CSS Grid Layout for Sitecore

It is copy of my article to keep everything in one place, initially published here.

Before reading this blog, I recommend familiarising yourself with CSS Grid Layout. I like this guide. Or if you prefer to learn it during play in game, try CSS Grid Garden.

Major part of Sitecore projects from my experience has either predefined preset of layouts(containers for components) or are based on basic components of CSS frameworks: rows and columns(e.g.: Bootstrap, Foundation and others).

First approach is clear and obvious, you have predefined list of possible layouts: single column, two equal columns, three equal columns, one narrow column one wide column and others. This approach works good, but when site editor would need some new layout, he would not be able to create it without help of a developer. After passing of some time you will get a lot of containers that are designed only to build grid system. And when you are creating new page it is hard to select right container control from bunch of “three column layouts”.

Second approach is more flexible. You have 2 generic controls: Row and Column. You can define column width, row height. Exactly, like you do with Bootstrap grid system. Difference is only that you set column and row parameters on the level of rendering parameters in Sitecore. By combination of different rows and columns, you would be able to get any layout you can imagine. And you have only two controls that respond for grid structure: row and column. You know exactly what they do and how they will behave in different situations. The back side of coin is difficulties in designing complex layout. You get dozen of rows and columns. You are able to manage them somehow in the Experience Editor, making time to time mistakes with adding components to the wrong placeholder. And you get mess in the layout details of your page. You see bunch of rows and columns in the list with absence of understanding what is inside of them and are they still in use?

Mixed path of first and second approaches can resolve some of their limitations. But misuse of it by site managers could create a mess.

CSS Grid layout offers a grid-based layout system, with rows and columns, making it easier to design web pages without having to use floats and positioning. It is supported by modern browsers:

sing CSS Grid allow you to get column/row layout without needs to include any additional frameworks. You can have only one container component per page in Sitecore. This component is configurable, you can set any amount of columns and rows, spacing between columns and rows, alignment.

I have created prototype of CSS Grid Layout for Sitecore.

You can try it by yourself:

1. Download Sitecore update package from AppVeyor
2. Install it using update installation wizard /sitecore/admin/UpdateInstallationWizard.aspx
3. You will be able to insert "Container" component /sitecore/layout/Renderings/CSSGrid/Container. Amount of columns and rows is configurable using rendering parameters.
4. Inside placeholder under "Container" component you will be able to insert any amount of "Item" components /sitecore/layout/Renderings/CSSGrid/Item. Location(row/column) and size(rows/columns) of “Item” component is configurable using rendering parameters (It is expected that all UI components will be compatible with Grid CSS and you will be able to place them inside container. And configure location/size/alignment using rendering parameters)

If you have any difficulties, refer to example how to use it.

Few screenshots, how it will work:

Using CSS Grid Layout for Sitecore we have got flexible layout for Sitecore project without mess in layout details. We have only one container for unlimited number of controls. Location of each control is configured by its rendering parameters. In the next part I will describe how to use this module in details.

P.S. If you are interested in free automated system that prepares Sitecore CSS Grid Layout package from GitHub sources, please read my article about possible CI/CD configuration for open source projects.

Stemming Search Terms in Sitecore Solr Indexes

It is copy of my article, initially published here to keep everything in one place.

I wrote about stemming in Sitecore Lucene content search in my previous article. But, just to remind you: Stemming is the process of reducing inflected (or sometimes derived) words to their word stem or root form. It allows you to make your search to return more relevant results. That is why usage of stemming could be a good and easy option to improve your search.

Configuring stemming in Solr is even easier than configuring it in Sitecore Lucene Content Search. You don’t need to write even one line of code. All you need is configuration.

