I am trying to make a JS program using a text file on the client side. The thing is that it was difficult to find out how to do such a basic functionality because it is not a desired feature. I want to open a text file which is not in the local directory of a user but in the directory with the html file. So, what I want is the JS version of this code (which is in python)
# Open a file
fo = open("foo.txt", "wb")
fo.write( "Python is a great language.\nYeah its great!!\n");
# Close opend file
fo.close()
Thanks!
You can read a file with FileReader() (as a result of a user selecting files) but fortunately we can't modify client's or server's files with JavaScript in client side (there is no FileWriter()). To do that, you should upload the file to the server (through Ajax or a simple html form) and modify it with server side code.
Related
Is it possible to create a python script (eg. main.py) which creates the GUI window, which loads a .html file (with necessary css and possibly javascript), and have this .html file GUI interact with the main.py?
For example, in the .html file the user might click a button, which needs to interact with a function in the main.py file, and return a result in the .html file (python probably cannot edit the html dom, but may return a result the javascript can?).
I read PyQt5 can create a webview (load html files locally or externally), but I need it to interact with python for returning results.
Thanks!
If a browser plugin is sending messages to a .bat file, what is the correct way to send that message? I have seen the following examples:
var sending = browser.runtime.sendNativeMessage("ping_pong", "ping");
And
var port = browser.runtime.connectNative("ping_pong");
port.postMessage("ping");
In that example ping_pong is the name of the native application in the Windows registry.
Edit:
I am trying to use Native Messaging as described here:
https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Native_messaging
I have created a Firefox plugin which sends a string to a batch file using the code shown above. I have also created the registy entry and JSON file for the application as described in that link. The JSON file contains a link to the batch file so that the plugin knows what application to call.
The batch file can accept a parameter using %1. However the value of %1 is the name of the JSON file and not the message that was sent to it using JavaScript.
Edit 2:
It the example given in the link above it is a Python file that handles the standard input. Thus a batch file calls a Python file to handle the messaging. I used a Java file instead. This resolved the problem and it works without problems.
I am trying to run a script that will run every 5 minutes in a shared hostings wordpress folder that will rename the newest CSV file in that folder.
/wp-content/csv/sample.csv
I tried putting a js file in the folder within that folder and run it.
var fs = require('fs');
function runClear()
{
fs.readdir("", (err, files) => {
files.forEach(file => {
console.log(file);
});
})
}
runClear();
setInterval(runClear, 300*1000);
However, it seems like I got client side and server side scripting confused. It seems like I need node.js.
What would be the best approach for this?
Regards,
Yes you are right you are confused in client side and server side script.
Javascript is a client side script which deal with all the user interactions like what will happen user click something or submit a form, hover over some element, scroll the web page etc.
Where as server side script like php deals with data stored on server like mysql records or the physical files.
what you are trying to do is to change the server resource from client side script. and you can not do that directly.
Instead you can call an ajax function which send an HTTP request to some script placed on server. And in that server script write the code to read the existing files in a directory and rename them using file handling operations.
I'm trying to modify the project so I could plug in a file path or a file as a variable instead of the user choosing the model file. So I'm looking for where the actual upload happens.
In submitProject():
https://github.com/cyrillef/extract.autodesk.io/blob/master/www/js/app.js#L129
I see that it just sends (with an ajax request) an object that holds the file name and unique identifier but not the actual binary file.
In here:
https://github.com/cyrillef/extract.autodesk.io/blob/master/www/js/upload-flow.js#L34
there's r.upload(), is this the actual upload of the model?
Does it start to upload the file right as you press ok in the file chooser?
Is there a way to give it a file path to upload instead of uploading with the form and file chooser?
The author of this sample should be on Christmas vacation, I just downloaded and setup the extractor sample on my machine, with a little debug into the code, let me try to answer as much as I can.
In general, I think some of your understanding is correct, but let me explain a little more:
For a local file to be uploaded and translated, there are actually 2 steps of actual “upload”.
As you mentioned, when you press ok in the file chooser, yes, the file will be first uploaded to the "extractor" server as you noticed by some methods like r.upload(), it’s actually using a JavaScript library call “flow.js", which provides multiple simultaneous, stable, fault-tolerant and resumable/restartable file uploads via the HTML5 File API. I am not expert on this, but you can check that module about how to use it to upload a file.
