Sitecore 9: ContentSearch Solr query quirks with spaces and wildcards

Sitecore provides a Linq powered IQueryable mechanism with which you can build powerful search queries. Your query will be translated into a native query for your underlying search engine (eg. Solr). There are some odd quirks (bugs?) with this translation in Sitecore 9.0 and 9.0.1 when your search term includes a space. Let’s take a look.

In the below examples, context is an instance of IProviderSearchContext, which you’d typically wire up with dependency injection. In each case, we’re looking to query something from the index based the item’s path in the Sitecore tree.

Querying on exact matches:

context.GetQueryable().Where(x => x.Path == "Hello");
 Translates to: {_fullpath:(Hello)}

Ok! This makes sense.

context.GetQueryable().Where(x => x.Path == "Hello World");
 Translates to: {_fullpath:("Hello World")}

Notice that if your query term has a space, we need to wrap the term in quotes.

context.GetQueryable().Where(x => x.Path == "\\Hello");
 Translates to: {_fullpath:(\\Hello)}

Backslash? No problem.

context.GetQueryable().Where(x => x.Path == "/Hello");
 Translates to: {_fullpath:(\/Hello)}

Forwardslash? We need to escape that with a ‘\’

context.GetQueryable().Where(x => x.Path == "\\Hello World");
 Translates to: {_fullpath:("\\Hello World")}

Backslash with space? No problem, just add the quotes.

context.GetQueryable().Where(x => x.Path == "/Hello World");
 Translates to: {_fullpath:("\/Hello World")}

As above, we’re all good, the forwardslash is just escaped.

Querying on partial matches – where things get interesting:

context.GetQueryable().Where(x => x.Path.Contains("Hello"));
 Translates to: {_fullpath:(*Hello*)}

All good. Here, we wrap our search term in a wildcard, *

context.GetQueryable().Where(x => x.Path.Contains("Hello World"));
 Translates to: {_fullpath:("\*Hello\\ World\*")}

Uh oh! Something weird has happened. The quotes and wildcard seem to have got mixed up, and we’ve ended up with something which won’t return the results we want. Having read more about wildcard / space combinations here , we probably want to end up with something simpler, like {_fullpath:(*Hello\ World*)}

context.GetQueryable().Where(x => x.Path.Contains("\\Hello"));
 Translates to: {_fullpath:(*\\Hello*)}

No problem with this partial match, as we don’t have a space to deal with.

context.GetQueryable().Where(x => x.Path.Contains("/Hello"));
 Translates to: {_fullpath:(*\/Hello*)}

Again, fine.

context.GetQueryable().Where(x => x.Path.Contains("\\Hello World"));
 Translates to: {_fullpath:("\*\\Hello\\ World\*")}

The space completely breaks everything here

context.GetQueryable().Where(x => x.Path.Contains("/Hello World"));
 Translates to: {_fullpath:("\*\/Hello\\ World\*")}

and here..


I raised this with Sitecore and it has been raised as a bug. In the meantime – if you can get away with using StartsWith rather than Contains, you’ll find this works OK:

context.GetQueryable().Where(x => x.Path.StartsWith("Hello World"));
 Translates to: {_fullpath:(Hello\ World*)}

Which is just about perfect.

Sitecore 9 : The partial view ‘/sitecore/shell/client/Speak/Layouts/Layouts/Speak-Layout.cshtml’ was not found or no view engine supports the searched locations. The following locations were searched: /sitecore/shell/client/Speak/Layouts/Layouts/Speak-Layout.cshtml

When logging into Sitecore 9 and trying to access the Launchpad (/sitecore/shell/sitecore/client/applications/launchpad) – you may get the following error:

The partial view '/sitecore/shell/client/Speak/Layouts/Layouts/Speak-Layout.cshtml' was not found or no view engine supports the searched locations. The following locations were searched:

This is actually an easy one – make sure you have configured your site to either ContentManagement or Standalone mode. In your Web.config:

<add key="role:define" value="ContentManagement" />


In my case – for testing, I had swapped to ContentDelivery mode and forgotten to change back.

