Convert Blob to File and preview on browser (not download)

Question

I am getting a Blob content from webservice callout and requirement is to display the file in browser.

What I have:

• Blob file (fileBlob)

Above blob parameter I get as response and sending same back to javascript method in "callback". I am trying to convert the blob to respective file format and view on browser (I dont want to download unless enduser wants so).

I tried below:

    var callback1 = { 
        onSuccess: function(e){ //e is the blob content I am receiving
            alert('Receiving file from SF:---> ' + e);
            var file = new File([e], "uploaded_file.pdf", { type: "application/pdf", lastModified: Date.now() });
            //document.body.append(file);
            //var blob=new Blob([e], {type:"application/pdf"});
            var link=document.createElement('a');
            //link.href=window.URL.createObjectURL(e);
            link.download=file;
            link.click();                

        }, onFailure: function(error){
            alert(error);   
        } 
    };

Update

Update 2 (after treating response as base64)

Solution

Make use of iframe to display pdf file, the function would look like this with blob response and file name.

   function openPDF(resData, fileName) {
            var ieEDGE = navigator.userAgent.match(/Edge/g);
            var ie = navigator.userAgent.match(/.NET/g); // IE 11+
            var oldIE = navigator.userAgent.match(/MSIE/g); 
            var bytes = new Uint8Array(resData); //use this if data is raw bytes else directly pass resData
            var blob = new window.Blob([bytes], { type: 'application/pdf' });

            if (ie || oldIE || ieEDGE) {
               window.navigator.msSaveBlob(blob, fileName);
            }
            else {
               var fileURL = URL.createObjectURL(blob);
               var win = window.open();
               win.document.write('<iframe src="' + fileURL + '" frameborder="0" style="border:0; top:0px; left:0px; bottom:0px; right:0px; width:100%; height:100%;" allowfullscreen></iframe>')

            }
        }

Comments

[sf_user]

Thanks Krishna. This seems to work but as soon as pdf loads, browser tab refreshes to home page. I tried adding return false in your method but that didnt help either, any idea ?

[KrishnaSingh]

I have updated the code, enrich your blob data with Uint8Array. If you still have problem share your blob data sample.

[sf_user]

I was getting "Cannot read property of document null" and then changed last line to window,document.write instead of win.document.write. Now after I get the response, tab opens as pdf but gives error Failed to load pdf document updated my question with error screen shot and also the blob I am receiving from service

[KrishnaSingh]

Try the new updated code, it should work I suspect your response is raw bytes array. Enrich your data first with var bytes = new Uint8Array(resData);

[KrishnaSingh]

Your response seems like its's base64 format so u can try win.document.write('<iframe src="data:base64' + resData + '" frameborder="0" style="border:0; top:0px; left:0px; bottom:0px; right:0px; width:100%; height:100%;" allowfullscreen></iframe>') ;

[KrishnaSingh]

Let us continue this discussion in chat.

[sf_user]

I am positive its blob as my return type in server side method is blob. However I tried to use the above one u mentioned (base64) and I am getting page as shown in screenshot (updated in question)

[sf_user]

Thanks Krishna for helping me with this. stackoverflow.com/questions/40674532/…

[Yaje]

Will this be possible for blob types application/vnd.ms-excel and application/msword