
Remember to import in your template where you want to use the routes:
<script type="text/javascript" src="#routes.Application.javascriptRoutes"></script>
<script src="#routes.Assets.at("javascripts/app.js")#Messages("js.version")" type="text/javascript" ></script>
In my view template I have a regular helper form. There is some css style stuff I do to
change the looks and feel of the upload button and file chooser. But the input fields
are there.
index.scala.html:
<div class="csvContainer">
#helper.form(action = routes.Application.upload, 'enctype -> "multipart/form-data", 'id -> "csvUpload") {
#Messages("upload.row.skip")
#inputText(uploadForm("linesToSkip"), 'class -> "hidden")
<div style="position:relative;">
<div id="csvFile" style="position:absolute;">
#Messages("upload.choose")
</div>
<input id="uploadFile" type="file" name="csvFile" style="opacity:0; z-index:1;" onchange="document.getElementById('csvFile').innerHTML = this.value;" />
</div>
<p>
<input type="submit" value="#Messages("upload.submit")">
</p>
}
</div>
In app.js is where the ajax magic happens, remember I have not implemented any validation or cool html5 stuff yet as the progressbar and other handlers, described in besiors link.
I use regular JQuery.
app.js:
$('#uploadFile').change(function(){
var name = $(this).val().split("\\");
console.log(name[2]);
$('#csvFile').text(name[2]);
});
$('#csvFile').click(function(){
$('#uploadFile').click();
});
$("#csvUpload").submit(function(e) {
e.preventDefault();
var formData = new FormData();
formData.append('csvFile', $( '#uploadFile' )[0].files[0]);
formData.append('linesToSkip', $( "#linesToSkip").val());
jsRoutes.controllers.Application.upload().ajax({
data: formData,
processData: false,
contentType: false,
cache: false,
type: 'POST',
success: function(data){
alert(data);
}
});
});
I have removed a lot of code to simplify this example and I hope that I have not forgotten anything. Hope this helps!
I'm currently using project awesome to pop a form which asks for an account number.
I take the number and generate a csv file and send it to the browser:
string billcsv = "account_ref,line1,line2,line3"
var VIRFile = File(new System.Text.UTF8Encoding().GetBytes(billcsv), "text/csv", "billfor" + accnumber+ ".csv")
return Json(VIRFile);
I would like the end user to prompted to save the csv file but cannot figure out who to.
Should I create the CSV file on disk first then pass the url to the file to the success function and use window.open(url) or is it possible to use javascript to recreate the file from the json result?
Json Result:
{"FileContents":[65,99,99,111,117,110,116,95,82,69,70,44,73,78,86,79,73,67,69,95,84,89,80,69,44,73,78,86,79,73,67,69,95,82,69,70,44,81,84,89,95,79,82,68,69,82,44,83,69,82,86,73,67,69,95,84,69,88,84,44,85,78,73,84,95,80,82,73,67,69,44,83,69,82,86,73,67,69,95,65,77,79,85,78,84,13,10,114,114,114,44,73,110,118,111,105,99,101,44,86,73,82,49,48,50,44,49,44,83,116,97,114,83,104,105,112,32,32,79,110,101,13,10,44,76,79,65,32,45,32,32,109,116,114,115,13,10,44,71,82,84,32,45,71,84,44,48,44,48,44,48,13,10,114,114,114,44,73,110,118,111,105,99,101,44,86,73,82,49,48,50,44,50,44,66,111,97,116,32,84,114,97,110,115,102,101,114,115,32,72,105,114,101,32,67,104,97,114,103,101,44,50,53,48,46,48,48,44,53,48,48,46,48,48,13,10,114,114,114,44,73,110,118,111,105,99,101,44,86,73,82,49,48,50,44,51,44,66,101,114,116,104,105,110,103,32,32,82,70,65,32,47,32,77,111,68,44,51,53,48,46,48,48,44,49,48,53,48,46,48,48,13,10],"ContentType":"text/csv","FileDownloadName":"billfor123.csv"}
First of all don't use AJAX for downloading files. Use a normal form submission or an anchor pointing to the controller action which will serve the file. And then in the controller:
public ActionResult Download(string accnumber)
{
string billcsv = "account_ref,line1,line2,line3";
var data = Encoding.UTF8.GetBytes(billcsv);
string filename = "billfor" + accnumber + ".csv";
return File(data, "text/csv", filename);
}
Now in order to invoke this action and have the user be prompted for download simply create a link:
#Html.ActionLink("Download csv", "Download", new { accnumber = "123" })
or if you are using a form:
#Html.BeginForm("Download", "SomeController")
{
#Html.TextBox("accnumber")
<input type="submit" value="Download CSV" />
}
Submitting the form using AJAX has disadvantages. You shouldn't be doing this. I would rather use #Html.BeginForm() helper to generate the form and submit the data using button event.
Hope this helps