Sitecore Solr Error: Processing Field Name. Resolving Multiple Field found on Solr Field Map. No matching template field on index field name, return type ‘String’ and field type ”

After an upgrade to Sitecore 9, our Sitecore search logs were filled with thousands of warnings, like the below:

WARN Processing Field Name : Overview Text. Resolving Multiple Field found on Solr Field Map. No matching template field on index field name 'overview_text', return type 'String' and field type ''

What’s the fix?

You need to add field mappings for each of the fields in your Solr index. In our case, we had no mapping for ‘overview_text’, so Sitecore / Solr didn’t know how to treat the field. Add a config patch and specify a returnType for the fields you see as warnings in the log:

<configuration xmlns:patch="" xmlns:role="" xmlns:search="">
            <fieldNames hint="raw:AddFieldByFieldName">
              <field fieldName="overview_text" returnType="text" />

** UPDATE 25/01/2018 **

While the above is suitable for adding a few fields, having hundreds or thousands of fields in your Solr index will lead to having to maintain lots of the above configuration entries. I raised a ticket with Sitecore, and was told “We registered this behavior as a bug with the reference #​195567”. Sitecore’s suggested workaround is to add a log4Net filter which will stop the problematic entries from reaching the log. For example:

<!-- Filter out Solr log warnings-->
      <appender name="SearchLogFileAppender">
        <filter type="log4net.Filter.StringMatchFilter">
          <regexToMatch  value="Resolving Multiple Field found on Solr Field Map. No matching solr search field configuration on index field name|Search field name in Solr with Template Resolver is returning no entry|Resolving Multiple Field found on Solr Field Map. No matching template field on index field name|Solr with Template Resolver is returning multiple entry|is being skipped. Reason: No Field Type Name" />
          <acceptOnMatch value="false" />

Hopefully a proper fix or configuration guidance will be released at some point.

Sitecore Solr setup: Document is missing mandatory uniqueKey field: id

While reconfiguring Sitecore (8.2u5) to use Solr (6.6.1) instead of Lucene, I came across the following error:

Document is missing mandatory uniqueKey field: id

In full:

Job started: Index_Update_IndexName=sitecore_master_index|#Exception: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> SolrNet.Exceptions.SolrConnectionException: <?xml version="1.0" encoding="UTF-8"?>
<lst name="responseHeader"><int name="status">400</int><int name="QTime">1</int></lst><lst name="error"><lst name="metadata"><str name="error-class">org.apache.solr.common.SolrException</str><str name="root-error-class">org.apache.solr.common.SolrException</str></lst><str name="msg">Document is missing mandatory uniqueKey field: id</str><int name="code">400</int></lst>
 ---> System.Net.WebException: The remote server returned an error: (400) Bad Request.
 at System.Net.HttpWebRequest.GetResponse()
 at HttpWebAdapters.Adapters.HttpWebRequestAdapter.GetResponse()
 at SolrNet.Impl.SolrConnection.GetResponse(IHttpWebRequest request)
 at SolrNet.Impl.SolrConnection.PostStream(String relativeUrl, String contentType, Stream content, IEnumerable`1 parameters)
 --- End of inner exception stack trace ---
 at SolrNet.Impl.SolrConnection.PostStream(String relativeUrl, String contentType, Stream content, IEnumerable`1 parameters)
 at SolrNet.Impl.SolrConnection.Post(String relativeUrl, String s)

Here’s what to check.

  • Does your Solr core index config directory have a file called managed-schema? If so, delete this file and reload the core. Solr will be ignoring any changes you’re making to schema.xml and using managed-schema instead. Deleting this file and reloading the core will pick up your latest version of schema.xml


Delete this file



Reload the core



Rebuild the index in Sitecore and the error should be gone. 


Digging into Unicorn configs in Sitecore Habitat

Sitecore Habitat ships with Unicorn as the serialization utility of choice. Unicorn works in the background during the development of a Sitecore implementation and writes out a YAML copy of templates, renderings and other Sitecore items to disk.
You can then add these YAML (.yml) files to your version control repository, merge changes with other developers and ensure they are picked up / deployed to target environments as part of your continuous integration (CI) pipeline.

In Habitat, we bundle a Unicorn-specific configuration file with each module – in line with the Helix principle that any assets relating to a module should be bundled and deployed with that module.

