Breaking change: component identifier format

[marlo-longley]

I branched off Chris's work on this in a branch from last year. Closes #1318

This PR will have 2 parts (will undraft after both are in):

1. create a seam for customizing the identifier format
2. change the default format (breaking change)

I also drafted text for a wiki entry on how to use the new traject setting, and how to customize in order to keep the old format after this breaking change.

[marlo-longley]

Here is the text of the wiki that I wrote -- to publish when we do a release [edited based on Sean's work]

component_identifier_format in ArcLight

ArcLight has default configuration for how IDs are minted for components from an EAD. These are used internally in the application for navigation. As of a breaking change in version 1.xxxx ?, the default format for component IDs includes an undesrcore: <root_id>_<ref_id> . Here root_id is the root EAD document, and ref_id is a particular component in the hierarchy. In practice this looks something like umich-bhl-851981_aspace_ffa8f2e89cab96c9fa8c25b55ddb1e16.

How to customize component_identifier_format

(This is also the process to retain the default format that existed prior to 1.xxxxx)

Provide the component_identifier_format setting in the ead2_component_config.rb file. You need to provide this as a Ruby “named format string”.

Our default looks like this: (provide link to code line)

provide 'component_identifier_format', '%<root_id>s_%<ref_id>s'

Examples of customization:

• If instead of umich-bhl-851981_aspace_ffa8f2e89cab96c9fa8c25b55ddb1e16 , you want aspace_ffa8f2e89cab96c9fa8c25b55ddb1e16 (no root prefix), you could provide the following traject setting:

provide 'component_identifier_format', '%<ref_id>s'

• If you want to retain the previous default format, you could provide the following traject setting (no underscore):

provide 'component_identifier_format', '%<root_id>s%<ref_id>s’

For implementers upgrading to 1.xxxx

• To incorporate the changes of 1.xxxx and start to use underscores in your component IDs, you will need to run a full reindex because these IDs are stored in Solr. Without doing this, navigating an EAD tree of components will break with routes not found (ArcLight will be looking for http://localhost:3000/catalog/aoa271_aspace_24d96d896c187b4e90ebb6c910f0462f when your component is stored as http://localhost:3000/catalog/aoa271aspace_24d96d896c187b4e90ebb6c910f0462f).

• To retain the old-style IDs, do not run a reindex. Instead, customize the component_identifier_format as described above to remove the underscore.

[marlo-longley]

I also wanted to include this from @randalldfloyd from Slack since it gives good context for the breaking change:

-- If someone pulls in this breaking change, they will have to run a reindex to get the new underscores into their documents.

[seanaery]

This is looking really great, @marlo-longley. I got thinking about the complexity of having to override that Parent.global_id method in addition to changing the format in the traject config and thought it'd be ideal to only have to specify this setting in one place.

I branched off your branch (see identifier-format-no-global-id) and made one modest commit that looks to me like it works:
1035486

Curious what you think.

[marlo-longley]

@seanaery thanks so much for digging into this. Your work is a big improvement in my opinion! For reducing codebase complexity and also for implementers using this new setting. I will update my wiki text accordingly. I updated the wiki text above.

I tested your branch and all looks good.

I am fine if you wanted to push your commit to this branch/PR, or PR your branch -- not sure the best way.

[seanaery]

@marlo-longley Sounds great -- in that case I will cherry-pick my commit into this branch and push it back up so this PR remains the one under review (it'll just have three contributors now).