Expose manifest params JSON

controllers/params.mjs

@@ -0,0 +1,10 @@
+'use strict';
+
+import Common from '../src/common.js';
+
+/**
+ * Show all possible parameters for manifest URLs
+ */
+export default async function exposeParams() {
+    return await Common.getParamsFromFolders();
+}

routes/index.mjs

@@ -1,6 +1,7 @@
 import generateManifest from '../controllers/manifest.mjs';
 import generateCanvas from '../controllers/canvas.mjs';
 import generateSequence from '../controllers/sequence.mjs';
+import exposeParams from '../controllers/params.mjs';
 import express from 'express';
 
 let router = express.Router();
@@ -26,5 +27,9 @@ router.get('/iiif/:manifestid/sequence/:name', async function(req, res) {
 	res.json(sequence);
 });
 
+/* GET possible params for manifest responses */
+router.get('/params', async function(req, res) {
+	res.json(await exposeParams());
+});
 
-export default router;
+export default router;

src/common.js

@@ -43,6 +43,24 @@ function extractDNOMetadata(imgFilename) {
 		date: '',
 	}
 }
+/**
+ * Retrieves available image techniques
+ * for all papyruses based on folder contents
+ * @returns {object}
+ */
+Common.getParamsFromFolders = async function() {
+	let params = {};
+	const papyri = await fs.promises.readdir(process.env.IMAGES_DIR);
+
+	for (let p of papyri) {
+		params[p] = [];
+		for (let tech of await fs.promises.readdir(`${process.env.IMAGES_DIR}/${p}`)) {
+			params[p].push(tech.toLowerCase().replaceAll('_','-'));
+		}
+	}
+
+	return params;
+}
 /**
  * @param {string} manifestId 
  */