The migration extension's OTP application. It supervises every mishka_installer plugin the
extension ships (plugins/0). A plugin registers on the event it listens on once it is supervised
here.
The plugins are the sources (sources/0, each a plugin on "migration:sources", see
MishkaCmsMigration.Source) and the targets (targets/0, each on "migration:targets", see
MishkaCmsMigration.Target) it ships; the one that makes it installable on a site,
MishkaCmsMigration.Provision; the admin page's sidebar entry,
MishkaCmsMigrationWeb.SidebarMenu; and the runs' log in the core's activity log
(MishkaCmsMigration.Activity, on "activity:sources").
At boot it also attaches the Oban telemetry handler that fails the run of a migration job Oban
discards (MishkaCmsMigration.Workers.attach/0).
The migration jobs run on the host's Oban, on a migration queue the host declares; the host
starts Oban through AshOban.config/2 with its ash_domains, which refuses to start without the
queue. Each site has one run dry running or importing at a time
(MishkaCmsMigration.MigrationRun's :one_active_per_site); the queue's limit is how many sites
migrate at once across the whole installation. With
queues: [migration: 1] one site migrates while the others' jobs wait their turn; a host with
many sites may raise it, at the cost of that many imports writing at the same time.
Summary
Functions
The kinds the Blog targets write, known where the Blog is not loaded: an item of one of them whose
target is not installed waits for an admin's decision, Wait for the Blog or Leave out
("blog_missing", MishkaCmsMigration.Workers.Helpers.Decision), rather than being skipped as a
kind nothing imports.
Every mishka_installer plugin this extension ships, all of which start/2 supervises. A plugin
left out of it never registers, so the event it listens on never reaches it.
The sources this extension ships, each a plugin on "migration:sources": WordPress over its REST
API (MishkaCmsMigration.Sources.WordPress) and from its export file
(MishkaCmsMigration.Sources.WordPressFile).
The targets this extension ships, each a plugin on "migration:targets" writing one kind of item
through an existing CMS action: files into the CMS's media library
(MishkaCmsMigration.Targets.CmsMedia), the site's name and pictures into its settings
(MishkaCmsMigration.Targets.CmsSetting), Elementor's global colours and fonts into a stylesheet
of theme tokens (MishkaCmsMigration.Targets.CmsStylesheet), pages into the CMS's pages
(MishkaCmsMigration.Targets.CmsPage), the main menu into the links of the site layout's header
(MishkaCmsMigration.Targets.CmsLayout),
authors, categories, tags, posts and comments into Mishka Blog
(MishkaCmsMigration.Targets.BlogBlogger, MishkaCmsMigration.Targets.BlogCollection,
MishkaCmsMigration.Targets.BlogTag, MishkaCmsMigration.Targets.BlogPost,
MishkaCmsMigration.Targets.BlogComment), and each post's old address into a CMS redirect to it
(MishkaCmsMigration.Targets.PostRedirect).
Functions
@spec blog_kinds() :: [String.t()]
The kinds the Blog targets write, known where the Blog is not loaded: an item of one of them whose
target is not installed waits for an admin's decision, Wait for the Blog or Leave out
("blog_missing", MishkaCmsMigration.Workers.Helpers.Decision), rather than being skipped as a
kind nothing imports.
@spec plugins() :: [module()]
Every mishka_installer plugin this extension ships, all of which start/2 supervises. A plugin
left out of it never registers, so the event it listens on never reaches it.
@spec sources() :: [module()]
The sources this extension ships, each a plugin on "migration:sources": WordPress over its REST
API (MishkaCmsMigration.Sources.WordPress) and from its export file
(MishkaCmsMigration.Sources.WordPressFile).
@spec targets() :: [module()]
The targets this extension ships, each a plugin on "migration:targets" writing one kind of item
through an existing CMS action: files into the CMS's media library
(MishkaCmsMigration.Targets.CmsMedia), the site's name and pictures into its settings
(MishkaCmsMigration.Targets.CmsSetting), Elementor's global colours and fonts into a stylesheet
of theme tokens (MishkaCmsMigration.Targets.CmsStylesheet), pages into the CMS's pages
(MishkaCmsMigration.Targets.CmsPage), the main menu into the links of the site layout's header
(MishkaCmsMigration.Targets.CmsLayout),
authors, categories, tags, posts and comments into Mishka Blog
(MishkaCmsMigration.Targets.BlogBlogger, MishkaCmsMigration.Targets.BlogCollection,
MishkaCmsMigration.Targets.BlogTag, MishkaCmsMigration.Targets.BlogPost,
MishkaCmsMigration.Targets.BlogComment), and each post's old address into a CMS redirect to it
(MishkaCmsMigration.Targets.PostRedirect).
Mishka Blog is an optional dependency, and each Blog target is defined only where it is loaded,
so on a node without it they are left out, and the items of their kinds (blog_kinds/0) wait for
the Blog ("blog_missing").