SharePoint Online - Create a SharePoint Group dynamically based on the permission type to all SharePoint Sites

Scenario - Suppose you have a SharePoint site collection and you would like to add a new group to all sites and sub-sites (Unique Permissions). 

The following code creates a group to all sites based on the permission type and name it with "SITENAME_PERMISSION". You can change it to any parameter.

using (ClientContext clientContextSub = new ClientContext(strSiteUrl))

            {

                SecureString passWord = new SecureString();

                foreach (char c in password.ToCharArray()) passWord.AppendChar(c);

     clientContextSub.Credentials = new SharePointOnlineCredentials(userName, passWord);

                clientContextSub.ExecuteQuery();

                try

                {

                 Web webSubWeb = clientContextSub.Web;

                 GroupCollection groupCollection = webSubWeb.SiteGroups;

                 clientContextSub.Load(webSubWeb.RoleAssignments);

                 clientContextSub.Load(

                 webSubWeb,

                   web2SubWebSubNode => web2SubWebSubNode.Title,

                   web2SubWebSubNode => web2SubWebSubNode.Url,

                   web2SubWebSubNode => web2SubWebSubNode.LastItemModifiedDate,

                   web2SubWebSubNode => web2SubWebSubNode.HasUniqueRoleAssignments);

                   clientContextSub.ExecuteQuery();

                  

                    if (webSubWeb.HasUniqueRoleAssignments)

                    {

                        bool _permissionGroupAvailable = false;

                        string _groupNameToAssign = string.Empty;

                        string groupOwener = string.Empty;

                        foreach (RoleAssignment assignment in webSubWeb.RoleAssignments)

                        {

                            try

                            {

                                string Role = string.Empty;

                                clientContextSub.Load(assignment.Member);

                                clientContextSub.Load(assignment.RoleDefinitionBindings);

                                clientContextSub.ExecuteQuery();

                    foreach (RoleDefinition roleDef in assignment.RoleDefinitionBindings)

                                {

//CMBAddGroup is selected permission type from a dropdown (Ex- Full Control, Read, Contribute)

       if (roleDef.Name.ToString().Trim() == cmbAddGroup.SelectedItem.ToString().Trim())

                                    {

                                        _permissionGroupAvailable = true;

                                        break;

                                    }

                                }

                                if (_permissionGroupAvailable)

                                { break; }

                            }

                            catch (Exception ex)

                            {

                               continue;

                            }

                        }

                        if (!(_permissionGroupAvailable))

                        {

                           

                           {

_groupNameToAssign = webSubWeb.Title + "_" + cmbAddGroup.SelectedItem.ToString();

GroupCreationInformation newGroupInfo = new GroupCreationInformation();

newGroupInfo.Title=_groupNameToAssign.ToString();

Group groupExist = webSubWeb.SiteGroups.GetByName(_groupNameToAssign);

                            if (groupExist == null)

                            {

Group oGroup = webSubWeb.SiteGroups.Add(newGroupInfo);

RoleDefinitionBindingCollection collRoleDefinitionBinding = new RoleDefinitionBindingCollection(clientContextSub);

RoleDefinition oRoleDefinition = webSubWeb.RoleDefinitions.GetByName(cmbAddGroup.SelectedItem.ToString());

collRoleDefinitionBinding.Add(oRoleDefinition);

webSubWeb.RoleAssignments.Add(oGroup, collRoleDefinitionBinding);

clientContextSub.Load(oGroup, group => group.Title);

clientContextSub.Load(oRoleDefinition,role => role.Name);

clientContextSub.ExecuteQuery();

                            }

                            else

                            {

RoleDefinitionBindingCollection collRoleDefinitionBinding = new RoleDefinitionBindingCollection(clientContextSub);

RoleDefinition oRoleDefinition = webSubWeb.RoleDefinitions.GetByName(cmbAddGroup.SelectedItem.ToString());

collRoleDefinitionBinding.Add(oRoleDefinition);

webSubWeb.RoleAssignments.Add(groupExist, collRoleDefinitionBinding);

clientContextSub.Load(groupExist, group => group.Title);

clientContextSub.Load(oRoleDefinition,role => role.Name);

clientContextSub.ExecuteQuery();

                            }

                            }

                            }

                       

                        }

                    }

            

                catch (Exception ex)

                {

                    helpClass.ErrorLog("", "Error MESSAGE: " + ex.Message);

                }

            }

        }