If we had a feature module called ‘Car’, we’d create a config patch in App_Config/Include/Feature called Feature.Car.Serialization.Config

<configuration xmlns:patch="">
    <configuration name="Feature.Car" description="Feature Car" dependencies="Foundation.*" extends="Helix.Feature">
      <include domain="modules" pattern="^Feature Car .*$" />

The key line setting up this configuration file is:

<configuration name="Feature.Car" description="Feature Car" dependencies="Foundation.*" extends="Helix.Feature">

Aside from the obvious name and description, dependencies tells Unicorn to run other configurations before this one (in our case, run any other configuration named Foundation.* first. Extends allows us to inherit from a parent config, Helix.Feature. This is a great feature which removes unnecessary code duplication in Helix solutions (which can have hundreds of modules!)

With this simple config (which extends the Helix.Feature abstract configuration), Unicorn will sync any Sitecore definition items under any folder called /Feature/Car in Sitecore. Happily, the Helix.Feature abstract config will ensure that Unicorn puts its .yml files alongside the rest of your source code for the Car module. We can track down the configuration line which determines the serialization location in Unicorn.Helix.config:

<configuration name="Helix.Feature" abstract="true" extends="Helix.Base">
   <include name="Templates" database="master" path="/sitecore/templates/$(layer)/$(module)" />
   <include name="Renderings" database="master" path="/sitecore/layout/renderings/$(layer)/$(module)" />
   <include name="Media" database="master" path="/sitecore/media library/$(layer)/$(module)" />


Read more about Unicorn configuration at Kam’s blog.

Elasticon London 2017 (for a Sitecore developer)

Even though Elasticsearch is built on the same foundations (Apache Lucene) as Solr, we in the Sitecore community don’t see a lot of cases where Solr or Coveo have been replaced by Elasticsearch as the main search component.

Today I’ve been at Elasticon London 2017 and have been soaking up new product releases by Elastic. Here’s some notes I scribbled and points which would be interesting to the Sitecore world.

Elasticsearch 6.0

  • Elasticsearch 6.0 is the next major release – but no firm release date has been set just yet. The official answer right now is “coming soon”.
  • Elastic have recognised how painful the upgrade process is – particularly between 2.x and 5.x. When performing the upgrade, you must re-index all of your data to make it 5.x compatible – a huge job on large clusters!
  • While the 2.x to 5.x upgrade path isn’t going to get much easier, Elastic are making sure that the 5.x to 6.x upgrade path doesn’t require you to re-index all data, or take nodes offline.
  • The .NET client creates REST requests with a JSON payload which proxies requests and responses between your code and the Elasticsearch cluster. This is the client model they’re sticking with, and are actually rewriting the native Java client (which currently doesn’t generate REST requests) to be more in line with the .NET client.
  • When it comes to swapping out Solr and Coveo for Elasticsearch, I think this would be a very individual decision based on the needs of your project.




Anomaly Detection

  • You can now create and set off unsupervised machine learning jobs to continually parse any data and highlight anomalies.
  • The engineer I spoke to said usually “around three weeks” of learning will be enough to begin pulling out anomalies.
  • This could have applications ranging from security (detecting usual IP or DNS activity), to marketing: spotting if a ‘suspicious’ user journey is taking place (whatever this may be!) or perhaps highlighting if a user is stuck or lost.
  • The Elastic stack uses Beats – agents which can monitor a set of files, database, or network packets and streams the data into an Elasticsearch instance / cluster.




  • Elastic founder and CEO Shay Banon announced during his keynote that Elastic have acquired Opbeat, a Copenhagen based company whose product adds monitoring and profiling to JavaScript applications (think Node.js, React and Angular).
  • While this might have limited applicability for a lot of Sitecore solutions (where React and Angular might not be the norm), the interesting thing here will be to wait and see how Elastic fit Opbeat into their stack. My guess would be that they’ll extend the product and make it a more general-purpose monitoring and profiling tool.