There is schema.xml file in configuration of each Solr core. When you will open it you will see that there is field type text_en:

<fieldType name="text_en" class="solr.TextField" positionIncrementGap="100">
  <analyzer type="index">
 <tokenizer class="solr.StandardTokenizerFactory" />
 <filter class="solr.SynonymFilterFactory" synonyms="index_synonyms.txt" ignoreCase="true" expand="false"/>
 <filter class="solr.StopFilterFactory" ignoreCase="true" words="lang/stopwords_en.txt" />
 <filter class="solr.LowerCaseFilterFactory" />
 <filter class="solr.EnglishPossessiveFilterFactory" />
 <filter class="solr.KeywordMarkerFilterFactory" protected="protwords.txt" />
 <!-- Optionally you may want to use this less aggressive stemmer instead of PorterStemFilterFactory:
 <filter class="solr.EnglishMinimalStemFilterFactory"/>
        -->
 <filter class="solr.PorterStemFilterFactory" />
  </analyzer>
  <analyzer type="query">
 <tokenizer class="solr.StandardTokenizerFactory" />
 <filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true" />
 <filter class="solr.StopFilterFactory" ignoreCase="true" words="lang/stopwords_en.txt" />
 <filter class="solr.LowerCaseFilterFactory" />
 <filter class="solr.EnglishPossessiveFilterFactory" />
 <filter class="solr.KeywordMarkerFilterFactory" protected="protwords.txt" />
 <!-- Optionally you may want to use this less aggressive stemmer instead of PorterStemFilterFactory:
 <filter class="solr.EnglishMinimalStemFilterFactory"/>
        -->
 <filter class="solr.PorterStemFilterFactory" />
  </analyzer>
</fieldType>

It contains filter solr.PorterStemFilterFactory that do stemming of your indexed document and your query. Compared to Lucene.Net, you have three options what stemmer to use for English language: Porter, Lovins or Porter2. Also, you have the ability for stemming documents in different languages: Armenian, Basque, Catalan, Danish, Dutch, Finnish, French, German, Hungarian, Italian, Norwegian, Portuguese, Romanian, Russian, Spanish, Swedish, Turkish.

To use stemming on your field you should change its type from text_general to text_en:

<field name="_content" type="text_en" indexed="true" stored="false" />

Then you need to restart Solr and rebuild indexes. And this one small configuration change will improve search quality on your website.

Stemming Search Terms in Sitecore Lucene Indexes

    It is copy of my article, initially published here to keep everything in one place.

   Sitecore content search is great technology that allows you to get search on your Sitecore website with minimum efforts. But one thing that always disappointed me is that this search doesn’t understand word forms. Single and plural form of a noun will be saved as two separate terms in the index(e.g.: “tool” and “tools”). Single, past tense and normal form of a verb will result in three different terms in the index(e.g.: “deny”, “denies” and “denied”). It gives worse search results. If you will search “deny” then it would not found documents with “denies” or “denied”.

    There are few options how you can “fix” it. First one is usage of similarity parameter in the query: x => x.YourFieldName.Like(“tools”, 0.8f). It is quick and dirty solution. Now, content search will return results with similar words. But there is the other side of the coin. You will get search results with similar words where you don’t expect. E.g.: search for “Ireland” will give “Iceland” and “Island” in results.

    The other option is using “Stemming”. Stemming is the process of reducing inflected (or sometimes derived) words to their word stem. There are a different implementation of stemming algorithms. Lucene.Net has implementation of the Porter Stemming algorithm. It could be used to extend Sitecore content search. We need to implement our own analyser:

1 2 3 4 5 6 7 8 9 10 11 12 13 14

using Lucene.Net.Analysis; using System; using System.IO; namespace Feature.StemmedSearch.Search { public class PorterStemLowerCaseKeywordAnalyzer : KeywordAnalyzer { public override TokenStream TokenStream(string fieldName, TextReader reader) { return new PorterStemFilter(new LowerCaseFilter(new KeywordTokenizer(reader))); } } }

    Then register field mapping in the content search configuration:

<fieldNames>
  <field fieldName="_content"              storageType="YES" indexType="TOKENIZED"    vectorType="NO" boost="1f" type="System.String" settingType="Sitecore.ContentSearch.LuceneProvider.LuceneSearchFieldConfiguration, Sitecore.ContentSearch.LuceneProvider">
 <analyzer type="Feature.StemmedSearch.Search.PorterStemLowerCaseKeywordAnalyzer, Feature.StemmedSearch" />
  </field>
</fieldNames>

