Dropzone: prevent uploading of duplicate files

Question

I am using Dropzone. I\'d like to prevent the uploading of a file which already exists as thumbnail in Dropzone \"panel\". With uploading I mean not to allow a file with the

Answer 1

Here is the solution I came to:

Add these two options in your Dropzone initialization

dictDuplicateFile: "Duplicate Files Cannot Be Uploaded",

preventDuplicates: true,

and add one more prototype function and re-implement your dropzone addFile prototype function above dropzone initialization like this:

Dropzone.prototype.isFileExist = function(file) {
      var i;
      if(this.files.length > 0) {
        for(i = 0; i < this.files.length; i++) {
          if(this.files[i].name === file.name 
            && this.files[i].size === file.size 
            && this.files[i].lastModifiedDate.toString() === file.lastModifiedDate.toString())
           {
               return true;
           }
        }
      }
      return false;
    };

Dropzone.prototype.addFile = function(file) {
      file.upload = {
        progress: 0,
        total: file.size,
        bytesSent: 0
      };
      if (this.options.preventDuplicates && this.isFileExist(file)) {
        alert(this.options.dictDuplicateFile);
        return;
      }
      this.files.push(file);
      file.status = Dropzone.ADDED;
      this.emit("addedfile", file);
      this._enqueueThumbnail(file);
      return this.accept(file, (function(_this) {
        return function(error) {
          if (error) {
            file.accepted = false;
            _this._errorProcessing([file], error);
          } else {
            file.accepted = true;
            if (_this.options.autoQueue) {
              _this.enqueueFile(file);
            }
          }
          return _this._updateMaxFilesReachedClass();
        };
      })(this));
    };

You can also modify your drozone file if you want.

Answer 2

Add these simple lines of code:

myDropzone.on("addedfile", function(file) {
    if (this.files.length) {
        var _i, _len;
        for (_i = 0, _len = this.files.length; _i < _len - 1; _i++) // -1 to exclude current file
        {
            if(this.files[_i].name === file.name && this.files[_i].size === file.size && this.files[_i].lastModifiedDate.toString() === file.lastModifiedDate.toString())
            {
                this.removeFile(file);
            }
        }
    }
});

Answer 3

I'm checking from the server if the file is duplicate and then returning the error to dropzone,ee below:

 $targetPath = '/tmp/my_dropzone_files';
 $image_name = $_FILES['file']['name'];
 $targetFile =  $targetPath . '/' . $image_name; 

        $file_exists = file_exists ( $targetFile );

        if( !$file_exists ) //If file does not exists then upload
        {
            move_uploaded_file( $tempFile, $targetFile );
        }
        else //If file exists then echo the error and set a http error response
        {
            echo 'Error: Duplicate file name, please change it!';
            http_response_code(404);
        }

Answer 4

The following solution helped me:

this.on('addedfile', function(file) {
    setTimeout(function() { 
        $(".dz-file-preview").remove(); // removes all files except images
    }, 3000);
});