ASP.NET

WCF and EPiServer: Using WCF Web Programming Model Services in EPiServer sites on IIS 7

Stephen Horsfield — Thu, 20 Nov 2008 17:10:58 GMT

I've just managed to get the .NET 3.5 style of WCF Web Programming Model services to work inside an EPiServer 5 R2 site on IIS 7 and Windows 2008. I had a few difficulties finding out how to integrate the new model into IIS/ASP.NET and then further problems getting it working in EPiServer. Here, I outline the solution.

Context

I'm currently designing a site that will be using the Akamai Edge Suite of technologies (www.akamai.com) and so I desire that all client access is through the caching layer. Additionally, I'm motivated towards a REST model for web services to support a greater degree of caching.

The new WCF Web Programming Model is ideal for this purpose as I can wrap service parameters directly into the URL and reduce the coding effort considerably. I had been concerned about the integration of services into the same website as EPiServer because of how the URL mapping works in the Web Programming Model.

Solution

The solution is really easy once you realise that the typical EPiServer installation changes the default ASP.NET configuration. Specifically, you may need the following:

Create a new folder to host your services
Create a small web.config in this folder (or use location tags in the main web.config file) and add service handlers
Create a ".svc" file for the service
Create the supporting .NET service code

Create a new folder to host your services

This is necessary to allow a separate application configuration. You can change the main application configuration at your own risk, however :)

For the purposes of this post, I'll use "~/services/".

Create a small web.config for this folder and add service handlers

You'll need to add the following:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <system.webServer>
    <handlers>
      <add name="svc-ISAPI" path="*.svc" verb="*" modules="IsapiModule" 
           scriptProcessor="%SystemRoot%\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll"
           resourceType="Unspecified" 
           preCondition="classicMode,runtimeVersionv2.0,bitness32" />
      <add name="ServiceHost" path="*.svc" verb="*"
           type="System.ServiceModel.Activation.HttpHandler, System.ServiceModel,
                 Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
           resourceType="Unspecified" preCondition="integratedMode" />
    </handlers>
  </system.webServer>
</configuration>

Now I took this from a cleanly created website with no configuration (using the IIS management console) and I recommend that you do the same.

Create a ".svc" file for the service

This file is created in the service folder and forms part of the URL so name it accordingly. I'll just use "service.svc" for illustration:

<%@ ServiceHost Language="C#" Service="Service" CodeBehind="~/App_Code/service.cs"
    Factory="System.ServiceModel.Activation.WebServiceHostFactory" %>

You should name your services more appropriately, of course.

Create the supporting .NET service code

So, you need to create the classes. Here, I'm using a simple file in the App_Code folder, but you might prefer to use a separate code project and assembly. Here's a simple example:

using System.ServiceModel;
using System.ServiceModel.Web;

[ServiceContract]
public interface IService
{
  [OperationContract]
  [WebGet(UriTemplate = "test?s={s}")]
  string test(string s);
}

public class Service : IService
{
  public string test(string s)
  {
    return "test: " + s;
  }
}

So, this is a very basic service with a single HTTP GET method that returns some data dependent on a single query string parameter. A perfect REST example as the result is defined by the input, there is no change of state (so two identical GET requests result in the same value) and so the response is suitable for caching.

Using the service

So now, you can access the service as http://your_episerver_site/services/service.svc/test?s=YourTestString. ASP.NET integration (and IIS) requires the use of a service extension, in this case ".svc", however this article may help you to remove this issue: http://blogs.msdn.com/bags/archive/2008/08/22/rest-in-wcf-part-ix-controlling-the-uri.aspx but don't forget that EPiServer already does some URL rewriting and so you'll have to make sure they don't conflict!

