HIghcharts, button text undefined

Question

I've trawled through the API and can't find where to define the alt text of custom nav buttons.

Can anyone help out?

Here's a sample of what I've got in my exporting options:

exporting: {
    buttons: {
        contextButtons: {
            enabled: false,
            menuItems: null
        },
        contextButton: {
            menuItems: null,
            symbol: 'url()',
            symbolX: 1,
            symbolY: 1,
            width: 1,
            height:1,
            onclick: function() {
                return false;
            }
        },
        'downButton': {
            symbol: 'url(img/glyphicons/glyphicons_200_download.png)',
            symbolX: 13,
            symbolY: 13,
            width: 26,
            height:26,
            onclick: function() {
                this.exportChart();
            }
        }
    },
    type: 'image/png'
},

Answer 1

_titleKey is what you want. See http://jsfiddle.net/x36qR/1/ for an example.

Answer 2

make sure you define lang: { } parameter in the chart object

then use the _titleKey: "example" in the lang to set the desired title

  .highcharts({

        lang:{
            example: "Title Name"
        },