How do I access a property file using javascript. Normally property file is a xml based file.
I java we access a property file like this:
Properties prop = new Properties();
fis = getClass().getResourceAsStream("props.xml");
if (fis != null) {
prop.loadFromXML(fis);
}
String dbUrl = prop.getProperty("dburl");
I want to do the same but using javascript. is there a possible way of doing it?.
JavaScript can't load files, as part of its security model. It can retrieve XML from the server using AJAX, but it can't read files from the client computer.
You can't load any files from the users computer with javascript in the browser.
If the file is from your own server you can load it, like any other ajax, with XMLHttpRequest.
Javascript doesn't use property files, as, either it has all the information it needs in the javascript files or in the html, or it will make an XMLHTTPRequest call to get the information from the server.
The server can look at the property file, and may use information passed in from the request, such as the header information, to know more about the client, to determine what information to pass back.
So, if you want to pass back some localized information, the server would have to get that from the browser request and then it could send back just what is needed for that transaction.
Javascript is different from java, so one limit is that javascript cannot read from the hard drive of the user, and since it is a webpage, the user wouldn't have the property file installed, it would still be on the server.
Javascript can only make requests to the address that that script came from, so there is a second sandbox rule that has to be met.
You may want to better understand javascript, then try to rephrase your question.
HTML5 now allows JavaScript to read local files, via the File API:
http://www.html5rocks.com/en/tutorials/file/dndfiles/
Related
So I have a web page, and I would like to programaticly create a text file (lets say it has the words 'hello, I am a text file' in it) on a new directory on my website. The program will be in another directory on the website.
e.g.
https://www.example.com/txtbuild.html is trying to programaticly make https://www.example.com/texts/hi.txt
Is there a way to do this with HTML/Javascript?
EDIT:
I am on Github
You can't do it with HTML/Javascript alone, you need a functional language on the backend (nodejs, php, python)
You can use ActiveXObject, but it won't work in all browsers.
var fso = new ActiveXObject("Scripting.FileSystemObject");
var a = fso.CreateTextFile("c:\\testfile.txt", true);
a.WriteLine("This is a test.");
a.Close();
https://msdn.microsoft.com/en-us/library/5t9b5c0c(v=vs.84).aspx
If, when you say "JavaScript", you're referring to a node.js application running on a server, then this is possible. It doesn't have to be node though; it could be a Django site, or an ASP.Net site, doesn't matter. You can't have JS code in the browser create files on your server... the JS in the browser is executing on a client machine, and doesn't have access to the server's file system.
You could create an endpoint to which your clients could send requests that would initiate the creation of the file.
You could also allow clients to PUT or POST files to your server, but again, this is something you control from the server side of the application. Your webpage (i.e., HTML file as you put it) cannot create files on the server itself. Your server allows clients to send it files in a specific manner, and the client must adhere to those rules.
The short answer to your question is no.
The long answer is that you have the following alternatives:
Use a form on the Browser end, send the data back to the server, and then use a server-side language such as PHP to receive and save the data. No JavaScript required, but you do need server-side programming.
You can make the process more immediate by using JavaScript on the browser end to send data back to the server. This is called Ajax. You will still need server side processing, though.
Note that it is probably a very bad idea to simple accept user data and save it directly. There are two things you should consider in your development:
Always filter the incoming data against the possibility of receiving and accepting carefully crafted malicious data.
Consider storing the data in a database. Apart from being easier to manage (you don’t have to worry about filenames, for example), they can do less damage there.
You can achieve this in IE browser using the following code.
<SCRIPT LANGUAGE="JavaScript">
function WriteToFile(passForm) {
set fso = CreateObject("Scripting.FileSystemObject");
set s = fso.CreateTextFile("C:\test.txt", True);
s.writeline("HI");
s.writeline("Bye");
s.writeline("-----------------------------");
s.Close();
}
if you are looking for a goos reliable solution then better to use PHP and other server scripts.
I have a fairly large Application and I'm currently trying to find a way around having to pass Data from PHP (User Tokens for 3rd Party API's and such) through the DOM. Currently I use data-* attributes on a single element and parse the Data from that, but it's pretty messy.
I've considered just making the contents of the element encoded JSON with all the config in, which would greatly improve the structure and effectiveness, but at the same time storing sensitive information in the DOM isn't ideal or secure whatsoever.