    I used _content field as example, but it is better don’t change Sitecore fields that come out of the box and use your own custom fields. Now, after rebuild of indexes we can see that all search terms are saved in a stemmed way:

    And when you check search queries by turning on verbose logging. You will see that search query terms are also stemmed for _content field:

Hurray! Now, our Sitecore website search is more similar to Google search. :-)

Stay tuned, in the second part we will do the same for Solr indexes.

CI/CD for Your Sitecore Pet Project Using AppVeyor

It is copy of my article placed in Sagittarius blog
There is lots of information about how to build continuous integration, continuous delivery and continuous deployment for enterprise Sitecore projects. But, none of these include information about Sitecore projects on GitHub with CI/CD (at least I haven’t faced with them). That is why I have decided to write a step-by-step guide on how to get CI/CD for your Sitecore pet project for free.
Let’s start:

1. Create accounts for GitHub and AppVeyor (using authorization via GitHub)
2. Create your Sitecore project and push it to GitHub
3. Create and push appveyor.yml file to your repository

#Version of project could be based on build number
version: 1.0.{build}
#Path(s) to artifacts. We will create Sitecore update package and ship it as artifact
artifacts:
  - path: build\artifacts\*.update
    name: Sitecore.Akamai
before_build:
  #Configure Nuget to use public Sitecore packages feed
  - nuget sources add -Name SitecorePublicFeed -Source https://sitecore.myget.org/F/sc-packages/api/v3/index.json
  #Restore packages configured in solution
  - nuget restore Sitecore.Akamai.sln
build:
  #Solution file
  project: Sitecore.Akamai.sln
#Configuration of deployment artifacts to GitHub as release. It is not possible to save artifacts on Appveyor due to limited time of storage (30 days)
after_build:
  #Run PowerShell script that will build .update Sitecore package
  - ps: .\build\build.ps1  
deploy:
  #Release name
  release: Sitecore.Akamai-v$(appveyor_build_version)
  #Description of release
  description: 'Using Akamai features inside Sitecore'
  #Deploy to GitHub
  provider: GitHub
  #Secure token to upload files to GitHub https://www.appveyor.com/docs/deployment/github/
  auth_token:
    secure: rkLSxUbN2YMMG/r6lzLq1PN0n07dqJBtk/8ZR2c/InGy0SBOsmqGXfIQWMQOZUAs 
  draft: false
  prerelease: false
  on:
    branch: master                # release from master branch only
    appveyor_repo_tag: true       # deploy on tag push only
install:
  #Intallation of Sitecore.Courier Powershell module to have ability to build Sitecore package
  - ps: Set-ExecutionPolicy Bypass -Scope Process -Force; iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'))
  #Intallation of Sitecore.Courier to have ability to build Sitecore package
  - choco install sitecore-courier

    4. Commit and push powershell script that will prepare Sitecore update package with files and items using Sitecore.Courier

#Get package version from Appveyor
$version = $env:APPVEYOR_BUILD_VERSION
if ($version -eq $null) {
    $version = "1.0.0"
}
"Package version: " + $version
 
#Clear build directories
Remove-Item build\package -Recurse -ErrorAction Ignore
Remove-Item build\artifacts -Recurse -ErrorAction Ignore
#Create directories structure for package
New-Item -Name build\package -ItemType directory
New-Item -Name build\artifacts -ItemType directory
New-Item -Name build\package\Data -ItemType directory
New-Item -Name build\package\bin -ItemType directory
New-Item -Name build\package\App_Config\Include\Foundation -ItemType directory
 
