From 96eca32b1105416c317101aa91dd284f835a8ba8 Mon Sep 17 00:00:00 2001
From: Lee Sheng Long <github@sll.ee>
Date: Fri, 31 Jan 2020 20:13:28 +1100
Subject: [PATCH] Add download button/link to binary tiddler warning banners in
 view and edit mode (#4423)

---
 core/modules/parsers/binaryparser.js | 55 +++++++++++++++++++++++++---
 core/modules/widgets/edit-binary.js  | 55 +++++++++++++++++++++++++---
 core/ui/BinaryWarning.tid            |  4 --
 3 files changed, 98 insertions(+), 16 deletions(-)

diff --git a/core/modules/parsers/binaryparser.js b/core/modules/parsers/binaryparser.js
index ebfd2beec..fb3d38678 100644
--- a/core/modules/parsers/binaryparser.js
+++ b/core/modules/parsers/binaryparser.js
@@ -3,7 +3,7 @@ title: $:/core/modules/parsers/binaryparser.js
 type: application/javascript
 module-type: parser
 
-The video parser parses a video tiddler into an embeddable HTML element
+The binary parser parses a binary tiddler into a warning message and download link
 
 \*/
 (function(){
@@ -13,14 +13,57 @@ The video parser parses a video tiddler into an embeddable HTML element
 "use strict";
 
 var BINARY_WARNING_MESSAGE = "$:/core/ui/BinaryWarning";
+var EXPORT_BUTTON_IMAGE = "$:/core/images/export-button";
 
 var BinaryParser = function(type,text,options) {
-	this.tree = [{
-		type: "transclude",
+	// Transclude the binary data tiddler warning message
+	var warn = {
+		type: "element",
+		tag: "p",
+		children: [{
+			type: "transclude",
+			attributes: {
+				tiddler: {type: "string", value: BINARY_WARNING_MESSAGE}
+			}
+		}]
+	};
+	// Create download link based on binary tiddler title
+	var link = {
+		type: "element",
+		tag: "a",
 		attributes: {
-			tiddler: {type: "string", value: BINARY_WARNING_MESSAGE}
-		}
-	}];
+			title: {type: "indirect", textReference: "!!title"},
+			download: {type: "indirect", textReference: "!!title"}
+		},
+		children: [{
+			type: "transclude",
+			attributes: {
+				tiddler: {type: "string", value: EXPORT_BUTTON_IMAGE}
+			}
+		}]
+	};
+	// Set the link href to external or internal data URI
+	if(options._canonical_uri) {
+		link.attributes.href = {
+			type: "string", 
+			value: options._canonical_uri
+		};
+	} else if(text) {
+		link.attributes.href = {
+			type: "string", 
+			value: "data:" + type + ";base64," + text
+		};
+	}
+	// Combine warning message and download link in a div
+	var element = {
+		type: "element",
+		tag: "div",
+		attributes: {
+			class: {type: "string", value: "tc-binary-warning"}
+		},
+		children: [warn, link]
+	}
+	this.tree = [element];
 };
 
 exports["application/octet-stream"] = BinaryParser;
diff --git a/core/modules/widgets/edit-binary.js b/core/modules/widgets/edit-binary.js
index cf2e2ad2c..a4a18f63d 100644
--- a/core/modules/widgets/edit-binary.js
+++ b/core/modules/widgets/edit-binary.js
@@ -13,6 +13,7 @@ Edit-binary widget; placeholder for editing binary tiddlers
 "use strict";
 
 var BINARY_WARNING_MESSAGE = "$:/core/ui/BinaryWarning";
+var EXPORT_BUTTON_IMAGE = "$:/core/images/export-button";
 
 var Widget = require("$:/core/modules/widgets/widget.js").widget;
 
@@ -43,13 +44,55 @@ EditBinaryWidget.prototype.render = function(parent,nextSibling) {
 Compute the internal state of the widget
 */
 EditBinaryWidget.prototype.execute = function() {
-	// Construct the child widgets
-	this.makeChildWidgets([{
-		type: "transclude",
+	// Get our parameters
+	var editTitle = this.getAttribute("tiddler",this.getVariable("currentTiddler"));
+	var tiddler = this.wiki.getTiddler(editTitle);
+	var type = tiddler.fields.type;
+	var text = tiddler.fields.text;
+	// Transclude the binary data tiddler warning message
+	var warn = {
+		type: "element",
+		tag: "p",
+		children: [{
+			type: "transclude",
+			attributes: {
+				tiddler: {type: "string", value: BINARY_WARNING_MESSAGE}
+			}
+		}]
+	};
+	// Create download link based on draft tiddler title
+	var link = {
+		type: "element",
+		tag: "a",
 		attributes: {
-			tiddler: {type: "string", value: BINARY_WARNING_MESSAGE}
-		}
-	}]);
+			title: {type: "indirect", textReference: "!!draft.title"},
+			download: {type: "indirect", textReference: "!!draft.title"}
+		},
+		children: [{
+		type: "transclude",
+			attributes: {
+				tiddler: {type: "string", value: EXPORT_BUTTON_IMAGE}
+			}
+		}]
+	};
+	// Set the link href to internal data URI (no external)
+	if(text) {
+		link.attributes.href = {
+			type: "string", 
+			value: "data:" + type + ";base64," + text
+		};
+	}
+	// Combine warning message and download link in a div
+	var element = {
+		type: "element",
+		tag: "div",
+		attributes: {
+			class: {type: "string", value: "tc-binary-warning"}
+		},
+		children: [warn, link]
+	}
+	// Construct the child widgets
+	this.makeChildWidgets([element]);
 };
 
 /*
diff --git a/core/ui/BinaryWarning.tid b/core/ui/BinaryWarning.tid
index c6e8d3139..bbf7aef66 100644
--- a/core/ui/BinaryWarning.tid
+++ b/core/ui/BinaryWarning.tid
@@ -1,8 +1,4 @@
 title: $:/core/ui/BinaryWarning
 
 \define lingo-base() $:/language/BinaryWarning/
-<div class="tc-binary-warning">
-
 <<lingo Prompt>>
-
-</div>