Machine Learning

  • Elastic’s Steve Dodson (who heads up the Machine Learning product) showed us the current offering, which again is centred around anomaly detection.
  • Most of Elastic’s demo use-cases for anomaly detection are for ops-level indicators like 404’s, 500s, response time, DDOS detection, and so on. Machine Learning kicks in to ignore ‘regular’ surges such as an increase in page response time during weekly batch jobs – but still alerting if the surge is stronger than usual.
  • With some fiddling, you could set up an anomaly detection profiler which tolerates a certain amount of server errors after a code release (and assumes you’ll fix them), but alerts you if it looks like you’ve broken something really big.
  • There was a preview of forecasting, a feature of the upcoming Elasticsearch 6.0. Forecasting does exactly as you’d expect – look at historical data and predict statistics for a future window.



Elasticsearch SQL

Being an ex-database nerd, I loved this session. I’m not sure how the wider search community are going to feel about writing SQL again, but here’s what Elastic have in development:

  • A SQL-like DSL which is 50% ANSI SQL and 50% Elasticsearch-specific syntax additions.
  • You can run queries like SHOW TABLES to list all indexes, DESCRIBE my_index to show fields (columns) and datatypes. You can run search queries like this:
SELECT * FROM my_index WHERE QUERY('+chris perks')
  • All SQL queries translate into the same old Elasticsearch QueryDSL
  • Other constructs they’re including are GROUP BY, HAVING, even JOINs are in there – all translating to their equivalent Elasticsearch QueryDSL commands.
  • You can even wrap SQL in JSON and use it via a REST call *confused face emoji*
  • This is still heavily in development and won’t be released for a while.



There’s plenty of overlap with what the Elastic stack offers, and what you’ll already have set up with Sitecore, Solr, and xDB. There’ll be a fair amount of plumbing work to get Elasticsearch set up properly with Sitecore, whereas you get this out of the box for Solr and/or Coveo.

As Elastic expand, they’re adding many new tools and capabilities to their stack, so it’s definitely not correct to see Elasticsearch as a like-for-like replacement for Solr or Coveo or parts of xDB.

I can see use cases for engaging Elasticsearch alongside your current setup, if you either need a particular Elastic capability which Sitecore / Solr doesn’t give you (such as Machine Learning, or streaming data). Or, you have more faith in the scaling capability of Elasticsearch than you do Sitecore and Solr.


Visualising Sitecore Analyzers

When Sitecore indexes your content, Lucene analyzers work to break down your text into a series of individual tokens. For instance, a simple analyzer might convert input text to lowercase, split into separate words, and remove punctuation:

  • input: Hi there! My name is Chris.
  • output tokens: “hi”, “there”, “my”, “name”, “is”, “chris”

While this happens behind the scenes, and is usually not of too much interest outside of diagnostics or curiosity, there’s a way we can view the output of the analyzers bundled with Sitecore.

Let’s get some input text to analyze, in both English and French:

var text = "Did the Quick Brown Fox jump over the Lazy Dog?";
var text_fr = "Le Fox brune rapide a-t-il sauté sur le chien paresseux?";

Next, let’s write a generic method which takes some text and a Lucene analyzer, and runs the text through the analyzer:

private static void displayTokens(Analyzer analyzer, string text)
    var stream = analyzer.TokenStream("content", new StringReader(text));
    var term = stream.AddAttribute();
    while (stream.IncrementToken())
      Console.Write("'" + term.Term + "', ");

Now, let’s try this out on some Sitecore analyzers!

  • CaseSensitiveStandardAnalyzer retains case, but removes punctuation and stop words (common words which offer no real value when searching)
displayTokens(new CaseSensitiveStandardAnalyzer(Lucene.Net.Util.Version.LUCENE_30), text);
> 'Did', 'Quick', 'Brown', 'Fox', 'jump', 'over', 'Lazy', 'Dog'
  • LowerCaseKeywordAnalyzer convers the input to lowercase, but retains the punctuation and doesn’t split the input into separate words.
displayTokens(new LowerCaseKeywordAnalyzer(), text);
> 'did the quick brown fox jump over the lazy dog?
  • NGramAnalyzer breaks text up into trigrams which are useful for autocomplete. See more here.
displayTokens(new NGramAnalyzer(), text);
> 'did_the_quick', 'the_quick_brown', 'quick_brown_fox', 'brown_fox_jump', 'fox_jump_over', 'jump_over_the', 'over_the_lazy', 'the_lazy_dog
  • StandardAnalyzerWithStemming introduces stemming, which finds a common root for similar words (lazy, lazily, laze -> lazi)
displayTokens(new StandardAnalyzerWithStemming(Lucene.Net.Util.Version.LUCENE_30), text);
> 'Did', 'the', 'Quick', 'Brown', 'Fox', 'jump', 'over', 'the', 'Lazi', 'Dog'
displayTokens(new SynonymAnalyzer(new XmlSynonymEngine("synonyms.xml")), text);
> 'did', 'quick', 'fast', 'rapid', 'brown', 'fox', 'jump', 'over', 'lazy', 'dog
  • Lastly, we try a FrenchAnalyzer. Stop words are language specific, and so the community often contributes analyzers which will remove stop words in languages other than English. In the example below, we remove common French words.
displayTokens(new FrenchAnalyzer(Lucene.Net.Util.Version.LUCENE_30), text_fr);
> 'le', 'fox', 'brun', 'rapid', 't', 'saut', 'chien', 'pares'