#Copy Sitecore items and assemblies to proper location
Copy-Item .\src\Foundation\Akamai\code\bin\Foundation.Akamai* .\build\package\bin
Copy-Item .\src\Foundation\Akamai\code\App_Config\Include\Foundation\Foundation.Sitecore.Akamai.config .\build\package\App_Config\Include\Foundation
Copy-Item .\src\Foundation\Akamai\serialization\* .\build\package\Data -recurse
 
#Run Sitecore Courier to prepare .update package
$packageCmd = "Sitecore.Courier.Runner.exe -t build\package -o build\artifacts\sitecore.akamai." + $version + ".update -r"
iex $packageCmd

   5. Add a new project to Appveyor from GitHub

   6. Configure the publishing of artifacts. Create a new GitHub token. Encrypt it using AppVeyor and update appveyor.yml with new encrypted value.

   7. Update readme.md file with badge of build status

That is all. After next commit to your GitHub repo, new AppVeyor build will be triggered and Sitecore update package will be prepared. Sitecore update package will be available from artifacts tab on build details page. New GitHub release will be created after the creation of the new tag in the repository. The release will contain an archive of source files and Sitecore .update package. Update package will contain files and items and could be installed on any Sitecore website using update installation wizard.

As a bonus, you can configure code metrics on Sonar Cloud for free:

1. Create a new Sonar Cloud account using GitHub authorization
2. Generate new Sonar Cloud token and encrypt it using AppVeyor
3. Change you appveyor.yml configuration:

before_build:
  #Start SonarQube runner
  - MSBuild.SonarQube.Runner.exe begin /k:"Sitecore.Akamai" /d:"sonar.host.url=https://sonarqube.com" /d:"sonar.login=%sonar_token%" /d:"sonar.organization=github-antonytm" /n:"Sitecore.Akamai"
after_build:
  #Stop SonarQube runner
  - MSBuild.SonarQube.Runner.exe end /d:"sonar.login=%sonar_token%"
  - ps: .\build\build.ps1  
environment:
  sonar_token:
    secure: xxx #Put your encrypted Sonar Cloud token here
install:
  #Install msbuild SonarQube runner
  - choco install "msbuild-sonarqube-runner" -y

     4. Update readme.md file with Sonar Cloud code quality badges.

It took some time to set up this configuration first time. But for the second project, it took less than half an hour. This free lightweight cloud CI/CD is a good investment in saving your time to avoid preparing new builds manually. And you should not necessarily select services described in this article. It is only one way that was shown as an example. GitHub could be replaced with Bitbucket, AppVeyor with TravisCI, etc.

You can see all this in action inside my repository on GitHub.

Sitecore and Akamai Hidden Gems, Part 2: Device Detection

     At the first part of Akamai article series I wrote how to utilize GeoIp data on Sitecore. Another useful information that could be provided by Akamai is device characteristics:

1. Akamai maintains database of useragent strings
2. When visitor requests your website under Akamai, it is able to parse useragent header on the fly and add parsed information about device. 
3. You get X-Akamai-Device-Characteristics request header on your server that contains information that could be used. E.g.: X-Akamai-Device-Characteristics: brand_name=Google; is_tablet=false; device_os=Android
4.  You can use this information to display different content depending on information that you have got.

    Sitecore code that respond for getting device characteristics is not easy to override comparing to GeoIp detection. But it is possible to build Sitecore rules that will parse Akamai headers. Here is example of "Device is Mobile" rule (real code looks differently, it is just example to have everything in one place for better understanding):

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Sitecore.Diagnostics;
using Sitecore.Rules;
using Sitecore.Rules.Conditions;

namespace Foundation.Akamai.DeviceDetection.Rules.Conditions
{
    public class DeviceIsMobile<T> : OperatorCondition<T> where T : RuleContext
    {
        private HeaderParser HeaderParser
        {
            get
            {
                return new HeaderParser();
            }
        }

