Is there any way to read the contents of a text file from a client browser? For example, I would like to let the user click on a button to place the contents of C:\cmd.txt into an html element for view.
This will not be possible without user consent (I hope!!!). A website can not read a file on the client machine without asking the user. Think of all the security risks it would imply if it could...
Your solution could be to ask the user which file to open and then have them select the c:\cmd.txt file. After that, reading the file is easy.
Hope this helps
#Rick van den Bosh is correct as to your basic options using native HTML and javascript.
The only additional options would be a Java applet or browser plugin. However, your users would have to trust you enough to install your control, and savvy users aren't going to do that unless you are a major site like amazon.com or cvs.com or some well-known commercial enterprise.
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We are currently looking at porting a enterprise silverlight application over to html5. The major roadblock that we have hit is the ability to open files from the user's local disk. Currently they have a document library which just links to files on their computer that they can open from within the app and view or print out. All that I read is that you can only access the local sandbox of the web app with the html5 file api's. We want to load these files from code.
Does anyone know of any workarounds to this?
Thanks
There is no way for html5 to access local file without user selection. But FSO: FileSystemObject works for IE and MAYBE could be regarded as a work around. But still there are some requirements to meet.
It is possible to use chrome's filesystem API to access files on a users local filesytem. So you'd have to be willing to make this a chrome only application.
Using java you can create a "Signed" applet which has access to the local filesystem. (if the applet is signed you can request filesystm permissions)
then there is a tutorial for accessing methods of your java code directly from javascript here: http://docs.oracle.com/javase/tutorial/deployment/applet/invokingAppletMethodsFromJavaScript.html
you should be able to perform something similar from silverlight.
There is no workaround in pure HTML5/Javascript. You need the use of plugins, such as Java or Silverlight (maybe you shouldn't port it after all). As for workarounds, HTML5 gives you an easy way drag and drop multiple files that you could transfer on the server and then display back to your users. Another workaround would be to install a custom agent (a software with only a tray icon) that would send the information about the current user "document library" to server and then again, you could display it back to the user.
Note: I've heard somewhere that browsers will eventually stop supporting plugins. http://www.howtogeek.com/179213/why-browser-plug-ins-are-going-away-and-whats-replacing-them/
Ya, I agree with Markain. However, if you were to limit your audience solely to chrome users, I daresay, you would most likely use some of your users. If Huazhihao is right, then your number of leaving customers should decrease but users who regularly use firefox won't be happy. Overall, I think that this will not work. Otherwise, there would be too many websites that trashed your hard driver (or at least wherever you have the rights to edit/delete files). I think it would be best if your product was setup to synchronize the file whenever an internet connection was detected and a change was made to the file. That way the user would not need to visit the website whenever the file was uploaded. If this is some kind of an error file, then it would be most beneficial if you were to make a link in the application that when clicked, would upload the file to the website and the website were to do whatever was necessary. If this is a purely online thing, then I don't see what business you would have looking through other peoples' files =-). Hope I helped!
Quite a few of the sites that the schools I work in use have user accounts to protect the content from people who haven't paid for it which means that the users (aged 5+) have to type in some pretty weird usernames/passwords before they can do their work.
I was wondering if it possible to use Javascript to create a page that would let me do something along the lines of:
Fetch the Login Page
Fill out the form
Submit It
Redirect the user to the site
1-3 would happen in the background without the user seeing it.
In most cases these accounts are shared and the details are on displays etc... in the classrooms so there is no issue with the details being publicly accessible.
I have used Mechanize in ruby before and would imagine a solution like it but running client side.
I know that some inspection of the target site will be needed but once I have an in-principle example I should be able to tailor it to each site later.
If you have a standardized browser, you should consider building a plugin for that browser, that's the easiest way to interact with the web pages. Otherwise you'll get into issues with anti-CSRF protections and cross-domain-policies.
As for the language, Chrome extensions are written in javascript and are pretty easy to build. For the other browsers I don't know.
Please hear me out before you start crying security issues.
This is for an intranet application, hence I have full range to install any plugins or change any security permissions to suit.
What I want is for them to go to a webpage and click a link to download a file, such as a Word Document. This gets transferred to local storage of some kind (sandboxed if need be) and then is opened in word as a regular file.
When they click save, JavaScript or something will pickup the file is saved or the program is no longer accessing it and can be actioned upon, such as uploading back up to the server.
Is there any way to do this. I have looked at IndexedDb, WebStorage, HTML5 FileSystem API but I am new to all and don't see a way to do this.
I am open to coding any needed plugins as long as you don't mention Flash. The main issue I am coming across is opening a file downloaded into some form of local browser and then opening it via a desktop application, e.g. Word.
Any help, greatly appreciated.
After much research the only way to do it is with a plugin. IndexedDB, FileSystem API or WebStorage can not access the local file system. Which is good.
Silverlight is a good option for intranet and .NET, which is what I have chosen to go with.
Silverlight 5 in full permissions with a file watcher. The file watcher can be accomplished with this method: Is there an alternative to accomplishing what the FileSystemWatcher does in Silverlight?
I'm trying to list all of my bookmarks using Javascript. Is there any way that I can accomplish this? Thanks in advance for any help.
In web design, there are some limitations due to security. Such as this, javascript would have to read your web folder on your computer and display the information from your computer. That would be bad security wise.
Use social bookmarking, and update it when you need to.
The only way to show your bookmarks is though xul aka an extension if this is what you want then look up places api. Places is a sqlite database located n ur profile folder.It's name is places.sqlite
If you use Firefox, there is a file called bookmarks.html in the profile folder. You can open this file and insert some JavaScript.
But as mentioned before, you can't (for good reasons) not access the bookmarks directly using JavaScript from any page.
I am trying to do a simple thing:
Let the user choose a txt file, and save its context to be used on the client side only.
no server side needed.
Is it possible ?
Thanks.
It is possible to do so with HTML5 Files API as explained in these resources:
https://developer.mozilla.org/en-US/docs/Using_files_from_web_applications
http://www.html5rocks.com/en/tutorials/file/dndfiles/
I guess you mean "save its content" and conclude you want to do anything with this content on the client side, e.g. extract some parts to fill a form. Anyway saving the whole file unchanged, on the same machine where it comes from, does not make sense.
So the problem is not how to upload, but how to open/read a file. You can do this with a Java Applet, Flash, Silverlight, ActiveX ... just to name a few.
JavaScript is not an option. It cannot access the file system.
If the html page, that is hosting your javascript, is from a remote server. This script is not trusted to do actions on your local filesystem.
<Obscure solution mode level = 1>
You can give more trust to a page, but this is something your user has to do. If this is an app/web only for use within an enterprise, you can probably do this centrally. And every browser handles this differently. So it is not something you can rely on, when you do not have a limited userbase.
<Obscure solution mode level = high>
If your (enterprise) users are using Internet Explorer, you could also create a HTML Application (simply give your html page an hta extension). These pages have full trust, but can only be started from a trusted location, or require confirmation from the user.
The only way you can acheive this successfully is to build an ActiveX type plugin/component (or java applet) you will have much more control of the client machine.
No. JavaScript cannot access the local filesystem.
However, you could install a webserver on your machine and e.g. run PHP on that one. Then you could do it without ever sending your data over a network connection. That would require you to do your data processing in PHP though.. probably not what you want. Or you could simply send back the data to your javascript.. but that'd be pretty awful to run an upload just to make the data available to JavaScript.