From 881d8b8d9540cfecba60acb42ab1e1d2cd6a5d8d Mon Sep 17 00:00:00 2001
From: John McLear <john@mclear.co.uk>
Date: Fri, 6 Nov 2020 13:48:59 +0000
Subject: [PATCH] pluginfw: Hook to include additional body in HTML exports
 (#4469)

* hook, needs docs

* docs
---
 doc/api/hooks_server-side.md | 18 ++++++++++++++++++
 src/node/utils/ExportHtml.js |  5 +++++
 2 files changed, 23 insertions(+)

diff --git a/doc/api/hooks_server-side.md b/doc/api/hooks_server-side.md
index 224d3c7e4..33188fa9c 100644
--- a/doc/api/hooks_server-side.md
+++ b/doc/api/hooks_server-side.md
@@ -661,6 +661,24 @@ function _analyzeLine(alineAttrs, apool) {
 }
 ```
 
+## exportHTMLAdditionalContent 
+Called from: src/node/utils/ExportHtml.js
+
+Things in context:
+
+1. padId
+
+This hook will allow a plug-in developer to include additional HTML content in the Body of the exported HTML
+
+Example:
+```
+exports.exportHTMLAdditionalContent = async (hookName, context) => {
+  let padId = context;
+  return "I am groot in " + padId;
+}
+
+```
+
 ## stylesForExport
 Called from: src/node/utils/ExportHtml.js
 
diff --git a/src/node/utils/ExportHtml.js b/src/node/utils/ExportHtml.js
index 2c5a2c213..665e3d7eb 100644
--- a/src/node/utils/ExportHtml.js
+++ b/src/node/utils/ExportHtml.js
@@ -498,6 +498,11 @@ exports.getPadHTMLDocument = async function (padId, revNum)
 
   let html = await getPadHTML(pad, revNum);
 
+  let exportHTMLAdditionalContent = await hooks.aCallAll("exportHTMLAdditionalContent", padId);
+  exportHTMLAdditionalContent.forEach(function(hookHtml){
+    html += hookHtml;
+  });
+
   return eejs.require("ep_etherpad-lite/templates/export_html.html", {
     body: html,
     padId: Security.escapeHTML(padId),