        protected override bool Execute(T ruleContext)
        {
            Assert.ArgumentNotNull(ruleContext, "ruleContext");
            Assert.IsNotNullOrEmpty(HttpContext.Current.Request.Headers["X-Akamai-Device-Characteristics"], "Akamai header X-Akamai-Device-Characteristics is null or empty");
            var headerValue = HttpContext.Current.Request.Headers["X-Akamai-Device-Characteristics"];
            var dictionary = headerValue.ParseAkamaiHeader(";");
            bool.TryParse(dictionary["is_mobile"], out bool value);
            return value;
        }
    }

    public static class Extensions
    {
        public static Dictionary<string, string> ParseAkamaiHeader(this string headerValue, string delimiter = ",")
        {
            var pairs = headerValue.Split(new string[] { delimiter }, StringSplitOptions.RemoveEmptyEntries).Select(x => x.Trim());
            var dictionary = new Dictionary<string, string>();
            foreach (var pair in pairs)
            {
                var parts = pair.Split('=');
                if (parts.Length > 1)
                {
                    var key = parts[0];
                    var value = parts[1];
                    dictionary.Add(key, value);
                }
            }

            return dictionary;
        }
    }
}

    It is possible to create a lot of rules based on Akamai information about visitor location or his device without overriding anything in Sitecore.

   All code and Sitecore items serialization are available in GitHub repository, also it is possible to download Sitecore update package and use it.

Sitecore and Akamai Hidden Gems, Part 1: GeoIp Detection

    Akamai is well known CDN(content delivery network) provider. It provides content delivery features that are very widely used  across popular websites. Besides CDN, Akamai provides additional features, but not everyone is aware of them. One of them is providing GeoIp data. In brief, how it works:

1. Akamai maintains database of IP addresses
2. When user requests your website under Akamai, Akamai is able to parse IP address of request on the fly and add information about user’s geographic location, network, connection speed, etc. to request header. 
3. You get X-Akamai-Edgescape request header on your server that contains a lot of information that could be used. E.g.: X-Akamai-Edgescape: georegion=263,country_code=US,region_code=MA,city=CAMBRIDGE,dma=50 6,pmsa=1120,areacode=617,county=MIDDLESEX,fips=25017,lat=42.3933,l ong=-71.1333,timezone=EST,zip=02138-02142+02238-02239,continent=NA ,throughput=vhigh,asnum=21399
4. You are able parse this header and get more information about your visitor to show him relevant information on website

      Out of the box Sitecore also provides provides GeoIp personalization. Both Akamai and Sitecore GeoIp detection have it’s benefits. Akamai GeoIp is free(if you are already customer of Akamai) and could be quicker, because you don’t need to spent server time to get information about IP address. Sitecore GeoIp is ready to use out of the box and is better integrated with Sitecore Experience Platform. Depending on project you can prefer different GeoIp provider.

    If you choose Akamai then you are able to find article that describes how to do it. That solution works properly for Sitecore 6.6 - 7.2, but doesn’t work on Sitecore 8+. Since some time Sitecore moved parsing GeoIp headers to separate thread:

if (orCreate.GeoIpResolveState == GeoIpResolveState.Unresolved)
{
 GeoIpManager.StartResolvingThread(orCreate);
}

That thread doesn’t know nothing about your context, that is why call of HttpContext.Current.Request.Headers["X-Akamai-Edgescape"] causes “Object reference not set to an instance of an object” exception. It means that only overriding of LookupManager will not work. I have managed to transfer data from Akamai header to Sitecore analytics context in next way:

1. Disable Sitecore.Analytics.Pipelines.CommitSession.UpdateGeoIpData, Sitecore.Analytics.Pipelines.CreateVisits.UpdateGeoIpData and Sitecore.Analytics.Pipelines.EnsureClassification.UpdateGeoIpData processors
2. Override Sitecore.Analytics.Pipelines.StartTracking.UpdateGeoIpData processor

using Foundation.Akamai.GeoIp;

namespace Foundation.Akamai.Pipelines
{
    public class UpdateGeoIpData 
    {
        public void Process(object args)
        {
            var whois = new LookupProvider().GetInformationByIp("");
            if(whois!=null)
            {
                Sitecore.Analytics.Tracker.Current.Interaction.SetGeoData(whois);
            }
        }
    }
}

    This approach works, because parsing header is quick operation that doesn’t need running separate thread. As I understand four UpdateGeoIpData processors in different pipelines were required to sync thread that get GeoIp information with main HttpRequest thread.

