做的两种方式：

app.directive('parseUrl', function () {
    var urlPattern = /(http|ftp|https):\/\/[\w-]+(\.[\w-]+)+([\w.,@?^=%&:\/~+#-]*[\w@?^=%&\/~+#-])?/gi;
    return {
        restrict: 'A',
        require: 'ngModel',
        replace: true,
        scope: {
            props: '=parseUrl',
            ngModel: '=ngModel'
        },
        link: function compile(scope, element, attrs, controller) {
            scope.$watch('ngModel', function (value) {
                var html = value.replace(urlPattern, '<a target="' + scope.props.target + '" href="$&">$&</a>') + " | " + scope.props.otherProp;
                element.html(html);
            });
        }
    };
});

HTML

<p parse-url="props" ng-model="text"></p>

过滤器

app.filter('parseUrlFilter', function () {
    var urlPattern = /(http|ftp|https):\/\/[\w-]+(\.[\w-]+)+([\w.,@?^=%&:\/~+#-]*[\w@?^=%&\/~+#-])?/gi;
    return function (text, target, otherProp) {
        return text.replace(urlPattern, '<a target="' + target + '" href="$&">$&</a>') + " | " + otherProp;
    };
});

HTML

<p ng-bind-html-unsafe="text | parseUrlFilter:'_blank':'otherProperty'"></p>

注：'otherProperty 是只是举例，如果你想通过更多的属性进入过滤器

Note: The 'otherProperty' is just for example, in case you want to pass more properties into the filter.

的jsfiddle

jsFiddle

更新：更换改进算法