Friday, October 14, 2011

Personal .NET Portal


Introduction

This article describes how I build my Personal Portal (in other words: a Homepage). The idea was to develop a Portal that is easy to deploy (e.g. no Database) and easy to use.
These technical problems are solved in this solution
  • Storage The portal doesn't use a database. Instead XML-Files are used. Reading/Writing is done with the XML Serializer and Datasets.
  • Dynamically loading of Web User Controls The portal has Tabs and Modules. Modules are Web User Controls which are loaded at runtime. The definition is stored in a XML File.
  • Authentication Forms Authentication is used. Users and Roles are stored in a XML File.
  • HttpHandler A HttpHandler is used to access Tab-Pages.

Background

First I wanted to use the IBuySpy Portal. But it isn't (or wasn't) free and uses a database. After some searching at Codeproject and Sourceforge I decided to implement my own Portal.
This Project is hosted at Sourceforge. I would be happy about feedback and suggestions . Also new modules or improvements are welcome. A Demo Portal can be found here .

Using the code

Feel free to use the Portal under the GPL License or code snippets freely.

Summary

A Portal has Tabs. Each Tab can have Sub-Tabs and Modules. Modules are providing content. A Module can be placed right, in the middle or on the left side on a Tab.
A Module consists of a View Web User Control and a Edit Web User Control. The edit control is optional. Both controls are derived from the Module/EditModule class. Those classes are providing information (Reference, Name, etc.) and a configuration infrastructure. Modules are located in the Modules/<ModuleName> directory.
Tabs and Modules have Roles assigned. Users in those roles may view/edit Tabs/Modules. There are four built-in roles:
  • Admin - Administrator Role. May edit/view everything
  • User - Signed in User
  • Everyone - Signed in User or Anonymous User
  • Anonymous - Not signed in User
The Portal definition and Users are stored in a XML File.
Currently there is a "Frame" and a "Table" version (configured in the web.config file). This is how the Portal is rendered: In Frames or in a Table.

Classes

Class NameDescription
Definitions
PortalDefinitionThis is the main Portal Definition class. It contains various helper functions and a list of Tabs.
PortalDefinition.TabThe Tab Definition. A Tab has a Name, Reference, Roles, Sub Tabs and left/middle/right Modules.
PortalDefinition.ModuleA Module has a Name, Reference and Roles.
PortalDefinition.RoleA Role is just a Name and Base Class for View or Edit Roles
PortalDefinition.EditRoleEdit Role.
PortalDefinition.ViewRoleView Role.
UsersUser/Roles Dataset.
ModuleSettingsDefines Module Settings like the Module Control Name.
Controls/Rendering
EditLinkRenders the Edit Link.
ModuleFailedRenders a "Module failed to load".
ModuleHeaderRenders the Module Header.
OverlayMenuRenders a Menu.
OverlayMenuItemRenders a Menu Item.
PortalTabThis is the main Protal Render Control!
TabMenuRenders the Tab Menu.
TabPathRenders the current Tab Path.
TabHttpHandlerThe HttpModule for "translating" URLs.
Helper
HelperCommon Helper Class.
UserManagementUsermanagement Methods.
API
ConfigConfiguration Helpers.
EditModuleBase Class for Module Edit Controls.
ModuleBase Class for Module View Controls.
ASPX-Pages are used as container for Web User Controls. They have hardly program logic.

Storage

Two things must be stored: the Portal Definition and Users/Roles.
The Portal definition is stored with the XML-Serializer.
[XmlRoot("portal"), Serializable]
public class PortalDefinition
{
// Static Serializer

private static XmlSerializer xmlPortalDef =
new XmlSerializer(typeof(PortalDefinition));
...
// Loads the Portal Definition

public static PortalDefinition Load()
{
// Create a Text Reader which reads the file

XmlTextReader xmlReader = new XmlTextReader(
Config.GetPortalDefinitionPhysicalPath());
// Deserialize

PortalDefinition pd = (PortalDefinition)xmlPortalDef.Deserialize(
xmlReader);
// Close the file

xmlReader.Close();

return pd;
}
// Saves the Portal Definition

public void Save()
{
// Create a Text Writer which writes the file

XmlTextWriter xmlWriter = new XmlTextWriter(
Config.GetPortalDefinitionPhysicalPath(), System.Text.Encoding.UTF8);
// Set Formating

xmlWriter.Formatting = Formatting.Indented;
// Serialize

xmlPortalDef.Serialize(xmlWriter, this);
// Close the file

xmlWriter.Close();
}
...
}
Users are stored in a Dataset
public class UserManagement
{
...
// Reads the User Dataset from a file

public static Users GetUsers()
{
Users u = new Users();
u.ReadXml(Config.GetUserListPhysicalPath());
return u;
}

// Writes the User Dataset to a file

public static void SetUsers(Users u)
{
u.WriteXml(Config.GetUserListPhysicalPath());
}
...
}