    To get more details you can review my repository on GitHub or download package and try it by yourself.

Passing Sitecore Certified Platform Associate Developer

I passed  Sitecore Certified Platform Associate Developer exam. There are a lot of posts in the internet that describes topics and question that are present on exam. This post is not about it, furthermore it is not allowed. It is about technical issues that you can face(and I faced) during passing online exam:

• Be very attentive to time that you select for exam. I selected 3 PM, but I got invitation on 2 PM. I was confused and was ready to pass it on 2 PM, but exam started at 3 PM. I think that this issue is related to daylight-saving time zones issue in http://webassessor.com system.
• You can't check Sentinel Secure software before running exam. You should have backup plan if something will go wrong with your software/hardware.
• Sentinel Secure software throws error on Windows server 2012
• Sentinel Secure software doesn't work with all webcams. (I assume that issue is present for 4k cams)

You can ask me how I faced with all of these issues during passing exam:

1. I tried to start exam on 2 PM, but it was unavailable until 2:50 PM
2. I started exam on my laptop, but exam software was not able to see video from my camera. Video was black blank screen in application, however in other software camera worked as expected.
3. I moved to machine with Windows server 2012 R2 installed. I was not able even to start exam application. After checking system it wrote "Error" with one option: exit.
4. I moved back to laptop and tried different camera and fortunately it started to work.

Adding HtmlCache Viewing Feature to Sitecore.Rocks Visual Studio Extension

It is copy of my article placed in Sagittarius blog. 

After writing an article about viewing Sitecore HTML cache, I thought that it is not convenient to move custom code from one project to another. When, instead, there is ability to extend widely used existing Sitecore development tool Sitecore.Rocks then it should be done. I decided to contribute into it.

First of all, you need to fork Sitecore.Rocks project on GitHub.

    Sitecore.Rocks works like server-client application. You have server side (Sitecore.Rocks.Server, connector in other words) that is copied to all Sitecore websites and client side: interface in Visual Studio to display different things from Sitecore. Fortunately, there is already “Data” column for cache viewer to display cache details and we don’t need to modify interface to add something new. But this column shows only path to item, when cache key is Sitecore identifier. In all other cases Data column will be empty. Let’s extend amount of data that could be shown in this column.

     Logic that returns data to be displayed in this table located in /src/Sitecore.Rocks.Server/Requests/Caches/GetCacheKeys.cs file. We can modify it and add ability to return cache value when cache type is string or id:

    After building a solution, we need copy Sitecore.Rocks.Server.dll to bin folder of our website. Now, you are able to see what it inside cache. If you are interested in viewing other types of cache(not only string and id) then you are able to extend code above with your needs.

If my pull request is accepted, then this feature will be available in one of next Sitecore.Rocks version.

How to Check What is Inside Sitecore HTML Cache?

It is a copy of this blog post.

Sitecore has a lot of caches: AccessResultCache, DataCache, DeviceItemsCache, HTML cache, ItemCache, ItemPathsCache, PathCache, RegistryCache, RuleCache, StandardValuesCache, ViewStateCache, XslCache, FieldReaderCache and others. When you facing with caching issue on your website(something is either not cached, or cached but should not), it is important to have the ability to see what is present in cache.

