JsxGraph from Dart using Dart JS interop - dart

Question

I am trying to use the plotting library JSXGraph from Dart using dart js but I have problems.
This is working javascript code
var board = JXG.JSXGraph.initBoard(
'box',
{
boundingbox: [-10, 10, 2, -1],
axis: true,
keepaspectratio: false,
showNavigation: false
}
);
var graph = board.create(
'functiongraph',
[function(x){ return 3*x*x + 5*x + 1;}, -10, 10],
{strokeColor: '#ffff00'}
);
You can try it here on jsFiddle.
I want to do basically the identicall thing but from dart. This is what I have come up with so far:
JsObject jsxGraph = context['JXG']['JSXGraph'];
var board = jsxGraph.callMethod('initBoard', [
'box',
new JsObject.jsify({
'boundingbox': [-10, 10, 2, -1],
'axis': true,
'keepaspectratio': false,
'showNavigation': false
})
]);
var graph = board.callMethod('create', [
'functiongraph',
[(x){return 3*x*x + 5*x + 1;}, -10, 10],
new JsObject.jsify({'strokeColor': '#ffff00'})
]);
I get the plot area and axes but I can't get the actual plot line. Instead, there is an error on the console: Uncaught TypeError: this.Y is not a function.
Could someone, please, point me to what I could be doing wrong? I suspect it is something about the callback function but I really don't know what.

Answer 1

There's a jsify missing in your code:
JsObject jsxGraph = context['JXG']['JSXGraph'];
var board = jsxGraph.callMethod('initBoard', [
'box',
new JsObject.jsify({
'boundingbox': [-10, 10, 2, -1],
'axis': true,
'keepaspectratio': false,
'showNavigation': false
})
]);
var graph = board.callMethod('create', [
'functiongraph',
new JsObject.jsify([(x){return 3*x*x + 5*x + 1;}, -10, 10]},
new JsObject.jsify({'strokeColor': '#ffff00'})
]);