Authentication

Forms Authentication is used, but I can imagine that Windows Authentication would also work.
First, in the Login Module, your credentials are validated. This is done through a helper method.
Login.ascx
void OnLogin(object sender, EventArgs args)
{
if(Portal.UserManagement.Login(account.Text, password.Text))
{
Response.Redirect(Request.RawUrl);
}
else
{
lError.Text = "Invalid Login";
}
}
UserManagement.cs
public static bool Login(string account, string password)
{
// Load Dataset

Users u = GetUsers();

// Find user

Users.UserRow user = u.User.FindBylogin(account.ToLower());
if(user == null) return false;

// Check password

if(user.password != password) return false;

// Set Authentication Cookie

FormsAuthentication.SetAuthCookie(account, false);
return true;
}
When a Http-Request occurs, Global.Application_AuthenticateRequest is called. There the user roles are set.
protected void Application_AuthenticateRequest(Object sender, EventArgs e)
{
if(Request.IsAuthenticated)
{
// Read users roles

string[] roles = UserManagement.GetRoles(
HttpContext.Current.User.Identity.Name);
// Set a new Principal with the proper roles

HttpContext.Current.User = new GenericPrincipal(
HttpContext.Current.User.Identity, roles);
}
}
UserManagement.cs
public static string[] GetRoles(string account)
{
// Load the User Dataset

Users u = GetUsers();

// Find the current user

Users.UserRow user = u.User.FindBylogin(account.ToLower());
if(user == null) return new string[0];

// Read users roles and add to a string array

Users.UserRoleRow[] roles = user.GetUserRoleRows();
string[] result = new string[roles.Length];
for(int i=0;i<roles.Length;i++)
{
result[i] = roles[i].RoleRow.name;
}

return result;
}

Loading Controls Dynamically

The PortalTab.ascx Web User Control renders the Tabs. The current Tab reference is passed as a URL Parameter. Modules are loaded in the OnInit Event so they can process their OnLoad Events.
public abstract class PortalTab : System.Web.UI.UserControl
{
// Table Cells where the Modules are rendered

protected HtmlTableCell left;
protected HtmlTableCell middle;
protected HtmlTableCell right;

// Renders a Module Column

private void RenderModules(HtmlTableCell td, PortalDefinition.Tab tab,
ArrayList modules)
{
// Hide the cell if there where no Modules

if(modules.Count == 0)
{
td.Visible = false;
return;
}
foreach(PortalDefinition.Module md in modules)
{
// Only if the User has view rights

if(UserManagement.HasViewRights(Page.User, md.roles))
{
md.LoadModuleSettings();

// Initialize the Module

Module m = null;

// Load the Module

if(md.moduleSettings == null)
{
m = (Module)LoadControl(Config.GetModuleVirtualPath(md.type)
+ md.type + ".ascx");
}
else
{
m = (Module)LoadControl(Config.GetModuleVirtualPath(md.type)
+ md.moduleSettings.ctrl);
}
// Initialize the Module

m.InitModule(tab.reference, md.reference,
Config.GetModuleVirtualPath(md.type),
UserManagement.HasEditRights(Page.User, md.roles));

// Each Module can decide if it wants to be rendered.

// The Login Module does so.

if(m.IsVisible())
{
// Add Module Header

ModuleHeader mh = (ModuleHeader)LoadControl("ModuleHeader.ascx");
mh.SetModuleConfig(md);
td.Controls.Add(mh);

// Add Module

HtmlGenericControl div = new HtmlGenericControl("div");
div.Attributes.Add("class", "Module");
div.Controls.Add(m);
td.Controls.Add(div);
}
}
}
}

// Called by the ASP.NET Framework

override protected void OnInit(EventArgs e)
{
PortalDefinition.Tab tab = PortalDefinition.GetCurrentTab();

// Check user rights

if(UserManagement.HasViewRights(Page.User, tab.roles))
{
// Render

RenderModules(left, tab, tab.left);
RenderModules(middle, tab, tab.middle);
RenderModules(right, tab, tab.right);
}

// CODEGEN: This call is required by the ASP.NET Web Form Designer.

InitializeComponent();
base.OnInit(e);
}
...
}

HttpHandler

The HttpHandler is used to "translate" URLs from "http://server/Portal/main.tab.ascx" to"http://server/Portal/RenderTable.aspx?TabRef=main". This is interesting if you want to analyze your Web Server Log Files.
To get this work you must add this to your web.config file
<system.web>
<httpHandlers>
<add verb="*" path="*.tab.aspx" type="Portal.TabHttpHandler, Portal" />
<httpHandlers>
<system.web>
".tab.aspx" is used as a extension, because otherwise you have to reconfigure your IIS.
This HttpModule does nothing else than a simple Server.Transfer
public class TabHttpHandler : IHttpHandler, IRequiresSessionState
{
public void ProcessRequest(HttpContext context)
{
// Parse the URL and extract the Tab Reference

string path = context.Request.Url.AbsolutePath.ToLower();
string tabRef = path.Substring(path.LastIndexOf("/") + 1);
// get "TabRef.tab"

tabRef = tabRef.Substring(0, tabRef.LastIndexOf(".tab.aspx"));
// get "TabRef"