All Sitecore caches consist of cache key and cache value. Cache key is always string. Cache value could be any type of object depending on cache. We can take as example HtmlCache cache. When you see what cache key you have and what data is there, you can better tune caching of controls, especially when you have custom(not out of the box) cache criterias (vary by IP, vary by country, vary by role, etc.) and a lot of controls on a page. Here is code snippet to get everything inside HtmlCache:
It requires using reflection due to private methods in HTML cache. The result of execution GetCaches method will be List<Tuple<string, string>>, that you can filter, make search or display on the page. It can save you a lot of time when debugging Sitecore caching issues. Here is an example of service page that displays cache keys and cache values:

If you can’t add this code to some secure page in your solution(you don’t want to do it or need some out of the box solution) then there are also other useful tools for troubleshooting issues with Sitecore cache. But they will not show you the cached value of HtmlCache entry:

• Sitecore Cache Admin - marketplace module.
• Sitecore Rocks - Visual studio extension for Sitecore. Cache viewing option is available from Sitecore 8.2.

Using WebP Format in Sitecore

It is a copy of this blog post to have all my articles in one place.
WebP is promising format that allows good optimization comparing to JPEG and PNG. According to tests it provides lossless images that are 26% smaller compared to PNGs and lossy images that are 25-34% smaller than comparable JPEG images at equivalent SSIM quality index.
This format becomes more and more popular over the web nowadays. Google promotes WebP format, it released WebP as open source to allow anyone works with it and suggest improvements. But, is it supported by major browsers? Going to CanIUse gives answer that not:

(support details are on 2018/01/21, it could be changed over time)

It is supported by Chrome, Opera, Chrome for Android. Safari and Firefox are experimenting(not supported yet) with supporting WebP images. IE and Edge doesn’t support it.
But how it can be used now, when not all browsers support it? Each browser(web client) provides Accept header when getting resources from server. If this header contains image/webp, web server know that it can returns WebP format. As example Akamai CDN use this behavior. It can return optimized WebP images for web clients who support it and JPEG and PNG for those who doesn’t support.
Let’s consider how it could be used in Sitecore. It has no sense to add support of WebP format to media library for now, we can’t return this file format to all web clients. But it makes sense to return WebP format to web clients that can use it. Saving about 25% of time on loading images can make big difference for user experience, especially on mobile. I decided don’t write new image optimizer from the scratch and add support of WebP to well known tool for images optimization for the Sitecore: Dianoga.
To make it works, we should get understanding how Sitecore Media Library and Sitecore Media Library cache work. Sitecore media library creates files on disk after each request, or uses previously created files. By default these files are located under \Website\App_Data\MediaCache\website\{some folders}. There are few files in each folder. First type of files is cache for image. It is image itself, Sitecore don’t need to preprocess width, height and other parameters for each media request. It does processing only once. Second type of files is .ini file, it is metadata for cached object. Metadata contains next values:
Key. e.g. ?as=False&bc=0&h=0&iar=False&mh=0&mw=0&sc=0&thn=False&w=0. Key contains all media query parameters.
Extension - extension of file.
Headers - cached headers that should be returned to web client
DataFile - file name of object that should be returned to web client.

We need to extend forming of key, to add one more parameter that will indicate support of WebP format. It will require extending of MediaRequestHandler:

public class MediaRequestHandler : Sitecore.Resources.Media.MediaRequestHandler
{
 protected override bool DoProcessRequest(HttpContext context, MediaRequest request, Media media)
 {
  if (context?.Request.AcceptTypes != null && (context.Request.AcceptTypes).Contains("image/webp"))
  {
   request.Options.CustomOptions["extension"] = "webp";
  }

  return base.DoProcessRequest(context, request, media);
 }

 private static bool AcceptWebP(HttpContext context)
 {
  return context?.Request.AcceptTypes != null && (context.Request.AcceptTypes).Contains("image/webp");
 }
}

Our key will contain one more additional parameter: extension. E.g.: ?as=False&bc=0&h=0&iar=False&mh=0&mw=0&sc=0&thn=False&w=0&extension=webp
Let’s add handler that will process WebP compatible requests based on
CommandLineToolOptimizer:

public class WebPOptimizer : CommandLineToolOptimizer
{
 public override void Process(OptimizerArgs args)
 {
  //If WebP optimization was executed then abort running other optimizers
  //because they don't accept webp input file format
  if (args.AcceptWebP)
  {
   base.Process(args);
   args.AbortPipeline();
  }
 }

 protected override string CreateToolArguments(string tempFilePath, string tempOutputPath)
 {
  return $"\"{tempFilePath}\" -o \"{tempOutputPath}\" ";
 }
}

It is very easy, it runs cwebp.exe tool that converts JPEG or PNG to WebP. It doesn’t utilize all available command line options, and could be tuned depending on requirements. All others code changes are more about Dianoga configuration and unit tests, I will not stop on them in this article. If you want more details, you can review all changes in GitHub repository.

