Vega: Problem with embed.js

[malhotrachetan]

I am trying to load this web page containing vega view using this server script:

The testgram.html goes like:

But the chrome console throws an exception:

What could be the problem? is there a problem with my code or with vega-embed.js?

[jheer]

It looks like non-JSON data is being passed into JSON.parse. I would check the content of testgram.json and then check if it is being loaded correctly. By passing in a string name only (no URL protocol or directory) it should be looking for that file at the same directory location as testgram.html.

[malhotrachetan]

Hey! Thanks for the reply. So, vega.embed() works now when passed url: https://raw.githubusercontent.com/histogrammar/histogrammar-python/vega/histogrammar/plot/vega/testgram/testgram.json

Thanks for the help.

[malhotrachetan]

So vega.embed() will load a vega specification from remote server only? I can't load local vega specifications?

[domoritz]

@debuggermalhotra, no, you can load a local spec (either via URL or as object). Detailed docs are at https://github.com/vega/vega-embed.

[jheer]

A single file (such as blah.vg.json) should be treated as a URL without a specified protocol (default is http://) or directory (default is the same directory as the calling web page). In your case I suspect the error arose due to trying to access a file that does not exist at the default location, followed by a failure to parse the returned 404 page (hence the failure of JSON parsing on the initial < character). But that is just a guess.

In any case, vega-embed should provide better error handling for load failures, and I've opened a new issue for that.