Fine-tune your language fallback configuration

Version:

Depending on your Sitecore solution, you can make a few adjustments to your language fallback configuration, including to the search index and to language fallback settings using a patch file.

Set up a search index to handle language fallback

If your solution relies on Sitecore’s content search (item buckets) and you want to use language fallback, you must set up the particular search index to handle item- or field-level fallback.

To set up a search index to handle language fallback:

Enable the relevant fallback modes by adding (or patching) the following XML child elements for the relevant search index and setting their inner value to true. Apply these changes using a patch file. The patch file can have any name and must be placed in the /platform/ folder of your source code.

<index id="sitecore_master_index" …>
…
   <enableItemLanguageFallback>true</enableItemLanguageFallback>
   <enableFieldLanguageFallback>true</enableFieldLanguageFallback>
…
</index>

Perform a full rebuild of the affected indexes.

Note

If your configuration file does not contain these elements, use the Sitecore.ContentSearch.Solr.Index.Master.config file as an example of how to apply them.

No data is added to the index if there is no version of the field in the fallback language. However, in this case, the Sitecore data API returns items with fallback field values, and therefore we recommend that you enforce version presence on these items.

Configure the Sitecore.LanguageFallback.config file

You can configure the following settings by using a patch file to override the defaults in Sitecore.LanguageFallback.config. The patch file can have any name and must be placed in the /platform/ folder of your source code.

DefaultCacheSize - determines the default cache size that stores the language fallback field values. The default value is 20MB.

    <!--  CACHING - LANGUAGE FALLBACK FIELD VALUES - DEFAULT CACHE SIZE
    Determines the default size of the cache that stores the language fallback field values.
           Specify the value in bytes or append the value with KB, MB or GB.
              Default value: 20MB.
    -->
      <setting name="Caching.LanguageFallbackFieldValues.DefaultCacheSize" value="20MB" />

If you want different cache sizes on a specific database, use the following code sample. The sample is available in the configuration file.

    <!-- EXAMPLE: Override the size of languageFallbackFieldValues cache per database -->
    <!--
    <databases>
      <database id="master">
        <cacheSizes hint="setting">
          <languageFallbackFieldValues>20MB</languageFallbackFieldValues>
        </cacheSizes>
      </database>      
    </databases>
    -->

AllowVaryFallbackSettingsPerLanguage - enables you to have different fallback settings for the same field in different languages. The default value is false.

Important

If you enable this feature, performance is considerably degraded.

     <!--  LANGUAGE FIELD FALLBACK - ALLOW VARY FALLBACK SETTINGS PER LANGUAGE
              If set to 'true', then values from both versioned 'Enable Language Fallback' and shared 'Enable Shared Language Fallback' checkbox fields
              on the field definition item are used to determine whether language fallback functionality should be enabled for the corresponding field.
              It allows you to have different fallback settings for the same field in different content languages.
              Example: when 'en-CA' tries to fallback to 'en', the checkbox field will be retrieved from the field definition item in 'en-CA',
              thus such version should exist. If retrieved value is 'false', then the 'Enable Shared Language Fallback' checkbox field is used.
              Note: enabling this feature has negative impact on performance.
              If set to 'false', only the shared 'Enable Shared Language Fallback' checkbox field on the field definition item is used to determine whether
              language fallback functionality should be enabled for the corresponding field.
              Default value: false.
      -->
      <setting name="LanguageFieldFallback.AllowVaryFallbackSettingsPerLanguage" value="false" />

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