Getting the data via AJAX is also not so feasible, as the Application requires this information all the time, on any page - so running an AJAX request on every page load before allowing user input or control will be a pain for users and add load to my server.
Something I've considered is having an initial request for information, storing it in the Cache/localStorage along with a checksum of the data, and include the checksum for the up-to-date data in the DOM. So on every page load it'll compare the checksums and if they are different (JavaScript has out-of-date data stored in Cache/localStorage), it'll send another request.
I'd rather not have to go down this route, and I'd like to know if there are any better methods that you can think of. I can't find any alternative methods in other questions/Google, so any help is appreciated.
You could also create a php file and put the header as type javascript. Request this file as a normal javascript file. <script src="config.js.php"></script> (considering the filename is config.js.php) You can structure your javascript code and simply assign values dynamically.
For security, especially if login is required, this file can only be returned once the user is logged in or something. Otherwise you simply return a blank file.
You could also just emit the json you need in your template and assign it to a javascript global.
This would be especially easy if you were using a templating system that supports inheritance like twig. You could then do something like this in the base template for your application:
<script>
MyApp = {};
MyApp.cfg = {{cfg | tojson | safe}};
</script>
where cfg is a php dictionary in the templating context. Those filters aren't twig specific, but there to give you an idea.
It wouldn't be safe if you were storing sensitive information, but it would be easier than storing the info in local storage,
My web application uses file which has been updated by other process. My application reads the content of the file using ajax
xmlhttp.open("GET","/config/myfile",false);
xmlhttp.send();
Once response is received then app parses this response and shows that values on Web UI. The file contains 50 fields and whenever I want to read any single field I need to open whole file.
Is there any way to get the values of single field based on key instead of reading whole file.
As per my understanding we need to read and open file and then parse the response text. But would like to know is there any way to reduce the file calls with any other method.
I want to achieve this to reduce the file I/O operations. Since other processes are writing in to it and at same time my web app accessing to read the latest value.
Any other option would be appreciated.
Note :- I do not have to use any server side scripting lang option.
Regds
I'm working with a .js client and have and object that I need to write out to a file on the server. A couple of questions - file i/o with JavaScript is new to me... I was planning on using jquery and json. I'm using java serverside. I don't have a problem reading what I get back from my servlet, but the file i/o is killing me! A couple of questions:
I can open a file I generated myself via the .js with an $.ajax call, but it's not handling my json syntax (I tried both an $.getJson and $.ajax - handwritten json, so I might (probably) are doing something wrong with it). I used firebug's console and it looks ok...
How can I write my object to a file on the server?
Then, when I want to read it, what do I need to do to process it? Right now I'm using a jsonFilter function (uses JSON.parse if that's available, otherwise eval) to process data that I'm getting from the servlet.
The object I'm writing isn't simple, but it's not super complex either. There's an array that contains an array, but that shouldn't make a difference if the software is both reading/writing it.
Thanks for any help! I'm at a loss - tried alot of different things.
You can open a file located on the server via ajax by querying the file and loading it into a JSON object. You might want to LINT your JSON
You can not write to an object on the server via the client. This is a severe security breach.
Common practice is to change the JSON data and then send it via ajax to server-side code. The server will then do the file IO.
Yes using JSON.parse otherwise eval is indeed correct. I would recommend json2.js
The data should be fine as long as it passes JSONLint.
Your main issue is that it's impossible to write to the server from the client. Get the client to load the data through ajax change it and then query the server to update the file.
js don't have i/o property;
you should use ajax or http request to send message to server,and tell server to do de i/o action...
Is it possible to get temporary filename with javascript?
I want upload a file using ajax... So, i want to get the tmp filename with js. Is this possible?
AJAX itself won't let you upload a file via a web form - you need to perform a traditional form post to a window (or a frame/iframe) in order to send binary content. Such a post must be handled by your server code (in Java, PHP, python, etc), which can process the stream into a temporary file (some languages/frameworks such as PHP can do this automatically).
You can then make the temporary file available via a URL scheme, and return this URL back as the result page of the post. If this is all on the same domain as your main page, you can then use Javascript to look "inside" the result iframe to find the temporary URL.
If your using AJAX in combination with your server side language just return the temporary name and pull it in with the AJAX, if can all be done in 1 call.