У Дэвида Уолша есть руководство по использованию API веб-шрифтов Google здесь: http://davidwalsh.name/google-fonts-api
Вот пример из его поста:
WebFontConfig = {
google: {
families: [ 'Tangerine', 'Cantarell' ]
},
/* Called when all the specified web-font provider modules (google, typekit, and/or custom) have reported that they have started loading fonts. */
loading: function() {
// do something
},
/* Called when each requested web font has started loading. The fontFamily parameter is the name of the font family, and fontDescription represents the style and weight of the font. */
fontloading: function(fontFamily, fontDescription) {
// do something
},
/* Called when each requested web font has finished loading. The fontFamily parameter is the name of the font family, and fontDescription represents the style and weight of the font. */
fontactive: function(fontFamily, fontDescription) {
// do something
},
/* Called if a requested web font failed to load. The fontFamily parameter is the name of the font family, and fontDescription represents the style and weight of the font. */
fontinactive: function(fontFamily, fontDescription) {
// do something
},
/* Called when all of the web fonts have either finished loading or failed to load, as long as at least one loaded successfully. */
active: function() {
// do something
},
/* Called if the browser does not support web fonts or if none of the fonts could be loaded. */
inactive: function() {
// do something
}
};
/* async! */
(function() {
var wf = document.createElement('script');
wf.src = ('https:' == document.location.protocol ? 'https' : 'http') + '://ajax.googleapis.com/ajax/libs/webfont/1/webfont.js';
wf.type = 'text/javascript';
wf.async = 'true';
var s = document.getElementsByTagName('script')[0];
s.parentNode.insertBefore(wf, s);
})();