The full code is here: (

Explaining Lucene explain

Each time you perform a search using Lucene, a score is applied to the results returned by your query.

| #   | Score | Tags                 |
| 343 | 2.319 | Movies, Action       |
| 201 | 2.011 | Music, Classical     |
| 454 | 1.424 | Movies, Kids         |
| 012 | 0.003 | Music, Kids          |

In our index, # is the unique document number, score is the the closeness of each hit to our query, and tags is a text field belonging to a document.

There are many methods Lucene can use to calculate scoring. By default, we use the DefaultSimilarity implementation of the Similarity abstract class. This class implements the commonly referenced TfIdf scoring formula:


If you’re new to Lucene (or even if you’re not!) this formula can be a bit to get your head around. To get inside the formula for a given search result, Lucene provides an explanation feature, which we can call from code (c# example in Lucene.Net):

public List GetExplainerByRawQuery(string rawQuery, int doc = 0)
    using (var searcher = new IndexSearcher(_directory, false))
        // Create a parser, and parse a plain-text query which searches for items tagged with 'movies' or 'kids' (or hopefully, both)
        var parser = new QueryParser(Lucene.Net.Util.Version.LUCENE_30, "id", analyzer);
        var query = parser.Parse("tags:(movies OR kids)");

        // Get references to the top 25 results
        var hits = searcher.Search(query, 25).ScoreDocs;

        // For each hit, get the accompanying explanation plan. We now have a List
        var explains = hits.Select((x, i) => searcher.Explain(query, i)).ToList();

        //Clean up and return
        return explains;

Calling searcher.Explain(query, match.doc) gives us a text output explanation of how the matched document scores against the query:

query: tags:movies|kids
| #   | Score  | Tags                              |
| 127 | 2.4824 | Movies, Kids, Animation, Movies   |
2.4824  sum of:
  1.4570  weight(tags:movies in 127) [DefaultSimilarity], result of:
    1.4570  score(doc=127,freq=2.0 = termFreq=2.0), product of:
      0.7079  queryWeight, product of:
        2.9105  idf(docFreq=147, maxDocs=1000)
        0.2432  queryNorm
      2.0581  fieldWeight in 127, product of:
        1.4142  tf(freq=2.0), with freq of:
          2.0000  termFreq=2.0
        2.9105  idf(docFreq=147, maxDocs=1000)
        0.5000  fieldNorm(doc=127)
  1.0255  weight(tags:kids in 127) [DefaultSimilarity], result of:
    1.0255  score(doc=127,freq=1.0 = termFreq=1.0), product of:
      0.7063  queryWeight, product of:
        2.9038  idf(docFreq=148, maxDocs=1000)
        0.2432  queryNorm
      1.4519  fieldWeight in 127, product of:
        1.0000  tf(freq=1.0), with freq of:
          1.0000  termFreq=1.0
        2.9038  idf(docFreq=148, maxDocs=1000)
        0.5000  fieldNorm(doc=127)

Ok! But still, there’s a lot going on in there. Let’s try and break it down.

  • 2.4824 is the total score for this single search result. As our query contained two terms, ‘movies’ and ‘kids’, Lucene breaks the overall query down into two subqueries.
  • The sum of the two subqueries (1.4570 for ‘movies’ and 1.0255 for ‘kids’) are added to arrive at our total score.

