In my web app I need to give the user the option to save a js variable as a file (when the user clicks download, the app offers him to save a file, preffereably as .js file).
Similarly as google docs offers you to save a file.
Is it possible for javascript to pass it's variable this way?
Check out Downloadify which allows exactly this.
Downloadify is a tiny JavaScript + Flash library that enables the generation and saving of files on the fly, in the browser, without server interaction.
it requires Flash installed in the user's browser to work, though.
I know of no other way of doing this without server interaction.
You might also want to check out OpenSave:
http://www.gieson.com/Library/projects/utilities/opensave/
... which looks much like Downloadify, but seems to have a few extra features (and not as complicated?).
Related
In a web application I am working on I would like to be able to download files, modify them localy and reupload them to the server.
To make it as easy as possible for the users, I would like them to choose the download location and use a single button to upload the changes afterwards.
My current apporach is the following:
Use window.showSaveFilePicker to choose location and get a FileSystemFileHandle
Download the content and write it to the FileSystemFileHandle
Show a button which allows to upload the changes using FileSystemFileHandle#getFile to get the modified content.
This approach works pretty well but the user has to manually search and open the file after the download and I would like to support them in this step and make it as simple as possible.
Ideally the file should automatically be opened with the default application after the download but I couldn't find a way to do that.
One idea was to open the file in a new tab using the file://-URL, allowing the browser to decide what to do but the FileSystemFileHandle does not seem to expose the absoulte path.
Is there any way to open the downloaded file with the default application? If not, what other possibilities are there to make the mentioned use case as simple as possible?
Thanks in advance
EDIT:
I found that you can open certain applications using special urls like ms-excel:ofe|u|file://path/to/file.xls.
This would be enough for most use cases but for this to work I would need to get the file url from a FileSystemFileHandle.
For security reasons, there is no way for a Web app to open local apps. In the future, though, once file change events are implemented, you can await changes to the file, and then re-open it. This should solve your use case.
I coded a local html file that kind of works like windows notepad would, using localStorage with JavaScript to auto save. To make new notes, I have just been saving the open file as another .html file and naming it something new for the note. But I have found this to be really annoying, because when I want to delete the note, I have to actually go into my Files app, find the .html file for the note, and delete it.
I know how to use event listeners and whatever, but is there a line of code I can use to delete the file or even just ask the user for confirmation to delete the file? I basically need a way for a local html file to be able to delete itself using JavaScript. Everything I have managed to find online says that you need Node.js and it has to be on a server, but I wanted to ask anyway, because I wonder if permissions are different when the file is stored locally and not on a server.
No.
You can't use browser JavaScript to manipulate the real local filesystem. (You could access a sandboxed one, but not the real filesystem.)
Hello! My question is about javascript.
I want to
1. ask a user to select a directory
2. then write my bunch of files to it (probably with creating sub-directories) without interaction with user
How can I do this? And can I?
I am new in javascript and I hope for your help.
PS.
I've heard about ability to ask a user to select a path by save file dialog and then save data to selected file, but i want to ask a user once for selecting a directory and then create a bunch of files in it without bothering a user for each one.
Javascript alone doesn't have any way to access the local computer's file system for WRITE purposes. Period.
However, Downloadify, by Doug Neiner, was built for this purpose and uses a combination of Javascript and the Flash library.
It needs Flash 10 to work.
Alternately, you can install apache onto the computer (or better yet, a full stack like XAMPP or WAMP/MAMP/LAMP) and use PHP (with javascript/ajax) to write files onto the local file system. However, this means that the website must also be hosted locally. Probably your best bet is Downloadify
Resources:
https://github.com/dcneiner/Downloadify
How to create xml file with jquery
Save content using Jquery? Write to file
Saving to server-side file using AJAX
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.
In my application I want to open some files with the correct default programmes, like .doc file should be open with WORD and .psd files should be opened with Photoshop if it is installed, and this should be done under html or java script.
Please tell me how to do it.
JavaScript cannot run programs, but if you have a file on your server you can simply link to it:
<a href='image.psd'>Download File</a>
Users will be promped to download the file or open it using the default program (for most files). Again - as others have said - this is determined by the browser. IE can open doc files on the browsers, and PDF documents can be opened that way too.
There is no way for you to choose which application will be used to open your files with javascript...It just doesn't have that power.
I don't think this is possible in JavaScript without using any activeX or something like that. Js has no access to locally installed applications.
Browsers typically don't have access to the computer's filesystem for security reasons. If you know the exact path to a file you can point the browser at it using a file: URI, e.g.
file:///C:/path/to/file.ext
You may also be able to do this with a plugin, eg ActiveX, however I am unsure as to what security measures that would have.
Invoke the system command 'open'. Works on Windows and Unix based clients.
Depending on where your script runs, you might not be able to invoke system commands though, for instance in a browser sandbox.
If you provide a link to a file on the local file system (eg: <a href="file:///C:/mydoc.doc">) then the browser will open it - however this is not a great way to do it since the browser will first show a dialog ("Do you wish to Save or Open") and then it will "download" it into temporary files as it would if the file were remote. In this case, if you edit and save the file, it'll be the version now in your temp folder. This might not be a problem if your files are read-only, but generally it's not a great user experience.
The only other method is to use ActiveX, which is actually rather easy (though I don't have the exact code on me now - write a comment if you're interested in a snippet and I'll update). Of course this comes with the giant flashing caveats of:
It only works in Internet Explorer.
You need the user to fiddle with their security settings for the ActiveX scripts to run.