Blog posts by Martin Helgesen

Blog posts by Martin Helgesen2011-01-16T18:30:46.0000000Zhttps://world.optimizely.com/blogs/Martin-Helgesen/ Optimizely World Chain of data fetchingI’m sure you are familiar with the EPiServer feature that allows a page to fetch data from another page. A webeditor can easily enable this feature in edit mode, and this works fine. But what about a page that fetches data from a page that fetches data from another page? In this case we have a chain of 3 pages in inheritance. What does EPiServer do about this? Let’s try: <ul style="width: 406px; height: 350px"> <li>Page A</li> <ul> <li>Heading – “Base Page”</li> <li>MainBody – “Base Page Body”</li> </ul> <li>Page B</li> <ul> <li>Heading – “Company Page”</li> <li>MainBody – empty</li> <li>Fetches data from Page A</li> </ul> <li>Page C</li> <ul> <li>Heading – “Department Page”</li> <li>MainBody – empty</li> <li>Fetches data from Page B</li> </ul> </ul> When showing Page B the MainBody propertys value will be “Base Page Body”. However, when showing Page C the MainBody property will be empty. Let’s say you want to set up a site for a big company with subcompnaies and departments. 3 chains. And the top company want to distribute pages to the subcompanies with company guidelines that can be overridden. And, likewise, the subcompanies want to distribute those pages to the departments. One way of getting this to work is to have chains of data-fetching. In our example, this means that Page C’s MainBody would not be empty when shown. It would have shown data from Page A. The solution to this is to implement your own GetPropertyHandler. Using reflector, I fetched the code for EPiServer’s default property handler, and modified it:   <pre class="language-csharp"><code>namespace EPiServer.Custom.Handlers { public class PropertyHandlers { public static PropertyData DefaultPropertyHandler(string name, PropertyDataCollection properties) { PropertyData data = properties.Get(name); if (data != null) { if (!data.IsNull || data.IsMetaData) { return data; } } PropertyData data3 = FetchDataFrom(name, properties); if ((data3 != null) && (data3.Value != null)) { return data3; } return (DynamicPropertyCache.DynamicPropertyFinder.FindDynamicProperty(name, properties) ?? data); } public static PropertyData FetchDataFrom(string name, PropertyDataCollection properties) { PropertyData data = properties.Get("PageShortcutType"); if (((data == null) || (data.Value == null)) || (((PageShortcutType)data.Value) != PageShortcutType.FetchData)) { return null; } data = properties.Get("PageShortcutLink"); if (data == null) { return null; } PageReference pageLink = (PageReference)data.Value; if (!PageReference.IsValue(pageLink)) { return null; } string languageBranch = properties.Get("PageLanguageBranch").Value as string; return GetPropertyFromPage(pageLink, languageBranch, name); } private static PropertyData GetPropertyFromPage(PageReference fetchPageLink, string languageBranch, string propertyName) { PageData page; if (string.IsNullOrEmpty(languageBranch)) { page = DataFactory.Instance.GetPage(fetchPageLink); } else { page = DataFactory.Instance.GetPage(fetchPageLink, LanguageSelector.Fallback(languageBranch, true)); } PropertyData data2 = page.Property.Get(propertyName); if (((data2 != null) && !data2.IsLanguageSpecific) && (data2.Value == null)) { return DataFactory.Instance.GetPage(page.PageLink, LanguageSelector.MasterLanguage()).Property.Get(data2.Name); } if (string.Compare(propertyName, "MainBody", StringComparison.OrdinalIgnoreCase) == 0) { var data3 = FetchDataFrom(propertyName, page.Property); if (data3 != null) { return data3; } } return data2; } } }</code></pre> <style type="text/css"><![CDATA[ .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }]]></style> As you can see from the code, this fetch data logic is recursive as long as the property is named “MainBody”. And then, you have hook up this handler in Global.asax Application_Start method: <pre class="language-csharp"><code> protected void Application_Start(Object sender, EventArgs e) { XFormControl.ControlSetup += new EventHandler(XForm_ControlSetup); PropertyDataCollection.GetHandler = EPiServer.Custom.Handlers.PropertyHandlers.DefaultPropertyHandler; }</code></pre> <style type="text/css"><![CDATA[ .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }]]></style> I guess there are other ways of solving chains of inheritance, feedback is very welcome <img style="border-bottom-style: none; border-right-style: none; border-top-style: none; border-left-style: none" class="wlEmoticon wlEmoticon-smile" alt="Smilefjes" src="/link/00043480c63f43ec84a52c87906a433e.png" />2011-01-16T18:30:46.0000000Z

