Wayfinder.Engine.Journey 0.1.0

Wayfinder.Engine.Journey

A default, optional single-actor journey surface — server-rendered GOV.UK markup for "get my current stage, advance it" against one blueprint. The applicant/citizen counterpart to Wayfinder.Engine.Worklist's multi-item caseworker queue: one actor, one instance, one page — no list, no pickup/putback, no separate advance sub-route.

Usage

builder.Services.AddJourney(options =>
{
    options.ResolveTenantId = _ => "my-tenant";
    options.ResolveAccessProfile = _ => MyActors.CitizenProfile();
    options.RenderPage = (title, body, ctx) => PageShell.Render(title, body, ctx.User);
});

// ...

app.MapJourney("/apply", "my-blueprint-key", "Apply for a thing").RequireAuthorization("Applicant");
app.MapJourney("/premium", "another-blueprint-key", "Model a premium").RequireAuthorization("Applicant");

AddJourney is called once — the tenant/actor/page-chrome resolution is normally the same across every journey a host maps. MapJourney is called once per blueprint a host wants a self-service journey for, each with its own prefix, blueprintKey, and page title.

MapJourney maps three routes under prefix:

• GET {prefix} — the current stage. Ambient GetCurrent, deliberately: an ordinary visit keeps showing a just-reached terminal stage forever (a returning citizen sees "Thank you", not a silently-reset blank form). Automatically renders a "Start a new one" link (customize the label via MapJourney's own optional startNewLabel parameter) whenever the current response is genuinely terminal — no blueprint content authoring needed for it.
• POST {prefix} — advances it (POST-redirect-GET back to the same URL, so a reload or a second tab never resubmits a stale stateVersion).
• GET {prefix}/new — the distinct "start a new one" affordance the link above points at (IProcessManager.GetCurrentOrStartFresh): reinstates a still-in-progress instance rather than abandoning it, only actually starting fresh once the existing one is genuinely terminal.

Why a separate package from Wayfinder.Engine.Worklist

Same underlying building blocks (GovUkStageJourney's rendering/form-coercion, Wayfinder.Engine.Http's file-upload handling, IProcessManager), but a genuinely different shape — one instance per actor rather than a shared queue of many — so it gets its own package rather than an awkward "worklist, but sometimes there's no list" branch inside that one.