Metadata

Categories: ASP.NET, EPiServer, SOA, WCF, .NET, Windows Server
Keywords: Web Programming Model, Windows Communication Foundation, Service Oriented Architecture, AJAX, JSON
Technorati Tags: software development, Windows Communication Foundation, .NET, JSON, WCF, SOA, service design, Service Oriented Architecture, EPiServer, ASP.NET, AJAX

SubText: Supporting additional feeds (category, month, day)

Stephen Horsfield — Tue, 06 May 2008 12:47:03 GMT

Overview

Some of you might have recognised that we are using a customised version of the SubText blogging engine for these blogs. Recently, I've made some changes to support additional feeds and I thought I'd share them with you.

Goals

We wanted to support context-specific feeds throughout the blog site. Since we host multiple blogs in the same site, this meant that we had the following requirements:

Enable access to the aggregated RSS feed throughout the site
Enable access to the main blog feed in both Atom and Rss formats
Enable access to category, day and month feeds from relevant pages

Solution

To address this issue, I found the following:

The existing Rss.aspx and Atom.aspx pages already supported blog-specific RSS and Atom feeds, but the atom link wasn't being created correctly
The existing MainFeed.aspx page supported an aggregated RSS feed but wasn't available as a link throughout the site
A handler existed to support an RSS category-specific feed, but not for day/month archives

My solution comprised two main parts:

A new ASP.NET user control to implement context-specific feed links on all pages
A new ASP.NET handler to implement a day-specific and month-specific RSS feed

Part 1: Context-specific feed links

The existing pages already linked to feeds, but these weren't correctly configured. Instead of changing them, I replaced them with a single ASP.NET user control to make it easier to manage. This control had the following markup:

<link runat="server" id="HeaderFeedLinks_Atom" type="application/atom+xml" 
    title="Blog (Atom)" rel="alternate" visible="false" />
<link runat="server" id="HeaderFeedLinks_RSS" type="application/rss+xml" 
    title="Blog (Rss)" rel="alternate" visible="false" />
<link runat="server" id="HeaderFeedLinks_Agg" href="/MainFeed.aspx"
    type="application/rss+xml" title="Aggregated Feed (RSS)"
    rel="alternate" />
<link runat="server" id="HeaderFeedLinks_LocalRSS" type="application/rss+xml"
    title="Viewed Content (Rss)" rel="alternate" visible="false" />

As you can see, there isn't much special here except that the links aren't specified in most cases and also that most of the links are not visible by default.

The code-behind for the control determines which links to display and configures them appropriately:

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using Subtext.Web.UI.Pages;
using Subtext.Web.UI.Controls;
using Subtext.Framework;
using System.Text.RegularExpressions;

public partial class HeaderFeedLinks : Subtext.Web.UI.Controls.BaseControl
{

    protected void Page_Load(object sender, EventArgs e)
    {
        string path = Request.Url.AbsolutePath;
        
        /* Looking for different cases as follows
         * 
         * 1. Site root pages - aggregated feed only
         * 2. Blog root pages - complete individual feeds
         * 2. Category pages - category specific feeds
         * 3. Archive summary pages - year, month, day feeds
         * 4. Individual posts - complete individual feeds
         * 
         */

        HeaderFeedLinks_Agg.Attributes["href"] = 
            HttpContext.Current.Request.ApplicationPath + "MainFeed.aspx";
        
        BlogInfo bi = this.CurrentBlog;

        if (bi == null) return; // only show the aggregated feed

        if (bi.RootUrl.AbsolutePath == HttpContext.Current.Request.ApplicationPath)
        {
            return; // only show the aggregated feed
        }
        string baseUrl = bi.RootUrl.AbsolutePath;
        if (!path.StartsWith(baseUrl)) return; // unusual path
        string relPath = path.Substring(baseUrl.Length);
        string feedPath = String.Empty;
        bool hasLocal = false;

