[javascript] Cannot open local file - Chrome: Not allowed to load local resource

Test browser: Version of Chrome: 52.0.2743.116

It is a simple javascript that is to open an image file from local like 'C:\002.jpg'

function run(){

   var URL = "file:///C:\002.jpg";

   window.open(URL, null);

}
run();

Here is my sample code. https://fiddle.jshell.net/q326vLya/3/

Please give me any suitable suggestions.

If you have php installed - you can use built-in server. Just open target dir with files and run

php -S localhost:8001

Okay folks, I completely understand the security reasons behind this error message, but sometimes, we do need a workaround... and here's mine. It uses ASP.Net (rather than JavaScript, which this question was based on) but it'll hopefully be useful to someone.

Our in-house app has a webpage where users can create a list of shortcuts to useful files spread throughout our network. When they click on one of these shortcuts, we want to open these files... but of course, Chrome's error prevents this.

This webpage uses AngularJS 1.x to list the various shortcuts.

Originally, my webpage was attempting to directly create an <a href..> element pointing at the files, but this produced the "Not allowed to load local resource" error when a user clicked on one of these links.

<div ng-repeat='sc in listOfShortcuts' id="{{sc.ShtCut_ID}}" class="cssOneShortcutRecord" >
    <div class="cssShortcutIcon">
        <img ng-src="{{ GetIconName(sc.ShtCut_PathFilename); }}">
    </div>
    <div class="cssShortcutName">
        <a ng-href="{{ sc.ShtCut_PathFilename }}" ng-attr-title="{{sc.ShtCut_Tooltip}}" target="_blank" >{{ sc.ShtCut_Name }}</a>
    </div>
</div>

The solution was to replace those <a href..> elements with this code, to call a function in my Angular controller...

<div ng-click="OpenAnExternalFile(sc.ShtCut_PathFilename);" >
    {{ sc.ShtCut_Name }}
</div>

The function itself is very simple...

$scope.OpenAnExternalFile = function (filename) {
    //
    //  Open an external file (i.e. a file which ISN'T in our IIS folder)
    //  To do this, we get an ASP.Net Handler to manually load the file, 
    //  then return it's contents in a Response.
    //
    var URL = '/Handlers/DownloadExternalFile.ashx?filename=' + encodeURIComponent(filename);
    window.open(URL);
}

And in my ASP.Net project, I added a Handler file called DownloadExternalFile.aspx which contained this code:

namespace MikesProject.Handlers
{
    /// <summary>
    /// Summary description for DownloadExternalFile
    /// </summary>
    public class DownloadExternalFile : IHttpHandler
    {
        //  We can't directly open a network file using Javascript, eg
        //      window.open("\\SomeNetworkPath\ExcelFile\MikesExcelFile.xls");
        //
        //  Instead, we need to get Javascript to call this groovy helper class which loads such a file, then sends it to the stream.  
        //      window.open("/Handlers/DownloadExternalFile.ashx?filename=//SomeNetworkPath/ExcelFile/MikesExcelFile.xls");
        //
        public void ProcessRequest(HttpContext context)
        {
            string pathAndFilename = context.Request["filename"];               //  eg  "\\SomeNetworkPath\ExcelFile\MikesExcelFile.xls"
            string filename = System.IO.Path.GetFileName(pathAndFilename);      //  eg  "MikesExcelFile.xls"

            context.Response.ClearContent();

            WebClient webClient = new WebClient();
            using (Stream stream = webClient.OpenRead(pathAndFilename))
            {
                // Process image...
                byte[] data1 = new byte[stream.Length];
                stream.Read(data1, 0, data1.Length);

                context.Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}", filename));
                context.Response.BinaryWrite(data1);

                context.Response.Flush();
                context.Response.SuppressContent = true;
                context.ApplicationInstance.CompleteRequest();
            }
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }

And that's it.

Now, when a user clicks on one of my Shortcut links, it calls the OpenAnExternalFile function, which opens this .ashx file, passing it the path+filename of the file we want to open.

This Handler code loads the file, then passes it's contents back in the HTTP response.

And, job done, the webpage opens the external file.

Phew ! Again - there is a reason why Chrome throws this "Not allowed to load local resources" exception, so tread carefully with this... but I'm posting this code just to demonstrate that this is a fairly simple way around this limitation.

Just one last comment: the original question wanted to open the file "C:\002.jpg". You can't do this. Your website will sit on one server (with it's own C: drive) and has no direct access to your user's own C: drive. So the best you can do is use code like mine to access files somewhere on a network drive.

1) Open your terminal and type

npm install -g http-server

2) Go to the root folder that you want to serve you files and type:

http-server ./

3) Read the output of the terminal, something kinda http://localhost:8080 will appear.

Everything on there will be allowed to be got. Example:

background: url('http://localhost:8080/waw.png');

Chrome specifically blocks local file access this way for security reasons.

