Is it possible to use PDF.js without having the website online? I'm trying to do a simple offline website that reads pdf using pdf.js but it won't work without being online.
Anyone could help?
Yes absolutely you can use it offline. Download the latest version here.
Now extract the zip file and put it on a server(use xampp/wamp/lamp or any other localhost) because the worker is not enabled for file:// urls.
To show the pdf files traverse to web/viewer.html from the localhost and it should load its default pdf.
As to the question about how to show your pdf's use: viewer.html?file=relative/path/to/your/pdf
Say for example inside the web folder(the one in which viewer.html is there) of your pdf.js you create a directory say named pdfFiles and in it you add a pdf named say mypdf.pdf in it then to display it use: viewer.html?file=pdfFiles/mypdf.pdf and it will display it.
Look here for more details on how to dynamically assign PDF file paths to the viewer. If you have any other queries let me know. I have used pdf.js offline and it works wonderfully on almost all the browsers I know.
Related
I am new to web dev and currently building a very basic page using Html/CSS and JS where users can upload the image and I can download it in my local system. But by default images are getting downloaded in the 'download' section of my desktop and I want to save them to any specific folder. How can I add this functionality?
You can't.
You do not have access to other peoples file managers as that would be a major security risk.
Uhh... You can't manipulate the download folder from frontend. It may be a security risk.
This cannot be done by Javascript (otherwise we could all produce websites which saved files all over a user's local PC).
As the end user in this case you can go into your browser and tell it which folder to save downloads in by default. (And remember to change it back if you want any other downloads to go elsewhere).
Here for example is what I find on Edge on Windows10 when going into Settings>Downloads:
I want to open a file in its Windows default application.
Actually, the scenario is as below:
A file is saved in Database and it is shown as a preview in CKEditor
When I double click on that file, it should open in its default application. The file can be a Word or Excel or PDF file
Then the user will edit the file in that default application
And when the user saves that file or closes the document, it should be updated on the server also it should refresh the file preview in CKEditor
I just want to know if there is any way to open the file in its default application.
Things I have tried:
I tried to use the ActiveX object to open the file, but it is not supported in Chrome and Firefox. And anyway, many forums are saying that it is the end of ActiveX era.
Tried to find if there is any CKEditor plugin, but did not find any.
Thank you in advance for your answer.
Short answer: no. Can you imagine the security nightmare if JavaScript was allowed to execute arbitrary binary files on a user's machine?
Your solution is going to be to find a JavaScript library that allows for handling those files, similar to how PDF.js was made for PDFs in-browser.
I'm wondering if it's possible to for certain JS files to be added to the web extension directory later?
Like say I have an app where users can select certain settings from within the app and those files (js and html files, images or blobs) are somehow added into the extension from the web. Like some sort of ondemand updater without using any native apps but it seems that upgrades are done by the appstores automatically.
I'm reading the files using ajax and adding them to indexeddb but because it could be more than one file that's getting messy.
Say a user wants a certain feature on the extension and there's an html page, js files and images then this gets downloaded to a certain folder inside the installed extension.
function download() { //only saves to downloads directory
var imgurl = "https://www.google.com.hk/images/srpr/logo11w.png";
console.log('download');
browser.downloads.download({url:imgurl},function(downloadId){
console.log("download begin, the downId is:" + downloadId);
});
}
I also tried the chrome download function above but that only works for the downloads folder not the extension folder.
Is there any way to make a custom updater?! I know we can't save to disk but any leniency or workarounds for the extension folder?! Even something silly like making a shell call to some dos (and linux/mac) thing that saves the file to the extension folder. I can fetch the files, just not save them.
Ok so I'll put it as an answer. This is the solution I'm leaning on which works for my scenario and I've listed some alternatives below:
Having the other files as separate extensions and giving the user an install link instead where they can install that extension, then those child extensions talk to the mother extension and they know the address to the resources in their child extension folder, so the mother gets the just the file locations from the children to load those assets from that folder. The child extensions are like bundles of those html and js with a background script which sends the addresses of these items to the mother.
https://developer.chrome.com/extensions/messaging#external
The drawback is that I'll have to see how that affects the urls like if I inject the html page from the child extension folder into the main interface using ajax then I can't use relative url's to any images in that 'cos the urls are relative to the mother extension folder.. I'll have to rewrite the child extension urls with the absolute paths into the html page to load images and js from the child extension html code which has relative urls.