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Access Control with the new Visitor Groups featureJust a quick follow-up from my previous post <a href="http://world.episerver.com/Blogs/Martin-Helgesen/Dates/2010/11/Virtual-Roles-and-access-control-in-EPiServer/">Virtual-Roles-and-access-control-in-EPiServer</a>: In that situation I had to solve a problem for a customer where certain endusers (not authenticated) should have access to more pages than other users. These users could be identified from an IP-range. The solution then was to implement a Virtual Role and every user that matched a specific IP-range gained that role automatically. Then the webeditors could set access rights on pages based on this role. With the new EPiServer CMS 6 R2 feature “Visitor Groups” this could be done in another way. With a little help from Magnus excellent post <a href="http://world.episerver.com/Blogs/Magnus-Paulsson/Dates/2010/12/Building-custom-criteria-for-Visitor-groups-in-CMS-6-R2/">Building-custom-criteria-for-Visitor-groups-in-CMS-6-R2/</a> I created a custom criterion “IPAddress” for the Visitor Groups and then the webeditors can define as many groups they want to based on an IP range match. Her is my criterion: <pre class="language-csharp"><code> [VisitorGroupCriterion( Category = "User Criteria", DisplayName = "IPAddress", Description = "Criterion that matches type and version of the user's browser", LanguagePath = "/shell/cms/visitorgroups/criteria/ipaddresscriterion/ipaddress")] public class IPCriterion : CriterionBase<IPModel> { public override bool IsMatch(System.Security.Principal.IPrincipal principal, HttpContextBase httpContext) { return IsInRange(httpContext.Request.UserHostAddress); } private bool IsInRange(string clientIpAddress) { byte[] clientIP = IPAddress.Parse(clientIpAddress).GetAddressBytes(); byte[] mask = IPAddress.Parse(Model.Mask).GetAddressBytes(); byte[] ip = IPAddress.Parse(Model.Address).GetAddressBytes(); bool isequal = true; for (int i = 0; i < ip.Length; i++) if ((clientIP[i] & mask[i]) != (ip[i] & mask[i])) { isequal = false; break; } return isequal; }</code></pre> <style type="text/css"><![CDATA[ .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }]]></style> And the model looks like: <pre class="language-csharp"><code> public class IPModel : IDynamicData, ICloneable { public EPiServer.Data.Identity Id { get; set; } public object Clone() { var model = (IPModel)base.MemberwiseClone(); model.Id = Identity.NewIdentity(); return model; } [DojoWidget( DefaultValue = "127.0.0.1", LabelTranslationKey = "/shell/cms/visitorgroups/criteria/ipaddresscriterion/ipaddress", AdditionalOptions = "{ selectOnClick: true }"), Required] public string Address { get; set; } [DojoWidget( DefaultValue = "255.255.255.0", LabelTranslationKey = "/shell/cms/visitorgroups/criteria/ipaddresscriterion/mask", AdditionalOptions = "{ selectOnClick: true }"), Required] public string Mask { get; set; } }</code></pre> <style type="text/css"><![CDATA[ .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }]]></style> Now it looks like this in the Admin mode: <a href="/link/ec8ffdaf841b4daea025d7998aa77dbe.png"><img style="background-image: none; border-right-width: 0px; padding-left: 0px; padding-right: 0px; display: inline; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px; padding-top: 0px" title="visitorgroups" border="0" alt="visitorgroups" src="/link/336871f6a0d84b1a9fd9c3cdea69870c.png" width="577" height="238" /></a>2011-01-02T11:04:17.0000000Z

Blog post

Virtual Roles and access control in EPiServerIn some scenarios in EPiServer you may need to create your own logic for accessing specific pages. This can be done in several ways, but one of them is to implement your own Virtual Role. EPiServer default includes a set of virtual roles which are being used frequently. Let’s say you have an open webportal in your company, no need to log in. And one department in the company, located in another part of the world, should see a set of pages (and its children), while the rest of the company should not. This department has specific IP addresses so we can recognize a request from this specific department from the IP address. One solution would be to create a virtual role that compares the request IP to a set of pre-defined IP ranges (e.g from a config file). Let’s call this role “Employee”. you have to register it in web.config like this (added to the bottom after the default roles): <virtualRoles replacePrincipal="true"> <providers> <add name="Administrators" type="EPiServer.Security.WindowsAdministratorsRole, EPiServer" /> <add name="Everyone" type="EPiServer.Security.EveryoneRole, EPiServer" /> <add name="Authenticated" type="EPiServer.Security.AuthenticatedRole, EPiServer" /> <add name="Anonymous" type="EPiServer.Security.AnonymousRole, EPiServer" /> <add name="Creator" type="EPiServer.Security.CreatorRole, EPiServer" /> <add name="Employee" type="YourType, YourAssembly" /> </providers> </virtualRoles> Then you have to create the implementation of the class. Inherit from the EPiServer.Security.VirtualRoleProviderBaseclass. Here is a class that compares the requests IP address: <pre lang="javascript">public class EmployeeRole : EPiServer.Security.VirtualRoleProviderBase { public override bool IsInVirtualRole(IPrincipal principal, object context) { var clientIpAddress = HttpContext.Current.Request.UserHostAddress; var validAddresses = new System.Xml.XmlDocument(); validAddresses.Load(System.Web.HttpContext.Current.Server.MapPath("/ipaddresses.config")); var isequal = validAddresses.SelectNodes("//IPSet/ip").Cast().Any(node =&gt; IsInRange(clientIpAddress, node)); return isequal; }   private static bool IsInRange(string clientIpAddress, XmlNode node) { byte[] clientIP = IPAddress.Parse(clientIpAddress).GetAddressBytes(); byte[] mask = IPAddress.Parse(node.Attributes["mask"].Value).GetAddressBytes(); byte[] ip = IPAddress.Parse(node.Attributes["address"].Value).GetAddressBytes(); bool isequal = true; for (int i = 0; i &lt; ip.Length; i++) if ((clientIP[i] &amp; mask[i]) != ip[i]) { isequal = false; break; } return isequal; } }</pre> There you are finished creating your role! But how do you assign this role read-rights to a specific page and its subpages? Do it in edit mode. But first, you have to create a new group with the same name as the role you just created. EPi will then automatically associate this group with your created Virtual Role. After this, you can just add access rights for the group “Employee” to the pages in EPi you want.2010-11-30T15:38:14.0000000Z

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