        if (bi.FeedBurnerEnabled && (!String.IsNullOrEmpty(bi.FeedBurnerName)))
        {
            HeaderFeedLinks_RSS.Visible = true;
            HeaderFeedLinks_Atom.Visible = true;
            HeaderFeedLinks_RSS.Attributes["href"] = 
              "http://feeds.feedburner.com/" + bi.FeedBurnerName;
            HeaderFeedLinks_Atom.Attributes["href"] = 
          "http://feeds.feedburner.com/" + bi.FeedBurnerName;
        }
        else
        {
            HeaderFeedLinks_RSS.Visible = true;
            HeaderFeedLinks_Atom.Visible = true;
            HeaderFeedLinks_RSS.Attributes["href"] = baseUrl + "rss.aspx";
            HeaderFeedLinks_Atom.Attributes["href"] = baseUrl + "atom.aspx";
        }
        
        if (relPath.Length > 0)
        {
            string ptYear = @"([0-9]{4})";
            string ptMonth = @"([0-9]{2})";
            string ptDay = @"([0-9]{2})";
            string ptFileAndQuery = @"([^?/]+)\.aspx($|\?.*$)";
            string ptCat = @"^category";
            string ptArchive = @"^archive";

            // cases: category, post, day, month, year

            string patCategory = ptCat + "/" + ptFileAndQuery;
            string patYear = ptArchive + "/" + ptFileAndQuery;
            string patMonth = ptArchive + "/" + ptYear + "/" + ptFileAndQuery;
            string patDay = ptArchive + "/" + ptYear + "/" + ptMonth + "/" 
                          + ptFileAndQuery; // -> archive/(1)/(2)/(3)/feed.aspx
            string patPost = ptArchive + "/" + ptYear + "/" + ptMonth + "/" 
                           + ptDay + "/" + ptFileAndQuery;

            Regex reCat = new Regex(patCategory, RegexOptions.IgnoreCase);
            Regex reYear = new Regex(patYear, RegexOptions.IgnoreCase);
            Regex reMonth = new Regex(patMonth, RegexOptions.IgnoreCase);
            Regex reDay = new Regex(patDay, RegexOptions.IgnoreCase);
            Regex rePost = new Regex(patPost, RegexOptions.IgnoreCase);

            if (rePost.IsMatch(relPath))
            {
                feedPath = String.Empty;
            }
            else if (reCat.IsMatch(relPath))
            {
                feedPath = reCat.Replace(relPath, "category/$1.aspx/rss");
                hasLocal = true;
            }
            else if (reYear.IsMatch(relPath)) // not supported by SubText
            {
                feedPath = reYear.Replace(relPath, "archive/$1/");
            }
            else if (reMonth.IsMatch(relPath))
            {
                feedPath = reMonth.Replace(relPath, "archive/$1/$2.aspx/rss");
                hasLocal = true;
            }
            else if (reDay.IsMatch(relPath))
            {
                feedPath = reDay.Replace(relPath, "archive/$1/$2/$3.aspx/rss");
                hasLocal = true;
            }
            else
            {
                feedPath = string.Empty;
            }
        }
        if (hasLocal)
        {
            string absFeedPath = baseUrl + feedPath;

            this.HeaderFeedLinks_LocalRSS.Attributes["href"] = absFeedPath;
            this.HeaderFeedLinks_LocalRSS.Visible = true;
        }
    }
}

This control needs to be placed in the DTP.aspx and Default.aspx pages.

Part 2: Day-specific and month-specific RSS feeds

In order to support this, I needed to create a separate class library that included a handler for this output. Having downloaded the source for SubText, I decided to create a modified copy of the Subtext.Framework.Syndication.RssHandler class. The complete code is listed below:

#region Disclaimer/Info
///////////////////////////////////////////////////////////////////////////////
// Subtext WebLog
// 
// Subtext is an open source weblog system that is a fork of the .TEXT
// weblog system.
//
// For updated news and information please visit http://subtextproject.com/
// Subtext is hosted at SourceForge at http://sourceforge.net/projects/subtext
// The development mailing list is at subtext-devs@lists.sourceforge.net 
//
// This project is licensed under the BSD license.  See the License.txt file 
// for more information.
///////////////////////////////////////////////////////////////////////////////
#endregion

using System;
using System.Collections.Generic;
using Subtext.Framework.Data;
using Subtext.Framework;
using Subtext.Framework.Components;
using Subtext.Framework.Syndication;
using Subtext.Framework.Util;
using System.Text.RegularExpressions;


namespace Subtext.Framework.Syndication
{
    /// <summary>
    /// Class used to handle requests for an RSS feed.
    /// </summary>
    public class RssMonthHandler : 
      Subtext.Framework.Syndication.BaseSyndicationHandler<Entry>
    {
        BaseSyndicationWriter<Entry> writer;

