# Upgrading a host from 0.4 to 0.7 This page says what a host changes to move `statifier_datamodel` from 0.4.0 to 0.7.0, one minor at a time: 0.4 to 0.5, the 0.5.1 and 0.5.2 patches, then 0.5 to 0.6 and 0.6 to 0.7. A host here is the code that embeds the package: the datamodel documents it writes, the calls it makes to `StatifierDatamodel.Index`, `StatifierDatamodel.Document`, `StatifierDatamodel.Declarations`, `StatifierDatamodel.Types`, `StatifierDatamodel.Compatibility`, `StatifierDatamodel.Coverage` and `StatifierDatamodel.Conformance`, and any relation of its own it wraps around the read check. What each release added is in [CHANGELOG.md](../CHANGELOG.md); this page lists only what a host has to do about it, and says **NONE** where the answer is nothing. Move the pin with each minor, as the README recommends: `{:statifier_datamodel, "~> 0.7.0"}`. The Elixir requirement (`~> 1.18`) is the same on every step of this page, and the package still has no runtime dependencies. A host that takes this package through `statifier_blocks` or `statifier_ui` need not move either of them with it: statifier_blocks from 0.35.0 through 0.43.0 and statifier_ui from 0.10.1 through 0.11.0 each require `~> 0.4`, which admits 0.5, 0.6 and 0.7. ## 0.4 to 0.5 Must change: **NONE**. 0.5.0 adds one module and one shipped file and changes no existing signature or answer: `StatifierDatamodel.Index.index/1` answers exactly as before for every document, and no module other than the new one gains or loses a function. May start doing: - **Validate a document before you index it.** The package now ships a hand-written draft-07 JSON Schema of the version-1 datamodel document, `priv/schemas/datamodel-document.schema.json`, in the tarball a host fetches. `StatifierDatamodel.Schema.path/0` answers where it is installed and `StatifierDatamodel.Schema.json/0` answers its text (the text, not a decoded map). Hand it to the draft-07 validator your own language already has. The schema is advisory: nothing in the package calls it, and it is deliberately stricter than `index/1`, so a document the schema rejects still indexes as it always did. What it rejects is yours to read and to give a severity; the `StatifierDatamodel.Schema` documentation lists the kinds of slip it catches. Worth knowing, with no change to make: - **If you wrap `StatifierDatamodel.Types.satisfies/3` in a relation of your own**, the `StatifierDatamodel.Types` documentation now states the rule such a wrapper keeps: whenever `satisfies/3` answers not-satisfied, the wrapper answers not-satisfied too. It also says reasons in `t:StatifierDatamodel.Types.reason/0` may be added as records take decisions, so match the reasons you render and send anything else to a default clause. No reason was added or re-spelled in 0.5.0; this is documentation of what a wrapper may rely on, not a change to the check. ## 0.5.0 to 0.5.1 Must change: **NONE**. 0.5.1 is a documentation release: the code and the shipped schema are unchanged from 0.5.0. `~> 0.5.0` already takes it. ## 0.5.1 to 0.5.2 Must change: **NONE**. 0.5.2 is a documentation release: the code and the shipped schema are unchanged from 0.5.1. `~> 0.5.0` already takes it. ## 0.5 to 0.6 Must change: **NONE**. 0.6.0 adds one public function and changes no existing signature: `StatifierDatamodel.Index.index/1` and `StatifierDatamodel.Index.path_types/1` answer exactly as before for every document. May start doing: - **Ask a type expression for its value kind.** `StatifierDatamodel.Types.value_kind/1` answers the expression language's value kind for a type expression: `:string`, `:number` for `:integer` and `:decimal`, and `:boolean`, `:date`, `:datetime` and `:duration` as themselves, with `nil` for `:object`, `:list` and every type that is not one of the nine. It is the answer `path_types/1` gives, which now reads its kinds from it. Worth knowing, with no change to make: - **If you validate documents against the shipped JSON Schema**, it now rejects a scope whose `label` or `description` is not a string, and a declaration whose `name` or `label` is not a string. The schema stays advisory, and `index/1` admits and answers for every document exactly as before. ## 0.6 to 0.7 Must change: **NONE**, unless a document of yours already carries a top-level `events` or `sends` key of its own. 0.7.0 adds three modules and two optional document keys; `Index`, `Document`, `Declarations`, `Types` and `Coverage` answer exactly as before for every document. If a document of yours carries a top-level key named `events` or `sends` (your own annotation, until now), the new events index reads it, and the shipped JSON Schema rejects either key when it is not a list of entries. Rename that key in the document, or rewrite it as a list of entries, each a map carrying a non-empty `name` and `type` and an optional `label` and `note`. The package never refused a document for it and still does not: only the schema's verdict and what the new index reads change. May start doing: - **Declare the events a chart receives and sends.** The optional `events` and `sends` keys list entries carrying a `name`, a payload `type` (one of the nine, or a declared record or shape) and an optional `label` and `note`. `StatifierDatamodel.Events.from_document/1` indexes them in list order, keeping the first occurrence of a name; `fetch/3` reads one entry; `unresolved/1` lists the entries whose type names nothing the document declares, which are typed `:unknown` and never refused. An entry missing `name` or `type` is dropped. - **Check a value against a type.** `StatifierDatamodel.Conformance.conforms/3` answers `:ok` or `{:error, mismatches}` for a value, such as an event payload decoded from JSON or built in Elixir, each mismatch a `{path, reason}` with `reason` either `:missing` or `{:expected, type}`. - **Check the paths a chart's conditions read.** `StatifierDatamodel.Reads.undeclared/2` answers the reads a document does not declare, each with its location and a reason. The how-to guide [Check the paths a chart's conditions read](guides/check-chart-reads.md) shows the host's half, which lists each condition's reads with the expression language and hands them in as data; this package still takes no dependency on it. Worth knowing, with no change to make: - **If you validate documents against the shipped JSON Schema**, it gains the optional `events` and `sends` properties. A document without either key validates as before.