Right now users have to two ways to send data to my application: upload a CSV file via browser, or via our API.
It would dramatically reduce duplication to use the API in both instances. Is there a way they could use the existing upload form, but instead of storing the CSV on the server, it would be processed via Javascript and sent to the API?
The solution would unfortunately have to be IE6 compatible.
There is no way to do this with IE6 (and in my opinion there is no reason to even try this).
Possible workarounds:
Embed the uploadform into a iframe (ugly)
Use a FlashPlayer 9+/JavaApplet to perform the upload (requires plugin), but this also gives you the possibility to process the data before sending it.
Unfortunately, no, this is not possible with IE6. Reading local files is possible in HTML5, but IE has a long way to go...
Also- it is not required to store the CSV on the server. You can process the CSV dynamically in a servlet and use the API to store the data without storing the CSV on the server.
Related
I have a JS blob of WAV Data which I need to convert to FLAC data which I need to send an AJAX request to my localhost Django server where I want to use the Google Speech API.
The important thing here is that I don't want to store any kind of audio data anywhere on the server (So I think I should refrain from using commands which include "input.wav" and "output.flac")
I tried using pySoX but didn't know how to use without providing the paths of input and output files.
I am open to any other strategies as I don't know how this is done conventionally.
I am working on a file upload system which will store individual parts of large files on more than one server. So the distribution of a 1GB file will look something like this:
Server 1: 0-128MB
Server 2: 128MB-256MB
Server 2: 256MB-384MB
... etc
The intention of this is to allow for redundancy (each part will exist on more than one server), security (no one server has access to the entire file), and cost (bandwidth expenses are distributed).
I am curious if anyone has an opinion on how I might be able to "trick" web browsers into downloading the various parts all in one link.
What I had in mind was something like:
Browser is linked to Server 1, which provides a content-size of the full file
Once 128MB is served, Server 1 will intentionally close the connection
Hopefully, the browser will try to restart the download, requesting Server 1
Server 1 provides a 3XX redirect to Server 2
Browser continues downloading from Server 2
I don't know for certain that my example works, as I haven't tested it yet. I was curious if there were other solutions someone might have?
I'd like to make the whole process as easy as possible (ideally requiring no work beyond a simple download). I don't want the users to have to use another program (ie: cat'ing the files together). I'd also like to not use a proxy server, since it would incur extra bandwidth costs.
As far as I'm aware, there is no javascript solution for writing a file, if there was one, that would be great.
AFAIK this is not possible by using the HTTP protocol. You can probably use a custom browser extension but it would depend on the browser. Another alternative is to create a Java applet that would download the file from different servers. The applet can accept the URLs to the different servers as parameters.
To save the generated file:
https://stackoverflow.com/a/4551467/329062
That solution stores the file in memory though, so it won't work with very large files.
You can download the partial files into a JS variable using JSONP. That will also let you get around the same-origin policy.
Javascripts security model will only allow you to access data from the same origin where the Javascript came from - i.e. not multiple servers.
If you are going to have the file bits on multiple servers, you will need the user to load the web page, fetch the bit and then finally stick the bits together in the correct order. If you can manage to get all your users to do this (correctly), you are a better man than I.
It's possible to do in modern browsers over standard HTTP.
You can use XHR2 with CORS to download file chunks as ArrayBuffers and then merge them using Blob constructor and use createObjectURL to send merged file to the user.
However, I suspect that browsers will store these objects in RAM, so it's probably a bad idea to use it for large files.
I have a series of JSON Objects I want to save locally on my server. I am attempting to avoid any server-side script like PHP as required per demand of whats being built. I know its a security risk, but that in this case is not a particular worry. So that said is it possible to actually write to a file and or get its contents via javascript with or without the help of a lib such as jquery?
I should mention I am attempting to avoid ActiveX as I know this is an IE only feature and the software we are developing is planned to be Cross Browser supported
So that said is it possible to actually write to a file and or get its contents via javascript with or without the help of a lib such as jquery?
Nope. You will need something running on server side that can receive your JavaScript input and write it to the server.
Internet Explorer's proprietary file writing functionality is for writing local (client-side) files only.
You can read a file using ajax, but without a server side language you cannot write a file to the server.
https://developer.mozilla.org/en/ajax
No. Javascript runs on the client. You need server-side code to access the server's file system.
Client-side JavaScript can only send data to a server, there's no way for it to tell the server what to do with the data.
To save data to a file or db on a server, you'll require a server-side script of some sort (could be server-side JS with Node.js). If all you need is persistent data, you could store some JSON strings in localStorage or in cookies as needed. They wouldn't be shareable that way though.
Yes, you can use AJAX requests in JavaScript without using jQuery. However, jQuery will save you an ungodly amount of time and cross-browser testing.
But, as others have already said, you can't write server files without server code.
I'm looking for a way to select and upload multiple files to Amazon S3, something in the vein of Uploadify, but with the following constraints :
No flash or HTML 5 - but AJAX and iframe tricks are allowed.
Multiple selection must happen in a single dialog.
Files must be sent directly to Amazon (there is no intermediary server to handle them).
Also, Amazon S3 does not allow uploading multiple files in a single request, so this means every file will have to be sent with a distinct request to a distinct URL, so I need to specify what those URLs will be.
Are any components around that might do this, or any known techniques I could leverage to build my own? Thank you.
Plain HTML file uploads are limited to one file at a time.
Javascript is restricted from accessing the user's file system, and must depend on the HTML file upload mechanism.
Consequently, we are left only with the complex options such as Flash, Java applets, or browser plugins. If they are not acceptable, you will not be able to support multiple file uploads.
I had a discussion with my colleague about Flash security. We're in the phase of planning some things for our web project that is using Flash plugin to display content. We need to dynamically pull settings for the Flash application from the server, using JSON.
Proposal that I offered was that we should save an extra HTTP request to pull the data file after the plugin is loaded and embed the JSON directly in the page containing the Flash plugin. Flash would fire a Javascript function that'd return the deserialized JSON data to it.
My colleague opposed this proposal with significant "security concerns".
I believe that there's literally zero difference between these two approaches besides the fact that his approach requires additional HTTP request. All of this is client/server and client should never be trusted. If I want to change the data that is in the JSON query, I can do that in both cases. File pull is little more difficult to hack though, but possible with custom HTTP proxy.
What are your thoughts?
There is no difference. Both can be fabricated.
if you really care that much about delivering original settings to the .swf:
don't use http - httpFox is a brilliant plugin - use a server that supports RTMP/RTMPE and NetConnection.call() to retrieve the data.
create an algorithm for validating original json so that your app won't work if the config doesn't pass the test.
after the config is loaded your swf might check the values with the server (not all at a time) and throw an error if something goes wrong