        #region  DayMonth support
        DateTime _MonthDay = DateTime.MinValue; 

        private bool _isMonth; // only set after Month is accessed
        protected DateTime MonthDay
        {
          get
          {
              if (_MonthDay != DateTime.MinValue) return _MonthDay;

              string ptYear = @"([0-9]{4})";
              string ptMonth = @"([0-9]{2})";
              string ptFileAndQuery = @"([^?/]+)\.aspx/rss($|\?.*$)";
              string ptArchive = @"^archive";

              string patMonth = ptArchive + "/" + ptYear + "/" + ptFileAndQuery;
              string patDay = ptArchive + "/" + ptYear + "/" + ptMonth + "/" +
                ptFileAndQuery; 

              Regex reMonth = new Regex(patMonth, RegexOptions.IgnoreCase);
              Regex reDay = new Regex(patDay, RegexOptions.IgnoreCase);

              string blogRoot = this.CurrentBlog.RootUrl.AbsolutePath;
              string reqPath = this.Context.Request.Url.AbsolutePath;
              string relPath = reqPath.Substring(blogRoot.Length);

              if (reDay.IsMatch(relPath))
              {
                Match match = reDay.Match(relPath);
                _isMonth = false;
                _MonthDay = new DateTime(
                    int.Parse(match.Groups[1].Value),
                    int.Parse(match.Groups[2].Value),
                    int.Parse(match.Groups[3].Value));
              }
              else if (reMonth.IsMatch(relPath))
              {
                Match match = reMonth.Match(relPath);
                _isMonth = true;
                _MonthDay = new DateTime(
                    int.Parse(match.Groups[1].Value),
                    int.Parse(match.Groups[2].Value),
                    1);
              }
              else
              {
                _MonthDay = DateTime.Today;
                _isMonth = true; // present the current month's posts
              }
              return _MonthDay;
          }
        }
        #endregion

        /// <summary>
        /// Returns the key used to cache this feed.
        /// </summary>
        /// <param name="dateLastViewedFeedItemPublished">Date last viewed feed
        /// item published.</param>
        /// <returns></returns>
        protected override string CacheKey(DateTime dateLastViewedFeedItemPublished)
        {
            const string key = 
              "RSS;IndividualArchiveFeed;BlogId:{0};LastViewed:{1};" + 
              "Year:{2};Month:{3};Day:{4}";
            DateTime monthday = this.MonthDay;

            return string.Format(key, CurrentBlog.Id, 
                dateLastViewedFeedItemPublished,
                monthday.Year, monthday.Month ,
                _isMonth ? "ALL" : monthday.Day.ToString());
        }

        /// <summary>
        /// Caches the specified RSS feed.
        /// </summary>
        /// <param name="feed">Feed.</param>
        protected override void Cache(CachedFeed feed)
        {
            Context.Cache.Insert(CacheKey(
                this.SyndicationWriter.DateLastViewedFeedItemPublished), 
                feed, null, DateTime.Now.AddSeconds((double)CacheDuration.Medium), 
                TimeSpan.Zero);
        }

        protected DateTime GetLatestPostStamp(IList<Entry> posts)
        {
            DateTime stamp = DateTime.MinValue;
            foreach (Entry e in posts)
            {
                if (e.DateCreated > stamp) stamp = e.DateCreated;
            }
            return stamp;
        }