// Save URL Parameter

Hashtable r = new Hashtable();
foreach(string key in context.Request.QueryString.Keys)
{
r[key] = context.Request[key];
}

r["TabRef"] = tabRef;

// Read the configuration to determinate the current main page

string url = Portal.API.Config.GetMainPage();

// Build the URL

bool firstParam = true;
foreach(DictionaryEntry e in r)
{
if(firstParam)
{
url += "?";
firstParam = false;
}
else
{
url += "&";
}
url += e.Key.ToString() + "=" + e.Value.ToString();
}

// Redirect

context.Server.Transfer(url);
}

public bool IsReusable
{
get
{
return true;
}
}
}

Creating a Module

Creating a Module is simple. Just create a directory in the Modules directory and put there the View- and Edit Web User Control. The Controls names must be (or can be reconfigured) <ModuleName>.ascx and Edit<ModuleName>.ascx.

Implementation

Just derive form Portal.API.Module or Portal.API.EditModule and implement "IsVisible" if necessary.
The Module Class provides some properties and methods which describes the Module.

Current Module Settings

NameDescription
IsVisibleCan be overridden. Tells the Portal Framework if the Module should be rendered or not.
TabRefThe current Tab Reference. This is a unique string.
ModuleRefThe current Module Reference. The Module Reference is not necessarily unique. TabRef + ModuleRef is unique.
ModuleVirtualPathThe virtual path to the Module.
ModulePhysicalPathThe physical path to the Module.
BuildURLBuild a URL to the current Page. Use this method to implement Modules that needs URL Parameter.
ModuleHasEditRightsTrue if the current user has edit rights.

Configuration

Each Module has the responsibility to store its configuration and state. The Portal API provides some Helper Methods.
NameDescription
ModuleConfigFilePhysical Path to the configuration file. (<ModulePhysicalPath>\Module_<ModuleRef>.config)
ModuleConfigSchemaFilePhysical Path to the configuration schema file. (<ModulePhysicalPath>\ Module_<ModuleRef>.configModule.xsd)
ReadCommonConfigReads (XML Deserialize) the common configuration file.
ReadConfigReads (XML Deserialize/Dataset) the configuration file.
WriteConfigWrites (XML Serialize/Dataset) the configuration file.
Furthermore each Module can a configure its control files. These settings are stored in the "ModuleSettings.config" file.
<module>
<ctrl>Counter.ascx</ctrl>
<editCtrl>none</editCtrl>
</module>
The "ctrl" Tag defines the View Web User Control. The "editCtrl" Tag can contain "none", which means: there is no Edit Control. E.g. the Login or HitCounter Modules are using this.

Example (Simple Html Module)

This simple Module reads a .htm file and renders it into a DIV Tag.
View Control Html.ascx:
<%@ Control Language="c#" Inherits="Portal.API.Module" %>
<%@ Import namespace="System.IO" %>
<script runat="server">
private string GetPath()
{
return ModulePhysicalPath + ModuleRef + ".htm";
}

void Page_Load(object sender, EventArgs args)
{
// Open file

if(File.Exists(GetPath()))
{
FileStream fs = File.OpenRead(GetPath());
StreamReader sr = new StreamReader(fs);
content.InnerHtml = sr.ReadToEnd();
fs.Close();
}
}

</script>
<div id="content" runat="server">
</div>
Edit Control EditHtml.ascx:
<%@ Control Language="c#" autoeventwireup="true" 
Inherits
="Portal.API.EditModule" %>
<%@ Import namespace="System.IO" %>
<script runat="server">

private string GetPath()
{
return ModulePhysicalPath + ModuleRef + ".htm";
}

void Page_Load(object sender, EventArgs args)
{
if(!IsPostBack)
{
// Open file

if(File.Exists(GetPath()))
{
FileStream fs = File.OpenRead(GetPath());
StreamReader sr = new StreamReader(fs);
txt.Text = sr.ReadToEnd();
fs.Close();
}
}
}

void OnSave(object sender, EventArgs args)
{
FileStream fs = null;
try
{
fs = new FileStream(GetPath(), FileMode.OpenOrCreate,
FileAccess.ReadWrite, FileShare.None);
fs.SetLength(0); // Truncate

StreamWriter sw = new StreamWriter(fs);
sw.Write(txt.Text);
sw.Close();

}
finally
{
if(fs != null)
{
fs.Close();
}
}
RedirectBack();
}

</script>
<asp:TextBox id="txt" Width="100%" Height="300px"
TextMode="MultiLine" Runat="server"></asp:TextBox>
<asp:LinkButton CssClass="LinkButton" runat="server" OnClick="OnSave">
Save & Back</asp:LinkButton>