Pros:
Cleaner and more persistent than indexeddb.
Files can be loaded normally from disk.
Cons:
User has to install separate extensions.
URL structure might be a bit confusing, need to rewrite urls if loading html from child. However this is only for image src's and where the javascript is loaded from so it's not such a big deal.
Other Possible Solutions:
Indexeddb which I'm already doing seems to be the preferred way of doing this but I really do not want to store every html asset in indexeddb. The upside is that while extensions need to be installed, this method can be done silently fetching and adding files without user interaction and indexeddb seems to be somewhat persistent. Might still end up using this because it is silent but having to load each asset from a database sounds like a nightmare.
The File Handle Api might have worked if I was working on Firefox only https://wiki.mozilla.org/WebAPI/FileHandleAPI
I haven't tried the shell copy, maybe if I fetch with ajax and then save to disk using some dos function and then doing different save functions for different OS systems.
Filesystem Api only saves to downloads and doesn't work for extensions anyways, so that's useless.
UPDATE
In windows there isn't any sudo, but this worked without admin priveleges for a subfolder (not on the C:\ root though). It would work for a linux only app very nicely. If I just wanted to save a file to a windows machine this might work.
Shell copy method would be to grab the contents of file with ajax from the local or remote location, output to DOS as a stream to save to file on windows. And do this for every operating system with a shell exec command or detect the OS and do that command. This way I can even put the files in the exact folder location.
Like say I make this sort of command from the contents:
//To append you can use >> instead of >
//folder seems necessary, can't save to root without admin
echo the content I want to save > C:\folder\textfile.txt
I thought of calling it using shell exec that only works in nodejs, so digging through the other answers on
How to execute shell command in Javascript
//full code to save file using javascript on windows
var shell = WScript.CreateObject("WScript.Shell");
shell.Run("echo content to save > C:\folder\textfile.txt");
The shell command doesn't seem to work. i can't find what this is for. There doesn't seem to be a shell command in regular javascript for windows. It seems to require IE ActiveX. Doesn't work with Firefox or Chrome.
Extensions can't modify their sources because the browser verifies them and resets/disables the extension if they change. Also, in Firefox the extensions aren't even unpacked.
The solution is actually quite trivial: save the code in any storage (localStorage, chrome.storage.local, IndexedDB) as a string and then add it in your extension page as a standard DOM script element. You'll have to relax the standard CSP a bit for that.
My problem is the following:
I use PDF.js to display a .pdf on a website. However the .pdf must be included from some url. That means, that if one downloads the website for offline purposes, the .pdf will not be included and therefore can not be displayed. Thus I wonder, whether it is possible to embed the .pdf (e.g. in an html-container), so that it can be found by PDF.js. In this case, offline mode would be easy to achieve.
I think this can't be achieved without using a localhost (or a browser plugin etc.).
As the title indicates i want to have a certain application get access to the local file system. To describe why i will illustrate my situation:
I am a running a IIS WebApplication with the C# MVC 4 Framework as backend module. The site solely consists of HTML, CSS markup and some JS. The page will be loaded in IE11+ (Edge) only. For the standard procedure of displaying and accessing data from as well as sending data to the server this works quite fine.
On a certain page I want the user to be able to upload a file using a simple file dialog, like the one you can initiate with a simple <input type="file"> tag. I also want to offer the posibility to download files from the server but need to know where files has been saved / will be saved to.
As described on a lot of different websites, just like this one here, the HTML5 File API does a great job but will not be able to return the full qualified filename including the local path directions, same for JS accessing the file object.
As my research confirmed HTML5, JS and also SWF (Flash) will not report detailed information because they are all sandboxed applications or restricted by RFCs. I already unterstood and appreciate the effort to secure my trips to internet.
But in this case do need the paths where a file was upload from and the file has been downloaded to.
So my question is, what is the best way to expose the full path directions for a up- as well as downloaded file to report them back to the server?
Is it possible to embed a SWF object inside HTML which will run inside an Adobe AIR sandbox or is a signed JAVA Applet still the one and only solution to accomblish this security breaking task?
A solution i would also apreciate would be the possiblity to ask the user to get access the file system, like you grant access to the web push service to receive notifications.
Also if there is a possible solution which may suite my circumstances please let me know by adding some simeple examples / revealing some factful links, thanks in advance.