As I have read, it is not easy for JavaScript to modify files on client PC. I am working on a web based file manager and would need to know the following:
Can JavaScript list files and folder structure on a client PC?
Can JavaScript list files and folder structure on a server?
If your answer is no, that Java Scipt can not list files and folders say on client's or server's C:\ drive, than would CGI script be the only solution?
Browser JS reading client PC's files: Depends
For a security reason, you can't access the files on the user's PC without the user's consent.
That's why the FileReader API is created around the file input box <input type="file"> and a drag-n-drop area since the whole idea is to "access the file with user's consent". Without the user intentionally putting the file for access, you can't access it at all.
Server-side JS reading own server's files: Yes
As for server, if you meant access the server using server-JS (NodeJS or Rhino), yes you can (How else would it serve webpages anyway?).
Browser JS reading own server's files: Depends
Accessing the server from the browser using JS works if you have an API to read files from it.
Browser JS reading other server's files: Yes, with a catch
To access other server's files without some API, you could resort to creating a web scraper or a web-spider that runs server-side (since browser can't cross domains due to the same origin policy) and have an API exposed to your browser.
However:
you can't crawl to all files as some may be restricted from outside access.
the public appearance of the structure could be different from the internal structure, especially if the site uses segmented url scheme
sites using query strings to generate pages cannot be crawled easily due to the number of permutations it could make, thus some pages might be unreacheable.
CGI won't be a solution either, as it only has access to the filesystem of your server, not that of the client visiting your site. The only way to access your client's filesystem from javascript seems to be the File API, which apparently is not implemented by many browsers.
It's a cludge but you could resort to a java applet or the dreaded active-x control.
Related
I'm trying to develop HTML base editor equipped with browsing local files function.
I know basically that is restricted by browser to open local files.
However I found out some method doing this activity.
using path begin from "localexplorer://" it works perfect for English path name.
But when I use Japanese folder name or file name it becomes error.
I tried to convert SJIS format that file names but this is not work.
Here is code.
[![error[![\]\[1\]][1]][1]][1]url = 'localexplorer:' + event.target.innerText;
array = str2array(url);
sjis_array = Encoding.convert(array, "SJIS", "UNICODE");
sjis= Encoding.codeToString(sjis_array);
window.open(url, '_blank');
According to browser security, javascript is only allowed to run in the sandbox, you cannot read or write arbitrary files:
JavaScript and the DOM provide the potential for malicious authors to
deliver scripts to run on a client computer via the Web. Browser
authors minimize this risk using two restrictions. First, scripts run
in a sandbox in which they can only perform Web-related actions, not
general-purpose programming tasks like creating files.
If the user selects a file via <input type="file">, you could try to read the content of the file through FileReader API, like this case: How to open a local disk file with JavaScript?
If you need to interact with files on the user's local device or a user-accessible network file system, you can try to use the File System Access API. And this must be done in a secure context, and must be called from within a user gesture. You can also read this article to learn more about it：The File System Access API: simplifying access to local files.
Thank you for your response, I solved this issue by Forefox plug in extensions, it seems like chrome did not support this functions even if there is plug in extensions.
I need to create an HTML page that will generate a list of hyperlinks to the contents of the client side directory in which it resides.
This would allow HTTP browsing of a local NAS, where no web server involved and contents can change dynamically.
This might be extremely useful to anyone serving content on a LAN. We need this feature in an educational setting, where directory contents will change frequently. Making manual links would be prohibitive, and file browser access is also needed.
Our Digital Media program will be much obliged to anyone who can help us with a solution.
Without any kind of server/back-end code, an in-browser NAS file explorer is not possible. Client-side JavaScript only interacts with the client. It's possible for client-side JavaScript to contact a server, however, and retrieve information about that server's directory structure, but, of course, that would require a server where you say you can't have one.
I am creating a HTML page where I need to display the names of the files present in the specific local folder, example - C:\Users\User1\Documents\folder1 . I tried to write the code in java script but have not succeeded yet. Most of the question threads mention about "ActiveXObject" to be used but that itself does not work for me.
