From 898b61a3a0deb406588f89920f4b2d53f76abbba Mon Sep 17 00:00:00 2001
From: Jeremy Ruston <174761+Jermolene@users.noreply.github.com>
Date: Thu, 31 Aug 2023 09:18:36 +0100
Subject: [PATCH] Experimental debug view

---
 core/modules/debug-view.js      | 54 +++++++++++++++++++++++++++++++++
 core/modules/filters.js         |  8 +++++
 core/modules/startup/startup.js |  2 ++
 3 files changed, 64 insertions(+)
 create mode 100644 core/modules/debug-view.js

diff --git a/core/modules/debug-view.js b/core/modules/debug-view.js
new file mode 100644
index 000000000..c4bb2176f
--- /dev/null
+++ b/core/modules/debug-view.js
@@ -0,0 +1,54 @@
+/*\
+title: $:/core/modules/debug-view.js
+type: application/javascript
+module-type: global
+
+debug-view module supports the optional external debug window
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+var dm = $tw.utils.domMaker;
+
+/*
+Instantiate the debug view
+*/
+function DebugView(options) {
+	if($tw.browser) {
+		this.outputFilters = dm("div",{
+			text: "Yes"
+		})
+		this.container = dm("div",{
+			"class": "tc-debug-view",
+			children: [
+				dm("div",{
+					children: [
+						dm("h1",{
+							text: "TiddlyWiki Debug View"
+						}),
+						dm("h2",{
+							text: "Filter Execution"
+						}),
+						this.outputFilters
+					]
+				})
+			]
+		});
+		document.body.appendChild(this.container);
+	}
+}
+
+/*
+Show a generic network error alert
+*/
+DebugView.prototype.displayError = function(msg,err) {
+	
+};
+
+exports.DebugView = DebugView;
+
+})();
diff --git a/core/modules/filters.js b/core/modules/filters.js
index 1bb5fe9ff..3a3be8194 100644
--- a/core/modules/filters.js
+++ b/core/modules/filters.js
@@ -330,6 +330,14 @@ exports.compileFilter = function(filterString) {
 			}
 		})());
 	});
+	// If we're debugging then wrap each operation function with debug code
+	if(true) {
+		$tw.utils.each(operationFunctions,function(operationFunction,index) {
+			operationFunctions[index] = function(results,source,widget) {
+				return operationFunction(results,source,widget);
+			};
+		});
+	}
 	// Return a function that applies the operations to a source iterator of tiddler titles
 	var fnMeasured = $tw.perf.measure("filter: " + filterString,function filterFunction(source,widget) {
 		if(!source) {
diff --git a/core/modules/startup/startup.js b/core/modules/startup/startup.js
index e0990228f..ba1e0a52d 100755
--- a/core/modules/startup/startup.js
+++ b/core/modules/startup/startup.js
@@ -23,6 +23,8 @@ var PERFORMANCE_INSTRUMENTATION_CONFIG_TITLE = "$:/config/Performance/Instrument
 var widget = require("$:/core/modules/widgets/widget.js");
 
 exports.startup = function() {
+	// Debug view
+	$tw.debugView = new $tw.DebugView();
 	// Minimal browser detection
 	if($tw.browser) {
 		$tw.browser.isIE = (/msie|trident/i.test(navigator.userAgent));