Sitecore 10.1 brings new Items-as-Resources option, which raises plenty of questions.
Please find the answers below:
- What it that used for?
- Why did we get it at all?
- Any concerns of using that?
1. Before 10.1 you’ve been given the initial set of OOB items upon the installation in the databases. That includes default templates, layouts, workflows and the rest of scaffolding items.
2. Now with 10.1 all these are supplied as the resources files outside of database. That's correct: all these items are no longer residing in the database. Yes, you still have them in your content tree as normal.
3. Does databases come empty? Not actually - there are just two entries for the default site (page) you normally first see after successful Sitecore instance installation, at the root of URL. It was decided not to put these into resources, as most customers delete that default home page anyway.
4. Are these resource read-only? Yes, Sitecore cannot write back into those resource files. Treat it as if they're written on CD but with an immediate access.
5. So does that mean I cannot modify default OOB items in Sitecore anymore? No, you actually can edit those as normal after "Unprotecting item" from a Content Editor ribbon. What happens in that case is Sitecore will take the delta between initial value stored in resource file and your changes and will store that delta having only changes you’ve done in the database. On item "consumption" the current state of item gets calculated from a resource file and that delta.
6. But you cannot delete these items. Sitecore prompts that it origins from the resource file therefore cannot be deleted. Still good, as leaves less potential for silly errors, anyway..
7. So where are these resource files located? They are based (quite predictably) within App_Data folder -
App_Data\items\<DATABASE_NAME>\items.<DATABASE_NAME>.dat (by default).
8. What format are these resource files? Protobuff (Protocol Buffers) from Google. That is a surprisingly old format which is proven for a decade, at least.
9. How can I create my own resources?
Officially - you cannot. Well, it is technically possible but requires very deep dive into Protocol Buffers, raw database storage and investigating new data provider in Sitecore. But, Sitecore will likely start providing authors of popular modules with the toolset to create such a resources with an ease. So, let's say for SXA you will no longer need installing SPE + SXA packages yourself, instead you'll simply drop the resource files provided by SXA team underneath
items folder, not even need to publish that afterwards.
10. Why no need publishing? That's because you copy the resource file for web database as well - items are alredy on the web database. Of course, all the items created by you will still need to get published.
11. But why at all Sitecore introduced that?
The main reason is to simplify the platform version upgrade process. The way update is done has changed.
You may have notice on the Sitecore download page, "Upgrade options" section have changed: instead of Sitecore Update Packages you now have Sitecore UpdateApp Tool that operates against each specific version you'd want to upgrade from. This tool will remove the default items for each particular legacy version and replace it with the resource files, Of course it also updates the schema with the changes which was already available.
12. The bigger reason for this change was "think containers - think ahead" approach. With such a change it becomes easier to upgrade version of Sitecore when running in containers: everything from the database since now is entirely user's custom data, and can be entirely copied to a never database, while version-specific-and-system-related items get updated by just a resource file substitute.
13. Also you may heard that Fast Query has been deprecated. That is exact reason why - if something isn't in the database, Sitecore cannot efficiently build the graph of the relationship for fast query
14. What is that data provider mentioned above?
That is a new one called
CompositeDataProvider that inherited by
DefaultDataProvider. The name composite assumes that one cares of merging items for Sitecore tree from both DB and the resources. In the configuration you specify it for an individual database under <database> section, you can also change the location for such resources by patching
<filePath> node of
<protobutItems> and overriding the location.
15. For the end-consumer of DataProvider (high level of stack) nothing changes as they still use
DefaultDataProvider from their code. The changes occur at intermediate level and those happen to be internal for Sitecore.
16. That actually opens up a much wider potential for creating some intemediate-level providers to things other than ProtoBuf and SQL Databases: CRMs, DAMs, some other headless CMSs maybe. In any case this is very important and greatly welcomed step ahead for the platform!
Update: there is another great blog post from my MVP-colleague Jeremy Davis on that same topic, where he also tried drilling into these resurce files with ProtoBuff.Net library.