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标签： user role

  • Dynamic Tree Construction according to User Role and Page

    In the developing environment of C# and .NET, dynamic data binding isn’t anything new at all. I’m here just to make a summary of how to do the job to a TreeView object, and add a few contents depending on my practical experience.

    Keywords: dynamic tree construction, user role, page.

    Problem Description

    In the classic three-layer architecture adopted by my project, we have

    1. data tables that are dealt with by a DAL-located class database.cs;

    2. a series of corresponding BLL classes to manipulate data retrieved from those tables;

    3. aspx pages and aspx.cs code files in the presentation layer.

    which means following elements are involved:

    1. data table User, UserRole, RoleTree;

    2. class User.cs, UserRole.cs, RoleTree.cs;

    3. example page sampleTree.aspx and its code file sampleTree.aspx.cs.

    A picture speaks more than a thousand words. Let’s first take a look at the chart below to get an overview of how this work is going to be done.

    Solution Pt1: User Login

    By the input username and password, we first get the userId, through which user role(s) are obtained and stored in a Session object. In case of more than one role for a specific user, we take an ArrayList as the role container.

    if (Page.IsValid)
    {
        User usr = new User();
        string userId = "";
        SqlDataReader recs = usr.GetUserLogin(txtUserName.Text.Trim(), txtPassword.Text.Trim());

        if (recs.Read())
        {
            userId = recs["UserID"].ToString();
        }
        recs.Close();

        if ((userId != String.Empty) && (userId != ""))
        {
            // get user roles, put them into session
            ArrayList alRoleIDs = new ArrayList();
            UserRole ur = new UserRole();
            SqlDataReader dr = ur.GetRoleByUserID(Int32.Parse(userId));
            while (dr.Read())
            {
                alRoleIDs.Add(Int32.Parse(dr["RoleID"].ToString()));
            }
            Session.Add("RoleIDs", alRoleIDs);
            dr.Close();
        }

    Solution Pt2: Tree Construction

    Then we take the RoleIDs of ArralyList above and some PageID of int as arguments to get the tree. Codes below are sample codes from sampleTree.aspx.cs:

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            BindTreeData(treeSidebar, (ArrayList)Session["RoleIDs"]);
        }
    }

    private void BindTreeData(TreeView tv, ArrayList al)
    {
        RoleTree rt = new RoleTree();
        // when applied to different pages, take RoleIDs of ArrayList and PageID of int as arguments
        DataTable dt = rt.GetTreeByRoleIDandPageID(al, 3); // 3 is an exmaple of pageId
        tv.Nodes.Clear();

        foreach (DataRow row in dt.Select())
        {
            TreeNode tempNode = new TreeNode();
            tempNode.Text = row["Title"].ToString();
            tempNode.Value = row["NodeID"].ToString();
            tempNode.Expanded = false;
            tempNode.NavigateUrl = row["Url"].ToString();

            tv.Nodes.Add(tempNode);
        }
    }

    Further Notice

    //It is especially useful when applied to MasterPages.

    //This solution does not take node’s parent into account, which means the TreeView object constructed is not a real tree, strictly speaking.