starting to add batch code heading

docs/BatchCodeSelectInitializer.js

@@ -1,15 +1,28 @@
 class BatchCodeSelectInitializer {
 
-    static initialize({batchCodeSelectElement, batchCodeDetailsElement}) {
+    static initialize({ batchCodeSelectElement, batchCodeDetailsElement, batchCodeHeadingElement }) {
         const batchCodeDetailsView = new BatchCodeDetailsView(batchCodeDetailsElement);
         batchCodeSelectElement.select2({ minimumInputLength: 4 });
         batchCodeSelectElement.on(
             'select2:select',
             function (event) {
-                const batchcode = event.params.data.id;
-                batchCodeDetailsView.displayBatchCodeDetails(batchcode);
-                GoogleAnalytics.click_batchcode(batchcode);
+                BatchCodeSelectInitializer.#onBatchCodeSelected(
+                    {
+                        batchcode: event.params.data.id,
+                        batchCodeHeadingElement: batchCodeHeadingElement,
+                        batchCodeDetailsView: batchCodeDetailsView
+                    });
             });
         batchCodeSelectElement.select2('open');
     }
+
+    static #onBatchCodeSelected({ batchcode, batchCodeHeadingElement, batchCodeDetailsView }) {
+        CompanyByBatchcodeProvider
+            .getCompany(batchcode)
+            .then(company => {
+                batchCodeHeadingElement.innerText = `Batch ${batchcode} (${company})`;
+                batchCodeDetailsView.displayBatchCodeDetails(batchcode);
+                GoogleAnalytics.click_batchcode(batchcode);
+            });
+    }
 }

docs/CompanyByBatchcodeProvider.js

@@ -0,0 +1,8 @@
+class CompanyByBatchcodeProvider {
+
+    static getCompany(batchcode) {
+        return fetch(`data/histograms/Global/${batchcode}.json`)
+            .then(response => response.json())
+            .then(histoDescrs => histoDescrs.Company);
+    }
+}