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.