Add very basic support for finding and rendering templates

express/basic/routes.ts

@@ -0,0 +1,18 @@
+import { DateTime } from "ts-luxon";
+import type { Call, Result, Route } from "../types";
+import { html, render } from "../util";
+
+const routes: Record<string, Route> = {
+    hello: {
+        path: "/hello",
+        methods: ["GET"],
+        handler: async (call: Call): Promise<Result> => {
+            const now = DateTime.now();
+            const c = await render("basic/hello", { now });
+
+            return html(c);
+        },
+    },
+};
+
+export { routes };

express/routes.ts

@@ -3,6 +3,7 @@
 import nunjucks from "nunjucks";
 import { DateTime } from "ts-luxon";
 import { authRoutes } from "./auth/routes";
+import { routes as basicRoutes } from "./basic/routes";
 import { contentTypes } from "./content-types";
 import { multiHandler } from "./handlers";
 import { httpCodes } from "./http-codes";
@@ -24,6 +25,7 @@ const okText = (result: string): Result => {
 
 const routes: Route[] = [
     ...authRoutes,
+    basicRoutes.hello,
     {
         path: "/slow",
         methods: ["GET"],

express/util.ts

@@ -0,0 +1,36 @@
+import { readFile } from "node:fs/promises";
+import nunjucks from "nunjucks";
+import { contentTypes } from "./content-types";
+import { executionContext } from "./execution-context";
+import { httpCodes } from "./http-codes";
+import type { Result } from "./types";
+
+// FIXME: Handle the error here
+const loadFile = async (path: string): Promise<string> => {
+    // Specifying 'utf8' returns a string; otherwise, it returns a Buffer
+    const data = await readFile(path, "utf8");
+
+    return data;
+};
+
+const render = async (path: string, ctx: object): Promise<string> => {
+    const fullPath = `${executionContext.diachron_root}/templates/${path}.html.njk`;
+
+    const template = await loadFile(fullPath);
+
+    const retval = nunjucks.renderString(template, ctx);
+
+    return retval;
+};
+
+const html = (payload: string): Result => {
+      const retval: Result = {
+        code: httpCodes.success.OK,
+        result: payload,
+        contentType: contentTypes.text.html,
+    };
+
+    return retval;
+};
+
+export { render, html };