How to enable Dianoga WebP support for your project:

1. Clone GitHub repository and build project
2. Enable Dianoga.WebP.config.disabled config
3. Open web.config and change line <add verb="*" path="sitecore_media.ashx" type="Sitecore.Resources.Media.MediaRequestHandler, Sitecore.Kernel" name="Sitecore.MediaRequestHandler" /> to <add verb="*" path="sitecore_media.ashx" type="Dianoga.MediaRequestHandler, Dianoga" name="Sitecore.MediaRequestHandler" />
4. If you have custom MediaRequestHandler (e.g. Habitat is used) then skip step 3 and override DoProcessRequest method with detection of support of WebP format. See MediaRequestHandler code listening above.

P.S. It is experimental feature, use it on your own risk. :-)

Use of Solr Search Provider in Sitecore

It is a copy of this blog post to have all my Sitecore articles in one place.

Usage of Solr search provider on Sitecore solutions becomes more and more popular. Solr is built over Lucene and provides additional abilities. Comparing with Lucene, it's server based:

• You don’t have a separate index for each CM/CD server, you don’t have problems with indexes sync on different machines
• CD servers doesn’t do indexes build, it frees server resources
• You are able to scale your search servers
• The more big your Sitecore solution is, the more probability is that you will use Solr provider.

Out of the box, Sitecore provides three types of Solr indexes: SolrSearchIndex, SwitchOnRebuildSolrSearchIndex and SwitchOnRebuildSolrCloudSearchIndex. SwitchOnRebuildSolrSearchIndex is built under top of SolrSearchIndex. SwitchOnRebuildSolrCloudSearchIndex is built under top of SwitchOnRebuildSolrSearchIndex. Why do you need different implementation? Answer is simple: SwitchOnRebuildSolrSearchIndex solves big problem of SolrSearchIndex: After start of index rebuild on SolrSearchIndex you temporarily get empty index. It causes seeing no search results by user during index rebuild.

SwitchOnRebuildSolrSearchIndex solves this problem by having 2 cores: one core is used during index rebuild, cores are swapped after rebuild, second core started to used after rebuild. It causes 2 requirements: having different core per index and double amount Solr cores. Swap atomically swaps the names used to access two existing cores. The prior core remains available and can be swapped back, if necessary. Each core will be known by the name of the other, after the swap.

Note: names of cores remains unchanged. Changing of places “sitecore_web_core” and “sitecore_web_core_rebuild” are only for highlighting that content of the core was changed by swap.

But what is happening when we are starting to use few SOLR servers: master and slave:

From diagram above we can make conclusion, that having “rebuild” cores could be redundant. And usage of SwitchOnRebuildSolrSearchIndex could be replaced with SolrSearchIndex, but we should disable replication during index rebuild. It could be easily done adding two Sitecore events:
Disabling replication on indexing:start. (if it is full index rebuild, not incremental)
Enabling replication on indexing:end. (if it is full index rebuild, not incremental)

Both these event handlers do web request to Solr server:

• http://master_host:port/solr/replication?command=disablereplication
• http://master_host:port/solr/replication?command=enablereplication

There is one un-obvious thing that you should have in mind: indexing:end event could be called when server is shutting down. It is necessary to check if server is not shutting down before enabling replication.

Now we get simpler process and possibility to use SolrSearchIndex.

Conclusion: when you have few Solr instances (Master/Slave) on Sitecore environments then you can use SolrSearchIndex and enabling/disabling replication instead of SwitchOnRebuildSolrSearchIndex.