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Using javascript to download file from dropbox

I am creating a javascript routine that requires me to download and upload updated files in my dropbox app file folders which contains updated football picks. I am able to upload files to my app but when I try to upload I get an undefined error.

file path :

download functions (I tried both of these) :

Both of these functions return the same error :

Any assistance would be greatly appreciated. Thanks.

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amei

LoadFileFromDropbox error (other load function attempt)

DB-Des

Hi @amei

The response from 'filesDownload()' does not contain a 'fileBlob' property (which is why you are getting an 'undefined' in the error message). The response contains a 'fileBinary', which can be accessed as such: 'response.result.fileBinary'. Additionally, you can convert the returned Buffer to text or a string by invoking the 'toString()' method on the response. We would also recommend making that callback function an async function:

...
dbx.filesDownload({ path: dropbox_users_path_file })
.then(async (response) => {
  console.log(response.result.fileBinary.toString())
}
...

Similarly for the second function:

...
try {
  const response = await dbx.filesDownload({
    path: dropbox_users_path_file
  })
  console.log(response.result.fileBinary.toString())
}
...

In order to further assist with the file upload error, please provide the code snippet used to upload files to Dropbox. The screenshots provided are both for downloading files ('filesDownload()').

amei

thanks for your assistance. I updated both functions as you suggested :

Still getting the same errors :

The jason file that I have uploaded from my upload function looks like this :

It is an array of football picks. So when I upload the files I used the JSON.stringify to save the array. When I open the jason file I see text, not binary characters. Not sure if this is the problem. Perhaps a text response would ? I need to download the file back into the array (what the file is currently saved as as shown above.

I should have included this info in my initial post. I hope this provides more clarity. thanks.

amei

I updated my download function as :

I get a successful download, but I don't see the one line of football picks, just a blank array. The array is formatted correctly, but does not contain any information.

I changed fileBinary to fileText. I'm not sure if I have to define that it is a json file.

DB-Des

@amei

Could you share the actual error that is being logged onto the console? Both the top-level 'error' and the lower-level 'error.error'.

amei

Hi DB-DEs

My request is at the bottom with how to donwload a jason text file from my dropbox app to an array called users_array. Here is somebackground before the request at the bottom.

With your assistance I was able to upload a stringified Jason file to my dropbox ap. Download function below :

The uploaded jason file is a text file (not binary) and is an array of football picks as follows :

Here are the functions I tried to use to upload the file above into an array called users_array. As you can see I tried 3 different methods. The LoadFileFromDropbox function gives me a promise with the array content, just can't get the content.

amei

the LoadFromDropbox returns the following :

The LoadFromDropbox2 returns essentially the same

iNeil

Hi @amei,

I have reviewed the information you provided. From my understanding, you are experiencing difficulties downloading a file using the Dropbox JavaScript SDK and parsing a JSON file.

Based on the code snippet you shared, it appears that the JSON file is being parsed incorrectly. Would you be able to test the following code snippet example to check whether it resolves the issue you are encountering?

import { Dropbox } from "dropbox";
import fs from "fs/promises";

const dbx = new Dropbox({ accessToken: "YOUR_ACCESS_TOKEN" });

async function downloadJsonFile() {
  try {
    // Request file from Dropbox
    const { result } = await dbx.filesDownload({ path: "/users_array.json" });

    // Convert response into a buffer
    let buffer;
    if (result.fileBinary) {
      buffer = Buffer.from(result.fileBinary);
    } else if (result.fileBlob) {
      const ab = await result.fileBlob.arrayBuffer();
      buffer = Buffer.from(ab);
    } else {
      throw new Error("Unexpected response: no fileBinary/fileBlob present.");
    }

    // Download the file to a specified location on your local machine.
    await fs.writeFile("/YOUR_FILE_PATH_TO/users_array.json", buffer);
    console.log("File downloaded successfully");

    // Parsing JSON file after downloading the file
    const parsed = JSON.parse(buffer.toString("utf8"));
    console.log("Parsed JSON object:", parsed);

  } catch (error) {
    console.error(" Error downloading file:", error);
  }
}

downloadJsonFile();

amei

Thanks for pointing me in the right direction. I finally figured out that I was working with a string(text) representation of an array uploaded to dropbox as a json file. Once I realized that this is what I did to properly download the jason file and etablish the users_array containing football picks :

Array Listing : (note I only picked one line)

When I tried to call up a particular value in the array to make sure it's working :

So the array has been downloaded and formatted properly, Thanks for pointing me in the right direction.

The only issue I have now is that I have been working with a temporary access code (starts with sl and lasts only 4 hours). Is there an option to make the code last for a week or more ?

iNeil

Hi @amei, I'm happy to hear that you are able to resolve the issue with downloading the JSON file with the Dropbox API!

In relation to the access token, it's not possible to extend the access token's expiry time. Please bear in mind that Dropbox is no longer offering the option for creating new long-lived access tokens. Dropbox is now issuing short-lived access tokens (and optional refresh tokens) instead of long-lived access tokens. You can find more information on this migration here.

Apps can still get long-term access by requesting "offline" access though, in which case the app receives a "refresh token" that can be used to retrieve new short-lived access tokens as needed, without further manual user intervention. Refresh tokens do not expire automatically and can be used repeatedly. You can find more information in the OAuth Guide and authorization documentation. There's a basic outline of processing this flow in this blog post which may serve as a useful example.

amei

Hi INeil. As I mentioned previously I was able to download the dropbox jason file and parse it into and array inside the async function shown below. However when I try to use it outside the async function it is either returned as undefined or a promise. Below are more detials.

Load file from dropbox and parse the array. Works fine within this async function.

Results : within function (listed as local) the array works fine, outside function (listed as global), a promise is returned and the array is undefined. Any assistance with using this array outside of the async function would be greatly appreciated.

James_David

The Dropbox Python SDK can fail to download complete files in Pyodide or xlwings lite. A workaround is to call the Dropbox API for a temporary link and then fetch that link with pyfetch. For example, use files/get_temporary_link to get the URL, then call pyfetch(link, method="GET") and use res.bytes() to get the full file. Uploads with the SDK usually work fine, but for downloads this direct fetch method avoids incomplete files.

amei

One more issue I am trying to resolve. As I mentioned previously I was able to download the file from dropbox and properly parse it into an array and access array elements within the async function I use to download the dropbox file. However I am having issues using the array outside of the async function LoadFileFromDropBox. It looks like it returns a promise not an array I can use outside the function. I have tried a few things get the array from the returned promise but unsuccessful. Here is the functions I am trying to work with :

I have tried various calls to try to access the array outside the async function :

The usual results I get on the console is as follows :

Any assistance to be able to use the users_array outside of the async functions would be greatly appreciated. Thanks.

DB-Des

@amei

Could you provide the whole code snippet so we can test it on our end?