ImageClassifier does not throw an error when image is not found

[hx2A]

When I follow the example on the Hello ml5 page:

https://ml5-website-2.netlify.com/getting-started/hello-ml5/

If the image to be classified is not found, p5's loadImage function will fail and log an error in the console. The img variable will not contain a valid image.

When classifier.classify(img, gotResult); is called in the setup method it should trigger an error because the image is not valid. However, in the gotResult method, this code:

  if (error) {
    console.error(error);
  }

is not executed. The error you see logged in the console is from p5, not ml5. If I change the function to this:

// A function to run when we get any errors and the results
function gotResult(error, results) {
  // Display error in the console
  if (error) {
    console.error(error);
    console.log('error');
    createDiv('Error running image classifier. View JavaScript console for details.');
  } else {
    // The results are in an array ordered by confidence.
    console.log(results);
    console.log('no error');
    createDiv('Label: ' + results[0].label);
    createDiv('Confidence: ' + nf(results[0].confidence, 0, 2));
  }
}

I see no error in the console.

Chromium Version 73.0.3683.103 (Official Build) Built on Ubuntu , running on Ubuntu 19.04 (64-bit) using ml5 0.3.0.

You can reproduce this by following the Getting Started tutorial but use an invalid image path.

[lindapaiste]

There is more discussion of this issue in #1193. The changes to callCallback in #1307 should help.

I will take a look and make sure that we are throwing an appropriate error when passing in a p5 image which has failed to load.