Reference: JavaScript: Read files in folder
Can anyone help me in achieving this?
In general, you can't do that. Web pages do not have access to the local filesystem.
Chrome can access the contents of a directory that is selected using a file input field. However, other browsers, such as Internet Explorer and Firefox, have not implemented this feature at this time, nor is there currently any way to access a directory that was not selected by the user.
In theory, it is possible to read arbitrary files using a signed Java (not Javascript) applet. However, this requires the user to approve a series of extremely scary warning dialogs — and requires Java! — so it's really not a viable solution.
I'm afraid I may be the bearer of bad news for your design: The action you are requesting expressly violates the security model as specified in the File API spec. The client implementation of FileReader() must make sure that "all files that are being read by FileReader objects have first been selected by the user." (W3C File API , 13. Security Considerations: http://www.w3.org/TR/FileAPI/#security-discussion).
It would be a huge security risk of browser scripts could just arbitrarily open and read any file from a path without any user interaction. No browser manufacturer would allow unfettered access to the entire file system like that.
Thinking about it however, if it is all being run locally, you could use ajax to query a server side script that could return the directory you request.
I am creating a HTML page where I need to display the names of the files present in the specific local folder, example - C:\Users\User1\Documents\folder1 . I tried to write the code in java script but have not succeeded yet. Most of the question threads mention about "ActiveXObject" to be used but that itself does not work for me.
Reference: JavaScript: Read files in folder
Can anyone help me in achieving this?
In general, you can't do that. Web pages do not have access to the local filesystem.
Chrome can access the contents of a directory that is selected using a file input field. However, other browsers, such as Internet Explorer and Firefox, have not implemented this feature at this time, nor is there currently any way to access a directory that was not selected by the user.
In theory, it is possible to read arbitrary files using a signed Java (not Javascript) applet. However, this requires the user to approve a series of extremely scary warning dialogs — and requires Java! — so it's really not a viable solution.
I'm afraid I may be the bearer of bad news for your design: The action you are requesting expressly violates the security model as specified in the File API spec. The client implementation of FileReader() must make sure that "all files that are being read by FileReader objects have first been selected by the user." (W3C File API , 13. Security Considerations: http://www.w3.org/TR/FileAPI/#security-discussion).
It would be a huge security risk of browser scripts could just arbitrarily open and read any file from a path without any user interaction. No browser manufacturer would allow unfettered access to the entire file system like that.
Thinking about it however, if it is all being run locally, you could use ajax to query a server side script that could return the directory you request.
I am working on project for desktop application. I am using Qt controls with visual c++.
I am loading an html file in the QWebView as,
m_pWebView->load(QUrl("../../../demo/index_Splash_Screen.html"));
Now, what i want is, say, I have some .zip files in my location "c:\demo", I want list (or array of file names) of the files present in that directory.
How can i do this through javascript ?
PS: I went through this link, but it didnt match my requirement. I have not worked with of html, javascript and jquery. Please help me.
I'm afraid you cannot access local files or directories using javascript due to security issues.
Edit: I hadn't thought about the file api so thought for a moment this might not be true, but without some user input to give permission, this still cannot be done.
This question has a good response from PhilNicholas:
I'm afraid I may be the bearer of bad news for your design: The action
you are requesting expressly violates the security model as specified
in the File API spec. The client implementation of FileReader() must
make sure that "all files that are being read by FileReader objects
have first been selected by the user." (W3C File API , 13. Security
Considerations: http://www.w3.org/TR/FileAPI/#security-discussion).
It would be a huge security risk of browser scripts could just
arbitrarily open and read any file from a path without any user
interaction. No browser manufacturer would allow unfettered access to
the entire file system like that.
Thinking about it however, if it is all being run locally, you could use ajax to query a server side script that could return the directory you request.
If it is a Windows application then you could access the local filesystem by using ActiveX objects. You might have a look at this link Reading a txt file from Javascript
Note that activeX usage is possible only when using IE as browser/engine; I used to need it a while ago for developing an HTML application (.hta files).