By now, your file is uploaded from client to the "extractor" server, but if you want to translate the file to "svf", the file is required to be uploaded to Autodesk Server(OSS), that is done by clicking “submit my project” buton, when you click this button, as you mentioned, from client, it will call the method submitProject() in https://github.com/cyrillef/extract.autodesk.io/blob/master/www/js/app.js, this method will send a post request of “/api/projects” to the "extractor" server, if you check the code at server side https://github.com/cyrillef/extract.autodesk.io/blob/master/server/projects.js , you can see the extractor server actually upload the file to Autodesk OSS, and then triggers the translation service.
This feature (passing a URL string vs a file binary) is already implemented. You can use the uri: edit box and paste your file URL there. It supports http(s) or S3 uri with access token.
The physical upload happens in this file, whereas the SubmitProject() code sends only information as JSON. The JSON object only contains a reference to the file which was uploaded using flow.js. But would contain the uri string if you had choose that method.
I need to run a .bat file when the user clicks a link on the webpage. The .bat file basically runs another executable file and saves its output in a text file. So what I want is to create that text file once the user clicks the link to the .bat file on the webpage. Now, my .bat file is working perfectly when I execute it separately it creates the text file with contents, but somehow when I click the link it creates an empty text file. I looked at all the paths, they are all good;
I am using
Batch File ,
I have also tried
function runApp(which)
{ WshShell = new ActiveXObject("WScript.Shell");
WshShell.Run (which,1,true);
}
But both of them just create the text file, and not put the contents
Does any one has any idea about this, also is there any other way to do this, like running the original .bat file and then getting its output in a text file directly with html/javascript?
Appriciate any help
Thanks
You don't say anything about what environment you are working with and I would guess you're not working with a server-side environment. JavaScript normally works in a browser to respond to the user's clicks and mouse moves etc but strictly within the confines of the browser. What you are trying to do is perform I/O operations on the underlying OS that the browser is running in (if you are running locally) or on the server-side OS in a normal webpage environment. It's not just a security issue - JavaScript simply doesn't have any direct connection to the client's OS or the server-side OS for that matter.
What you need is a web server environment like Apache or IIS etc, probably running an environment like ASP.NET, JSP, PHP(with a nice framework like CodeIgniter), or, rather you than me, CGI.
The user clicks a link or a submit button, and sends a request to the server. The relevant server-side program processes the request, runs the I/O operation you talk about and responds with the text. JavaScript is irrelevant in most of that process. It only comes into its own again when you are trying to figure out how to display the response in some fancy dynamic way.
There are millions of tutorials out there:
Tomcat (Java) http://wiki.apache.org/tomcat/GettingStarted
.NET(C# or VB) http://www.asp.net/get-started
Codeigniter (PHP) http://codeigniter.com/
CGI (not for the faint-hearted) http://www.cgi101.com/book/ch1/text.html
Having said all that, there is a server-side JavaScript environment (http://nodejs.org/) but the point is you will always be restricted by the limitations of the http protocol which means that you send a request to a server, the server processes your request depending on your privileges as a client, performing an I/O operation if appropriate, and responds with a stream of HTML. It does not allow direct operations on the server.
None of this is easy. Expect steep learning curves.
Displaying the text file contents
Here's a sample JSP page which will read the contents of a text file then display it on the webpage. I haven't added any buttons or anything - it just demonstrates how to read a file on the server:
<%#page contentType="text/html" pageEncoding="UTF-8" import="java.io.*"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>BufferedReader</title>
</head>
<body>
<%
String path = this.getServletContext().getRealPath("/target/message.txt");
File file = new File(path);
FileReader reader = new FileReader(file);
BufferedReader br = new BufferedReader(reader);
while(br.ready()){
out.print(br.readLine() + "<BR>");
}
reader.close();
%>
</body>
</html>
/target/message.txt is the virtual absolute path (from the root of the webapp). The call to getRealPath is the way you get a real physical path that allows you to create a File object.
I'll have a look later at using exec to run a batch file, but now you're thinking of a powerful language/library like Java why do you want to run a batch file? Wouldn't it make sense to write the program in Java?
use child_process.spawn of node.js