I want to write to a text file using javascript. I know that it is possible but there are some problems.
I am running a javascript program that calculates the location of an object (its latitude & longitude) which changes every 5 seconds; i want to write this information to a text file. The javascript program will soon run on a server and I'll use the information written to the text file to communicate with an Android app on my phone.
So, my question really is:
How can it be done properly?
I know that there may be some permission issues but considering it won't be online and available to others will it be a problem and, if it is, should I go with PHP to do what I want? I know ASP is more Microsoft orientated and I work with a Mac so PHP would be the preference here.
When writing a file, is it possible to write to an existing file or does the process simply destroy and recreate the same file?
I would use PHP
http://www.php.net/
This has a good code example:
http://www.tizag.com/phpT/filewrite.php
Also, you can make the request using jQuery's AJAX function, this will allow to effectively run this code from javascript:
http://api.jquery.com/jQuery.ajax/
Using the latest HTML5 Javascript, you can use the FileSystem APIs to read/write/append to text files. This is a good tutorial here : Exploring the FileSystem APIs.
Related
I have created an interactive quiz using html and javascript which will be run on a touchscreen at an event and I need to write the results to a local csv file (so no internet connection). It needs to write to an already existing file, so it cannot be done where the data is stored locally and a download link is generated through the browser.
How would I go about doing this? All methods I have found are either unreliable or no longer supported. The browser I am using is Chrome, so it does not need to be cross-browser compatible.
Can anybody help or point me in the right direction please?
Install a web server.
Point the browser at http://localhost.
Send the data to the server using Ajax or a form submission.
Process the data (including storing it in a file) using the server side language of your choice.
When javascript is used only in the client-side cannot write data as you want.
Follow the #Quentin recommendation about install some web server, as apache using php for instance(It is pretty straight forward!). I also recommend you to create restFull methods to do it with jquery calls from the client side, it is easy to find many examples in the internet and quicky...
If you want something more easy you could work with html post using forms in php, the most easy way to do it.
I want to convert some web pages with javascript to plain html, and I found there several ways(pls tell me if I'm wrong):
Use Jython, an example: http://blog.databigbang.com/web-scraping-ajax-and-javascript-sites/
Use Java together with htmlunit
Use a proxy, an example: http://grep.codeconsult.ch/2007/02/24/crowbar-scrape-javascript-generated-pages-via-gecko-and-rest/
Use python together with qt or PyV8
Because I want to make a tiny tool to meet my request, and I thought it somewhat complicated to install V8 and qt, although python is my first choice.
So I tried to make a proxy with gecko, but it seems need a DISPLAY which I can not afford in a remote Linux server.
Now I am trying to use jython, but it seems there is no simple way to just convert a whole page to plain html.
Actually, I want to ask is there a way to convert a web page contains javascript to plain html, just like the brower does. Can node.js do this job?
I've recently built a server on top of PhantomJS that does this. I highly recommend this route.
http://phantomjs.org/
Basically, you write a quick script that has PhantomJS run the page, and configure a trigger method that lets you know the page is finished and sends the data off. My version used the built-in HTTP server, so PhantomJS easily served up the results on its own. This takes about 15 lines of code to do. (Sorry, can't paste it here... wrote it on work time. But, check out the example on their home page. It's almost complete!)
What is the best way to save a file from internet on javascript and/or C and/or even C++?
I saw this same question for C# and Java, but nothing to this three languages, so here is the question.
Hey, not so easy. The url point to some http://xx.xxxx.com/p.php?pid=staticetctectc....
I guess is php code which produce a nice gif in my browser. I just want to save this gif. Without opening browser. It is possible to do with javascript/C/C++?
Most near answer I found is this.
Thanks in any advice.
You can easily do this with JavaScript using Node.js. Here is a link to an example: http://www.hacksparrow.com/using-node-js-to-download-files.html
You could also do it from the command line using wget or curl. They are both available on pretty much every platform you can imagine.
For C++, you could do it like in Downloading File in Qt From URL. If you do not want to depend on Qt, libcurl is also an option.
For JavaScript, the method described in File Download Using JavaScript should work.
I am extracting content from a web page using JS/JQuery and want to write the data to a comma separated file. I know javascript doesn't really support file io and I'm trying to avoid setting up a local apache server just to process the content to a file. Is there an easier way to do this?
You can have your JS create the file text in a string. Then open a new window and write the string into the new window.
You can write a Mozilla Extension.
PROs:
You can use JS/JQuery on the extension
You can write files on the extension
CONs:
You can only use the application in Firefox (or any other Mozilla based browser).
There is no simple way of doing this. W3C has recently published the first draft of a File API that will make it possible, but it'll be a while until this is through and widely implemented.
Still requires a webserver, but you could build a small one method web service that your js calls, then the service can write out the data.
I need to edit an xml file using javascript. Now I'm involved in a project of online testing.
The question.xml file is already in the project folder.
In that i want to add or edit the questions(only using javascript). I'm able to bring the particular content through ajax, but I am not able to edit the file.
Javascript can't write to a file. The best you'll be able to do is get Javascript to read and edit the XML then post that data to a server-side script to write to file.
Until now, Google Chrome is the only web browser that has a functioning implementation of the FileSystem API, therefore, it may allow you to save files locally using only Javascript.
Obviously, for security reasons, when writing files to the local file system, the user must explicitly allow it.
A working tutorial: http://www.html5rocks.com/en/tutorials/file/filesystem/
Nickf is correct. The reason Javascript can't write to a file is because it is a Client-Side language. Javascript will never have permission to write a file because it has to operate inside the browser sandbox.
You will need to use a server-side script (.NET, PHP, ColdFusion, etc) to write the file.
If you are willing to use Google Gears, you get a sandbox on the client machine on which you can write files.
Javascript has no built-in file I/O (a.k.a. you can't do it with JS alone)
Instead use some kind of server side language such as PHP or ASP.NET in conjunction with Javascript's AJAX functionality.
Look over Adobe's Flex development system. There are ways you can use it to build an app that runs in the browser (or not) and can access the filesystem (Windows/Mac/Linux). It's programmed in ActionScript, a dialect of javascript; and can interoperate with javascript in the browser.