        /// <summary>
        /// Gets the syndication writer.
        /// </summary>
        /// <returns></returns>
        protected override BaseSyndicationWriter<Entry> SyndicationWriter
        {
            get
            {
                if (writer == null)
                {
                    
                    DateTime monthday = this.MonthDay;
                    IList<Entry> posts = _isMonth ?
                        Entries.GetPostCollectionByMonth(
                            monthday.Month, monthday.Year) :
                        Entries.GetSingleDay(monthday);
                    DateTime stamp = GetLatestPostStamp(posts);

                    writer = new RssWriter(posts, stamp, this.UseDeltaEncoding);
                }
                return writer;
            }
        }

        /// <summary>
        /// Returns true if the feed is the main feed.  
        /// False for category feeds and comment feeds.
        /// </summary>
        protected override bool IsMainfeed
        {
            get { return false; }
        }
    }
}

All that remains is to link the handler into the web.config:

<HttpHandler pattern="(?:/archive/\d{4}/\d{2}.aspx/rss)$" 
  type="Subtext.Framework.Syndication.RssMonthHandler, HandlerDll" 
  handlerType="Direct" />
<HttpHandler pattern="(?:/archive/\d{4}/\d{2}/\d{2}.aspx/rss)$"
  type="Subtext.Framework.Syndication.RssMonthHandler, HandlerDll" 
  handlerType="Direct" />

Note that these handlers go into the SubText configuration, not the standard ASP.NET handler configuration.

Versions

SubText 1.9.4.78

Metadata

Categories: SubText, blogging, Software Development, ASP.NET, .NET
Additional keywords: SubText API, RSS, Atom
Technorati Tags: ASP.NET, .NET, software development, SubText, SubText API, blogging

Visual Studio: Viewing the .NET framework source code in VS 2008

Stephen Horsfield — Tue, 29 Apr 2008 08:23:19 GMT

Overview

Microsoft have released significant parts of the .NET framework source code for developers using Visual Studio 2008. In case you've not been following the releases, this blog post includes links to configuration and hotfix resources.

Hotfix

Before you attempt to configure the source code, make sure you have the following patch installed:

https://connect.microsoft.com/VisualStudio/Downloads/DownloadDetails.aspx?DownloadID=10443&wa=wsignin1.0

Configuration

I'll not attempt to reproduce perfectly good instructions, so here's a link:

Shawn Burke's Blog: Configuring Visual Studio to Debug .NET Framework Source Code

References

Also referenced:

ScottGu's Blog: .NET Framework Library Source Code now available

Versions

.NET Framework 2.0 and later
Visual Studio 2008 (excluding Express editions)

Metadata

Categories: .NET, Software Development, Visual Studio
Additional keywords: source code
Technorati Tags: .NET, ASP.NET, software development, source code, debugging, Visual Studio

ASP.NET: Integrating Windows Workflow Foundation and marshalling controls

Stephen Horsfield — Fri, 18 Apr 2008 15:19:54 GMT

Overview

I've been playing around a bit with the idea of integrating Windows Workflow Foundation into custom web server controls. I've had some success but also hit something of a wall. If you have any experience with any of these issues, I'd love to hear from you.

Context

I've started with the following hypothesis:

In my experience, developers often make mistakes developing custom controls therefore it is beneficial for controls to be modelled rather than 'coded' and Windows Workflow Foundation is a perfect tool for the job.

In practice

Using a workflow to take the place of aspects of the code is straightforward. I started by providing multiple workflows, each run synchronously to handle a distinct control event. This worked well, but suffered in that each workflow was separated and the code ran synchronously. I desired a better solution.

Next, I updated the code to use the default scheduling service, redeveloped the server control to use a single workflow and created a communication service to handle event passing to the workflow. I also added a HandleExternalEvent activity to the workflow to catch the event.

All looked good, until I threw the event. The event attempted to pass the web server control to the workflow but the control was not marked as Serializable and was also not derived from MarshallByRefObject. This meant that the event could not be raised and ultimately killed this solution.

I'm a bit surprised that you can't marshall web controls across process boundaries. This has implications for interactions with any separated service, not just WWF.

