Visualization with JavaScript of data from a JSON source?

I would like to use a library like the Google Visualization API to draw charts, but taking the data as JSON from an external source. The context is to use some SPARQL service to extract the data from a XHTML+RDFa source, as described here. But that latter page has to use a trick, b开发者_JS百科ut points out that it would be great that these visualization toolkits can take data input directly from JSON returned by some web page.

Is there a chart visualization library that supports taking the data it visualizes directly from a JSON-returning URL?

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Take a look at Highcharts. In one of their examples, jQuery.getJSON() is employed to fetch data as JSON. For external URLs, there may be an issue with the same origin policy, unless the external service has JSONP callbacks.