Add/Remove/Check Current User Against a Specific Group

//Check if current user is in a specific group

function isCurrentUserInGroup(groupId, funUserInGroup, funUserNotInGroup, funOnError) {

    var ctx = new SP.ClientContext.get_current();

    var currentUser = ctx.get_web().get_currentUser();

    ctx.load(currentUser, 'Id', 'LoginName');

    var group = ctx.get_web().get_siteGroups().getById(groupId);

    var users = group.get_users();

    ctx.load(users);

 

    ctx.executeQueryAsync(function (sender, args) {

        //See whether the user exists

        var userFound = false;

        var userEnumerator = users.getEnumerator();

        while (userEnumerator.moveNext() && !userFound) {

            var user = userEnumerator.get_current();

            if (user.get_id() == currentUser.get_id()) {

                //User exists in the group

                userFound = true;

                if (funUserInGroup != null)

                    funUserInGroup();

            }

        }

        //User doesn't exist in the group

        if (!userFound && (funUserNotInGroup != null))

            funUserNotInGroup();

 

    }, function (sender, args) {

        if (funOnError != null)

            funOnError(sender, args);

    });

}

 

//Add current user to specific group

function addCurrentUserToGroup(groupId, funOnSuccess, funOnError) {

    var ctx = new SP.ClientContext.get_current();

    var currentUser = ctx.get_web().get_currentUser();

    ctx.load(currentUser);

    var group = ctx.get_web().get_siteGroups().getById(groupId);

    ctx.load(group);

    group.get_users().addUser(currentUser);

 

    ctx.executeQueryAsync(function (sender, args) {

        if (funOnSuccess != null)

            funOnSuccess(sender, args);

    }, function (sender, args) {

        if (funOnError != null)

            funOnError(sender, args);

    });

}

 

//Remove current user from specific group

function removeCurrentUserFromGroup(groupId, funOnSuccess, funOnError) {

    var ctx = new SP.ClientContext.get_current();

    var currentUser = ctx.get_web().get_currentUser();

    ctx.load(currentUser);

    var group = ctx.get_web().get_siteGroups().getById(groupId);

    ctx.load(group);

    group.get_users().remove(currentUser);

 

    ctx.executeQueryAsync(function (sender, args) {

        if (funOnSuccess != null)

            funOnSuccess(sender, args);

    }, function (sender, args) {

        if (funOnError != null)

            funOnError(sender, args);

    });

}