Has anyone else had this issue? Any solutions? It is not practical to create a custom marshalling object for every web control type.

Still, it was good experience to use WWF and a successful attempt at integrating WWF activities into a control's life-cycle.

Versions

.NET Framework 3.5

Metadata

Categories: Windows Workflow Foundation, Software Development, ASP.NET
Additional keywords: ExternalDataEventArgs, ExternalDataExchangeService, DefaultWorkflowSchedulerService, ManualWorkflowSchedulerService
Technorati Tags: .NET, ASP.NET, software development, Windows Workflow Foundation, WF, marshalling

EPiServer: Handling unpublished pages

Stephen Horsfield — Tue, 01 Apr 2008 10:45:55 GMT

Overview

I've recently hit an issue where some custom controls have been generating exceptions when unpublished pages exist in an EPiServer site. In these cases, the relevant (required) properties have null values.

Context

Rather than using the standard EPiServer property controls, these pages use ASP.NET data-binding and custom controls that access the required properties of EPiServer PageData objects. They are being viewed in the editing interface by a logged-in user with full permissions. The PageData object is sourced using a FindPagesWithCriteria operation.

Problem

Any of the custom page properties accessed using PageData["PropertyName"] (in C#) return null preventing the display of any useful information and causing exceptions in various cases, such as in sorting operations and date formatting.

Cause

EPiServer does not automatically load the properties for unpublished pages. You have to manually instruct EPiServer to load them.

Solution

Check to see if the page is unpublished and (optionally) whether the user has appropriate access rights. If appropriate, load the full version of the unpublished page and possibly store it in a PageDataCollection:

   1: public static PageDataCollection LoadUnpublishedAsNecessary(PageDataCollection pdc, 
                                                                  bool clearSource)

   2: {

   3:     PageDataCollection pdc2 = new PageDataCollection();

4:

   5:     foreach (PageData p in pdc)

   6:     {

   7:         if (p.PendingPublish)

   8:         {

   9:             AccessLevel l = p.QueryAccess();

  10:             if (((l & AccessLevel.Edit) == AccessLevel.Edit) ||

  11:                  ((l & AccessLevel.Publish) == AccessLevel.Publish))

  12:             {

13:

  14:                 PageReference r = new PageReference(p.PageLink.ID, true);

  15:                 pdc2.Add(EPiServer.Global.EPDataFactory.GetPage(r));

  16:                 continue;

  17:             }

  18:         }

  19:         pdc2.Add(p);

  20:     }

  21:     if (clearSource) pdc.Clear();

22:

  23:     return pdc2;

  24: }

References

http://www.episerver.com/sv/EPiServer_Knowledge_Center/Developer-Forum2/EPiServer-Developer-Forums-/1805/15069/

Versions

EPiServer 5, EPiServer 4.6

Metadata

Categories: .NET, ASP.NET, EPiServer, Software Development
Additional keywords: FindPagesWithCriteria, saved pages, unpublished, property values null, missing properties
Technorati Tags: .NET, ASP.NET, EPiServer, software development, data binding, page publishing

ASP.NET: Managing Browser History with AJAX and UpdatePanels

Stephen Horsfield — Fri, 25 Jan 2008 07:23:17 GMT

Overview

When you are using the (very helpful) UpdatePanel, the browser doesn't keep track of the asynchronous postbacks. This means that when the user clicks the back button in the browser, they go to the navigation prior to the last full postback.

How can you resolve this?

