= Metadata SPI

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The metadata SPIs allow the framework to obtain metadata from alternative locations.


.Metadata SPIs
[cols="2m,4a",options="header"]
|===

|API
|Description




|xref:refguide:applib:index/services/grid/GridLoaderService.adoc[GridLoaderService]
|Responsible for loading a grid layout for a domain class, eg from a `layout.xml` file.


|xref:refguide:applib:index/services/grid/GridService.adoc[GridService]
|A facade on top of both xref:refguide:applib:index/services/grid/GridLoaderService.adoc[GridLoaderService] and
xref:refguide:applib:index/services/grid/GridSystemService.adoc[GridSystemService], thus being able to return normalized grids for any domain class.



|xref:refguide:applib:index/services/grid/GridSystemService.adoc[GridSystemService]
|Validates and normalizes the grid layout for a domain class (with respect to a particular grid system such as Bootstrap), also providing a default grid (for those domain classes where there is no grid layout).



|xref:refguide:applib:index/services/menu/MenuBarsLoaderService.adoc[MenuBarsLoaderService]
|Low-level SPI to load the serialized form of the menubars (normally: the `menubars.layout.xml`) into memory.
Used by


|xref:refguide:applib:index/services/menu/MenuBarsService.adoc[MenuBarsService]
|Constructs and normalizes the in-memory representation of the menubars.


|xref:refguide:applib:index/services/i18n/TranslationsResolver.adoc[TranslationsResolver]
|Obtain translations for a particuar phrase and locale, in support of i18n (ie so that the app's UI, messages and exceptions can be translated to the required locale by the xref:refguide:applib:index/services/i18n/TranslationService.adoc[TranslationService]



|===



