About File And Folder Operations

About File and Folder Operations

File Download

Clients may call getDownloadUrl which returns a URL that can be invoked at a later time.

getDownloadUrl

Call getDownloadUrl to retrieve a URL hat can be invoked at a later time.

Code Sample

var url = cloud.getDownloadUrl('/path/to/file.jpg');
//Use jQuery to set a hyperlink dynamically
$('a').attr('href',url);
```	

## File Upload

While uploading files which are only a few hundred of kilobytes in size on a standard connection typically does not pose any difficulties, this often might not be the case for your users. Your app should be able to upload large files, such as videos efficiently. It should also be able to recover from interrupted uploads that might be caused by mobile connectivity issues or power outages, without having to restart the upload process.

Chunked file uploads allow you to break a large file into small chunks, and then send these pieces to the upload server one-by-one. If an upload were to fail, your app would not have to resend the whole file. It can resume the file upload from the last successfully sent chunk.

**NOTE:**  
You cannot perform the file upload operation on a [virutal folder](../../API_Developer_Guide/About_Virtual_Folders/). 

### Non-Chunked File Upload

1. Call [`fileuploadIntent`](../../Node.js_Reference/File_and_Folder_Operations/) to let the system know that you intend to upload a file. Set the `chunk` parameter to *false*.
2. Upload the file using the library of your choice.

**Code Sample**
    
```javascript
cloud.fileuploadIntent({
    checksum: sha256, //sha256 checksum of the file
    chunk: false,
    name: 'somefile.txt',
    path: '/VZMOBILE/someDirectory', 
    size: file.size,
    success: function(success) {
        var uploadUrl = success.body.uploadurls.uploadurl;
        //now actually upload the file using the library of your choice
        Upload.http({
            url: uploadUrl + "&checksum=" + encodeURIComponent(sha256),
            data: file, 
            headers: {
                'Authorization': 'Bearer ' + cloud.getAuth().authToken,
                'Content-Type': 'application/octet-stream' 
            },
        })
    }
});

Chunked File Upload

Call fileuploadIntent to let the system know that you intend to upload a file. Set the chunk parameter to true.
Upload the file using the library of your choice.
Call commitChunkedUpload to finalize the chunked file upload.

Code Sample

cloud.fileuploadIntent({
    checksum: sha256, //sha256 checksum of the file
    chunk: true, //note chunk is set to true
    name: 'somefile.txt',
    path: '/VZMOBILE/someDirectory', 
    size: file.size,
    success: function(success) {
        var uploadUrl = success.body.uploadurls.uploadurl;
        //used to tell the server you're done uploading chunks
            var commiturl = success.body.uploadurls.commiturl; 
    
        //Upload the file in chunks using the library of your choice
        var chunksUploaded = 0;
        for(var c = 1; c <= numberOfChunks; c++) {
            Upload.http({
                url: uploadUrl + "&checksum=" + encodeURIComponent(sha256),
                data: getChunk(file, c),   
                headers: {
                    'Authorization': 'Bearer ' + cloud.getAuth().authToken,
                    'Content-Type': 'application/octet-stream' 
                },
            }).then(function(resp) {
                chunksUploaded++;
                //Once all chunks have been uploaded, finalze the chunked file upload.
                if(chunksUploaded == numberOfChunks) {
                    cloud.commitChunkedUpload({
                        commiturl: commiturl,
                        success: function(success) {
                            //done uploading in chunks
                            }
                    });
                }
            });
        }
});

Fullview

You can call fullview method to download the information on all files and folders within a user’s Personal Cloud Storage account.

A successful cal to fullview returns an ‘x-header-etag’. You can use the ‘x-header-etag’ to retrieve the changes to the files and folders made between two fullview calls.

fullview

The following code sample shows a call to fullview.

Code Sample

cloud.fullview({
    success: function(success) {
            var files = success.body.data.file;
            var folders = success.body.data.folder;
            var etag = success.headers['x-header-etag'];
    }
});

fullview with Delta

The following code sample uses the ‘x-header-etag’ retrieved from a previous fullview call. The result of this call is the information on all files and folders that have been changed since the previous fullview call.

Code Sample

cloud.fullview({
    etag: etag, // retrieved from previous fullview call
    success: function(success) {
            var filesDelta = success.body.data.file;
            var foldersDelta = success.body.data.folder;
            //the new etag should be passed into subsequent fullviews
            var newEtag = success.headers['x-header-etag'];
    }
});

Thumbnails

You can download thumbnails of a file by calling getThumbnailUrl method.

getThumbnailUrl

To retrieve thumbnail of a file, you will need to provide the file’s contentToken. The content token is contained in the response to a call to fullview or metadata API.

Code Sample

var size = 32; //width and height of the thumbnail in pixels
//you can retrieve the contentToken from any fullview or metadata call;
var thumbnailUrl = cloud.getThumbnailUrl(contentToken, size);