Solution

You can solve this by programming the browser, but it is even easier with two alternative server control solutions:

ASP.NET Futures: the History server control and the Sys.Application client object. See ASP.NET Futures (July 2007): Managing Browser History and Back Button Support in ASP.NET AJAX
Nikhil Kothari's Weblog : UpdateControls: UpdateHistory and AnimatedUpdatePanel

Versions

Microsoft .NET Framework 2.0
ASP.NET AJAX 1.0
ASP.NET Futures July 2007

Metadata

Categories: Software development, ASP.NET, .NET, AJAX
Additional keywords: browser support, back button, history, UpdateHistory, History control, Sys.Application
Technorati Tags: software development, ASP.NET, AJAX, UpdatePanel, UpdateHistory

EPiServer: FindPagesWithCriteria, Multiple Criteria and Boolean Property Tests

Stephen Horsfield — Fri, 18 Jan 2008 15:53:28 GMT

Overview

This should be easy, but easy it is not. I'm using an EPiServer 4.6 site for this one, so things might've improved in more recent versions, but this caused me a lot of trial and error. I hope this post saves you the hassle.

Context

I've got a Selected/Unselected property set on a Page Type, and I want to search for pages with this property checked. I also want to take account of publishing dates and I've got another date property to check too.

The EPiServer Selected/Unselected property type returns True when selected and Null when it is not. This causes some problems because boolean logic is more complicated when Null values are involved. This is because Null represents "I don't know". If you ask, "Is A equal to B?" and A or B is Null, then the answer is Null... always!

The other problem is that I can only do certain expressions in the query. I can say that some criteria are optional (union set) and some properties are required (intersection set). I cannot reduce or expand a single clause and this limits what is allowed.

My solution

I need to find pages with a date property less than the current date. I'll call this property RequiredBefore
I need to find pages with a boolean property that is set. I'll call this property Flag
I need to find pages that are currently published and accessible to the current user

Here's my code:

PageDataCollection col = new PageDataCollection(); PropertyCriteriaCollection propcol = new PropertyCriteriaCollection(); PropertyCriteria criteria = new PropertyCriteria(); criteria.Type = PropertyDataType.Date; criteria.Name = "RequiredBefore"; criteria.Value = DateTime.Now.ToString(); criteria.Condition = EPiServer.Filters.CompareCondition.GreaterThan; criteria.Required = true; propcol.Add(criteria); criteria = new PropertyCriteria(); criteria.Type = PropertyDataType.Boolean; criteria.Name = "VisibleInSummary"; criteria.IsNull = false; criteria.Value = true.ToString(); criteria.Condition = EPiServer.Filters.CompareCondition.Equal; criteria.Required = true; propcol.Add(criteria); PageDataCollection tempcol = new PageDataCollection(); tempcol = Global.EPDataFactory.FindPagesWithCriteria(CurrentPageLink, propcol, EPiServer.Security.AccessLevel.Read); // Check pages are published foreach (PageData p in tempcol) { if (p.Status == VersionStatus.Published) col.Add(p); } tempcol.Clear();

I'm checking for publishing dates after retrieving the pages which is inefficient. I'm doing this because it is otherwise difficult to handle for the possibility of publishing dates being null, and this way I let EPiServer decide how to check for whether a page is considered published.

Versions

EPiServer 4

Metadata

Categories: Software development, EPiServer, ASP.NET
Additional keywords: EPDataFactory, FindPagesWithCriteria, Search, multiple criteria, Publishing dates, flags, boolean, selected/unselected, PropertyCriteria.IsNull, PropertyCriteria.Required, EPiServer FindPagesWithCriteria, FindPagesWithCriteria EPiServer
Technorati Tags: software development, .NET, ASP.NET, EPiServer, FindPagesWithCriteria, search

EPiServer: PropertyCriteria — GreaterThan Value or Value GreaterThan?

Stephen Horsfield — Fri, 18 Jan 2008 14:15:28 GMT

Overview

Using EPiServer, you may use the FindPagesWithCriteria method to retrieve a list of pages based on certain properties, but the helpfully enumerated conditions may be confusing. After all, with a binary inequality operator it is quite important to know the order of the expressions...

Context

You use PropertyCriteria objects to set the criteria for a search and you can use the Condition property to determine the operator. Suppose you selected the GreaterThan operator:

IF --PROPERTY-- > --VALUE-- THEN

But is it actually:

IF --VALUE-- > --PROPERTY-- THEN

The two operations give entirely different answers, and they are not even inverse. The inverse operator to > (greater-than) is <= (less-than-or-equal).