For our first subquery, the ‘movies’ part, we arrive at the score of 1.4570 by multiplying queryWeight (0.709) by fieldWeight (2.0581). Let’s go line by line:

  1.4570  weight(tags:movies in 127) [DefaultSimilarity], result of:
The total score for the ‘movies’ subquery is 1.4570. ‘tags:movies‘ is the raw query, 127 is the individual document number we’re examining, and DefaultSimilarity is the scoring mecahsnism we’re using.
1.4570 score(doc=127,freq=2.0 = termFreq=2.0), product of:
The term (‘movies‘) appears twice in the ‘tags‘ field for document 127, so we get a term frequency of 2.0
0.7079 queryWeight, product of:
queryWeight (0.7079) is how rare the search term is within the whole index – in our case, ‘movies‘ appears in 147 out of the 1000 documents in our index.   This normalization factor is the same for all results returned by our query and just stops the queryWeight scores from becoming too exaggerated for any single result.
2.9105 idf(docFreq=147, maxDocs=1000)
  This rarity is called inverse document frequency (idf)
0.2432 queryNorm
  .. and is itself multiplied by a normalization factor (0.2432) called queryNorm.

This normalization factor is the same for all results returned by our query and just stops the queryWeight scores from becoming too exaggerated for any single result.

2.0581 fieldWeight in 127, product of:
  fieldWeight (2.0581) is how often the search term (‘movies‘) appears in the field we searched on ‘tags’.
1.4142 tf(freq=2.0), with freq of:
  2.0000 termFreq=2.0
  We take the square root of the termFreq (2.0) = 1.4142
2.9105 idf(docFreq=147, maxDocs=1000)
  This is multiplied by the idf which we calculated above (2.9105)
0.5000 fieldNorm(doc=127)
   and finally by a field normalization factor (0.5000), which tells us how many overall terms were in the field.

This ‘boost‘ value will be higher for shorter fields – meaning the more promenant your search term was in a field, the more relevant the result.

Further reading:

Happy Lucene hacking!

Returning JSON errors from Sitecore MVC controllers

ASP.NET MVC gives us IExceptionFilter, with which we can create custom, global exception handlers to apply to controller actions.

public class ExceptionLoggingFilter : FilterAttribute, IExceptionFilter
	public void OnException(ExceptionContext filterContext)
		// filterContext now contains lots of information about our exception, controller, action, etc
		UserAgent = filterContext.HttpContext.Request.UserAgent;


We can apply this filter to all Action methods, by adding our filter to the list of global filters:

public class FilterConfig {
	public static void RegisterGlobalFilters(GlobalFilterCollection filters) {
		filters.Add(new ExceptionLoggingFilter());


and wiring this up to our application in our Application_Start method:



In Sitecore

As you may expect, Sitecore exposes this functionality as pipeline processors. Sitecore defined a custom IExceptionFilter implementation (see our snippet above) which kicks off the mvc.exception pipeline, passing along the ExceptionContext object.

As client developers, it is our job to create an appropriate processor to accept the ExceptionContext and do something with it. Let’s run through an example where we want to return a JSON representation of the error, loaded with as much useful information as possible.

For more reading on Sitecore controller actions returning JSON, have a look at John West’s post here:

So, first up, create an empty handler class, which inherits from ExceptionProcessor:

public class JSONExceptionHandler :
	public override void Process(Sitecore.Mvc.Pipelines.MvcEvents.Exception.ExceptionArgs args)



Create a Web.config include, to add this processor to the mvc.exception pipeline:

<configuration xmlns:patch="">
        <processor type="Bleep.Handlers.JSONExceptionHandler, Bleep.Handlers"/>