Here's a workaround to enable the flag in Chrome (and open your system up to vulnerabilities):

c:\Program Files (x86)\google\chrome\Application\chrome.exe --allow-file-access-from-files

This issue come when I am using PHP as server side language and the work around was to generate base64 enconding of my image before sending the result to client

$path = 'E:/pat/rwanda.png';
$type = pathinfo($path, PATHINFO_EXTENSION);
$data = file_get_contents($path);
$base64 = 'data:image/' . $type . ';base64,' . base64_encode($data);

I think may give someone idea to create his own work around

Thanks

You just need to replace all image network paths to byte strings in stored Encoded HTML string. For this you required HtmlAgilityPack to convert Html string to Html document. https://www.nuget.org/packages/HtmlAgilityPack

Find Below code to convert each image src network path(or local path) to byte sting. It will definitely display all images with network path(or local path) in IE,chrome and firefox.

string encodedHtmlString = Emailmodel.DtEmailFields.Rows[0]["Body"].ToString();

// Decode the encoded string.
StringWriter myWriter = new StringWriter();
HttpUtility.HtmlDecode(encodedHtmlString, myWriter);
string DecodedHtmlString = myWriter.ToString();

//find and replace each img src with byte string
HtmlDocument document = new HtmlDocument();
document.LoadHtml(DecodedHtmlString);
document.DocumentNode.Descendants("img")
    .Where(e =>
    {
        string src = e.GetAttributeValue("src", null) ?? "";
        return !string.IsNullOrEmpty(src);//&& src.StartsWith("data:image");
    })
    .ToList()
    .ForEach(x =>
        {
        string currentSrcValue = x.GetAttributeValue("src", null);                                
        string filePath = Path.GetDirectoryName(currentSrcValue) + "\\";
        string filename = Path.GetFileName(currentSrcValue);
        string contenttype = "image/" + Path.GetExtension(filename).Replace(".", "");
        FileStream fs = new FileStream(filePath + filename, FileMode.Open, FileAccess.Read);
        BinaryReader br = new BinaryReader(fs);
        Byte[] bytes = br.ReadBytes((Int32)fs.Length);
        br.Close();
        fs.Close();
        x.SetAttributeValue("src", "data:" + contenttype + ";base64," + Convert.ToBase64String(bytes));                                
    });

string result = document.DocumentNode.OuterHtml;
//Encode HTML string
string myEncodedString = HttpUtility.HtmlEncode(result);

Emailmodel.DtEmailFields.Rows[0]["Body"] = myEncodedString;

This solution worked for me in PHP. It opens the PDF in the browser.

// $path is the path to the pdf file
public function showPDF($path) {
    if($path) {
        header("Content-type: application/pdf");
        header("Content-Disposition: inline; filename=filename.pdf");
        @readfile($path);
    }
}

Chrome and other Browser restrict the access of a server to local files due to security reasons. However you can open the browser in allowed access mode. Just open the terminal and go to the folder where chrome.exe is stored and write the following command.

chrome.exe --allow-file-access-from-files

Read this for more details

This way, However, didn't work for me so I made a different route for every file in a particular directory. Therefore, going to that path meant opening that file.

function getroutes(list){ 
    list.forEach(function(element) { 
        app.get("/"+ element, function(req, res) { 
            res.sendFile(__dirname + "/public/extracted/" + element); 
       }); 
   }); 
}

I called this function passing the list of filename in the directory __dirname/public/extracted and it created a different route for each filename which I was able to render on server side.

Google Chrome does not allow to load local resources because of the security. Chrome need http url. Internet Explorer and Edge allows to load local resources, but Safari, Chrome, and Firefox doesn't allows to load local resources.

Go to file location and start the Python Server from there.

python -m SimpleHttpServer

then put that url into function:

function run(){
var URL = "http://172.271.1.20:8000/" /* http://0.0.0.0:8000/ or http://127.0.0.1:8000/; */
window.open(URL, null);
}

If you could do this, it will represent a big security problem, as you can access your filesystem, and potentially act on the data available there... Luckily it's not possible to do what you're trying to do.

If you need local resources to be accessed, you can try to start a web server on your machine, and in this case your method will work. Other workarounds are possible, such as acting on Chrome settings, but I always prefer the clean way, installing a local web server, maybe on a different port (no, it's not so difficult!).

See also:

• Open local files(file://) using Chrome
• Opening local files from chrome

There is a workaround using Web Server for Chrome.
Here are the steps:

1. Add the Extension to chrome.
2. Choose the folder (C:\images) and launch the server on your desired port.

Now easily access your local file:

function run(){
   // 8887 is the port number you have launched your serve
   var URL = "http://127.0.0.1:8887/002.jpg";

   window.open(URL, null);

}
run();

PS: You might need to select the CORS Header option from advanced setting incase you face any cross origin access error.

I've encounterd this problem, and here is my solution for Angular, I wrapped my Angular's asset folder in encodeURIComponent() function. It worked. But still, I'd like to know more about the risk of this solution if there's any:

```const URL = ${encodeURIComponent(/assets/office/file_2.pdf)} window.open(URL)

I used Angular 9, so this is my url when I clicked open local file:
```http://localhost:4200/%2Fassets%2Foffice%2Ffile_2.pdf```

You won't be able to load an image outside of the project directory or from a user level directory, hence the "cannot access local resource warning".

But if you were to place the file in a root folder of your project like in {rootFolder}\Content\my-image.jpg and referenced it like so:

<img src="/Content/my-image.jpg" />