The answer

A search through the EPiServer documentation reveals that the answer is that EPiServer will use:

IF --PROPERTY-- --CONDITION-- --VALUE-- THEN

Versions

EPiServer 5
EPiServer 4

Metadata

Categories: Software development, EPiServer, ASP.NET
Additional keywords: EPDataFactory, FindPagesWithCriteria, Search, Publishing dates, binary operator, inequality, Greater than, Less than, CompareCondition, PageStartPublish, PageStopPublish
Technorati Tags: software development, .NET, ASP.NET, EPiServer, FindPagesWithCriteria, search

EPiServer: Problems importing data — POST fails

Stephen Horsfield — Fri, 18 Jan 2008 10:47:51 GMT

Overview

I've been importing a live EPiServer site into a development environment for further work. Normally, this works without problem, but this time I've been getting a POST error, but nothing informative. What's happening?

Solution

A quick look at the event logs on the IIS server quickly identifies the problem: the file exceeds the upload limit. Of course this is less likely to happen in a normal development run, but once there is a fair amount of data it fails. If I hadn't spotted the error in the event log, I might have been stuck for some time.

The default ASP.NET upload limit is 4 MB, so if you need more you will have to change the web.config settings. The element you have to change is the maxRequestLength attribute on the <system.web><httpRuntime> element. The size is specified in KB, so for a 32 MB limit, use the following:

<system.web> <httpruntime maxrequestlength="32768" /> </system.web>

References

<httpRuntime> Element (Microsoft MSDN)

Versions

Windows Server 2003
Windows XP
Microsoft .NET Framework 2.0

Metadata

Categories: Software Development, ASP.NET, IIS, EPiServer
Additional keywords: import, POST, error, upload limit
Technorati Tags: software development, IT Management, .NET, ASP.NET, EPiServer, import, problem

ASP.NET: Providing browser specific alternatives in ASP.NET

Stephen Horsfield — Thu, 03 Jan 2008 16:21:50 GMT

Overview

Suppose that you have found the perfect control that works with almost all the browsers you need to support, but suppose it has breaking functionality for a particular browser. How can you solve this problem?

One Solution

Sometimes the easiest solution may be a browser specific adapter. The adapter can remove the original control and replace it with one that is only targeted at a single browser (or a subset). Then, when the preferred control is fixed, it can be used directly without changing the application code.

This solution has at least two components:

A change to a browser file in the App_Browsers folder

A control adapter that implements the required functionality. Optionally using an alternative control.

(Optional) an alternative control

Changing the App_Browsers file

In the appropriate browser file, add an adapter entry:
<controlAdapters>
    <adapter controltype="YourNamespace.YourOriginalControl"
             adaptertype="YourNamespace.YourControlAdapter" />
</controlAdapters>
The Control Adapter

The Control Adapter is provided by a class derived from System.Web.UI.Adapters.ControlAdapter. The adapter can provide event handlers for standard events, but typically the OnLoad and Render methods are overidden.

The OnLoad method calls base.OnLoad and might register some client script using the Page.ClientScript.RegisterClientScriptBlock method. It might also enable, disable, add or remove other controls on the page. The OnLoad method may also change the properties of the original control, perhaps adding additional client-side events.

The Render method calls base.Render to render the original control's content. However, it might wrap this in other HTML output that the client script uses to control display or handle additional events.

You use the this.Control property to access the adapted control.

Comments

At the time of writing, the ASP.NET AJAX toolkit's HoverMenuExtender control doesn't work perfectly in Internet Explorer 6. This method was used to remove the HoverMenuExtender from IE6 output and to replace it with custom HTML, JavaScript and event handling. The adapter was applied to the display control, not to the HoverMenuExtender itself.

Versions

Microsoft .NET Framework 3.0
ASP.NET AJAX Toolkit 1.0.10920.23306