Ok! Now our JSONExceptionHandler class will be called each time an exception occurs in MVC code. So, let’s grab all the detail we can from the ExceptionContext class and return it as JSON:

public override void Process(Sitecore.Mvc.Pipelines.MvcEvents.Exception.ExceptionArgs args)
	var filterContext = args.ExceptionContext;
	filterContext.Result = new JsonResult
		JsonRequestBehavior = JsonRequestBehavior.AllowGet,
                  Data = new
    			Message = filterContext.Exception.Message,
    			StackTrace = filterContext.Exception.StackTrace,
    			Controller = filterContext.Controller.GetType().Name,
    			Result = filterContext.Result.GetType().Name,
    			UserAgent = filterContext.HttpContext.Request.UserAgent,
    			ItemName = args.PageContext.Item.Name,
    			Device = args.PageContext.Device.DeviceItem.Name,
    			User = filterContext.HttpContext.User.Identity.Name
	filterContext.ExceptionHandled = true;
	// Log the error
	Sitecore.Diagnostics.Log.Error("MVC exception processing " 
                	+ Sitecore.Context.RawUrl, args.ExceptionContext.Exception, this);


This will produce a result such as:


Happy hacking!

A workaround for missing ViewData in Sitecore MVC

Passing data between Sitecore renderings can get tricky.

Sending messages between sibling renderings can lead us to worry about the order in which they render, and you may end up with renderings tightly coupled to other renderings. Jeremy Davis discusses ways to switch the order of rendering execution on his blog here:


Pass data down, not across

My preferred approach is for renderings to be as isolated as possible and not need to talk to siblings. In a regular MVC site, we would instantiate a ViewModel, and pass it down to any child (or partial) views as needed. If a child view doesn’t change this ViewModel at all, we don’t have to worry about order of execution or changes of state.

In Sitecore, we can achieve this by wrapping child renderings in a parent Controller Rendering. This Controller Rendering creates and prepares the ViewModel, and then passes it down to one or more child renderings.


Let’s recap on the main points here:

  1. Our parent Controller Rendering creates and prepares a ViewModel. This parent specifies a view, which contains one or more placeholders.
  2. This ViewModel is passed along to any child renderings currently attached to the placeholders.
  3. During execution, child renderings do not modify the ViewModel. We may even consider the ViewModel immutable while rendering takes place.

Sitecore has a peculiarity here which makes our job difficult. Each rendering gets a new instance of ViewData – explained by Kern Herskind Nightingale here: This puts a stop to us using ViewData to pass our ViewModel down from the parent rendering to child renderings.

The Workaround

There’s a way you can ensure that ViewData is correctly passed down from parent to child renderings. Let’s go through how this is possible.

  1. In your top level controller, create a ViewModel, which will be passed down to all child renderings.
public ActionResult ParentContainer()
    var viewModel = new {PageSize = 3, CurrentPage = 2, Results = Sitecore.Context.Item.Fields["Results"].Value};
    return View();

  1. Add it to the ViewData collection in the current ViewContext
public ActionResult ParentContainer()
    var viewModel = new {PageSize = 3, CurrentPage = 2, Results = Sitecore.Context.Item.Fields["Results"].Value};
    ContextService.Get().GetCurrent().ViewData.Add("_SharedModel", viewModel);
    return View();
  1. In each child rendering, fetch the ViewModel and add it to the local ViewData for the current rendering (which will be empty at this point). View Renderings will do this step for you, so you don’t need to do anything special there
public ActionResult ChildRendering()
    // Get any ViewData previously added to this ViewContext
    var contextViewData = ContextService.Get().GetCurrent().ViewData;
    contextViewData.ToList().ForEach(x => ViewData.Add(x.Key, x.Value));
    return View();
  1. Et voila! You now have access to the same ViewModel for each of your child renderings.
    Layout = null;
    var viewModel = ViewData["_SharedModel"];

Making it better

MVC offers us even better tools to remove code duplication. If you have a lot of child renderings needing access to your shared ViewModel, adding the code in step 3 will happen a lot. Let’s refactor that to an filter attribute.

public class RetrieveViewDataFilter : ActionFilterAttribute, IActionFilter
    public void OnActionExecuting(ActionExecutingContext filterContext)
        //Merge ViewData from context
        var contextViewData = ContextService.Get().GetCurrent().ViewData;
        contextViewData.ToList().ForEach(x => filterContext.Controller.ViewData.Add(x.Key, x.Value));

    public void OnActionExecuted(ActionExecutedContext filterContext)

Now, we just need to add this attribute to any Action Methods who may want to access shared ViewData from higher up in the stack

public ActionResult ChildRendering()
    return View();

There we go. I’m sure Sitecore will amend their implementation at some point, but until then, we have an immutable, single direction ViewData flow.