$http.get('/paste/' + $scope.paste).success(getCallback);

var getCallback = function(data) {
    setTimeout(function() {
        $scope.paste = data[0].code;
        $scope.$apply();
    }, 0);
};

app.filter('pretty', function() {
    return function(text) {
        // a method in the prettify.js
        return prettyPrintOne(text, '', true);
    };
});

<pre ng-bind-html="paste|pretty"></pre>