From d1171128c60e1f9f124c8a951a71a4609cd8bd1f Mon Sep 17 00:00:00 2001
From: Simon Hoxbro <simon.hansen@me.com>
Date: Sat, 12 Dec 2020 15:30:28 +0100
Subject: [PATCH 1/2] Fixing enable and disable file download

---
 panel/models/file_download.ts | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/panel/models/file_download.ts b/panel/models/file_download.ts
index 6bca0526b3..3f338121d1 100644
--- a/panel/models/file_download.ts
+++ b/panel/models/file_download.ts
@@ -1,6 +1,7 @@
 import {InputWidget, InputWidgetView} from "@bokehjs/models/widgets/input_widget"
 
 import {bk_btn, bk_btn_type} from "@bokehjs/styles/buttons"
+import {input} from "@bokehjs/core/dom"
 
 import {ButtonType} from "@bokehjs/core/enums"
 import * as p from "@bokehjs/core/properties"
@@ -34,6 +35,8 @@ export class FileDownloadView extends InputWidgetView {
   _prev_href: string | null = ""
   _prev_download: string | null = ""
 
+  protected input_el: HTMLInputElement
+
   initialize(): void {
     super.initialize()
     if ( this.model.data && this.model.filename ) {
@@ -47,6 +50,7 @@ export class FileDownloadView extends InputWidgetView {
     this.connect(this.model.properties.filename.change, () => this._update_download())
     this.connect(this.model.properties._transfers.change, () => this._handle_click())
     this.connect(this.model.properties.label.change, () => this._update_label())
+    this.connect(this.model.properties.disabled.change, () => this.set_disabled())
   }
 
   render(): void {
@@ -96,6 +100,12 @@ export class FileDownloadView extends InputWidgetView {
       this.anchor_el.addEventListener("click", this._click_listener)
     }
     this.group_el.appendChild(this.anchor_el)
+
+    this.input_el = input({
+      type: "bk_btn, bk_btn_type",
+      disabled: this.model.disabled,
+    })
+    this.input_el.addEventListener("change", () => this.change_input())
   }
 
   _increment_clicks() : void {
@@ -166,6 +176,14 @@ export class FileDownloadView extends InputWidgetView {
       }
     }
   }
+
+  set_disabled(): void {
+    if (this.model.disabled){
+      this.anchor_el.setAttribute("disabled", "")
+    } else {
+      this.anchor_el.removeAttribute("disabled")
+    }
+  }
 }
 
 export namespace FileDownload {

From 9b2a2362d73b2687132352090fa576204c516775 Mon Sep 17 00:00:00 2001
From: Simon Hoxbro <simon.hansen@me.com>
Date: Sat, 12 Dec 2020 15:40:36 +0100
Subject: [PATCH 2/2] Added comment

---
 panel/models/file_download.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/panel/models/file_download.ts b/panel/models/file_download.ts
index 3f338121d1..5ba4a50c46 100644
--- a/panel/models/file_download.ts
+++ b/panel/models/file_download.ts
@@ -101,9 +101,12 @@ export class FileDownloadView extends InputWidgetView {
     }
     this.group_el.appendChild(this.anchor_el)
 
+    // If this is not added it will give the following error
+    // "Uncaught TypeError: t is undefined"
+    // This seems to be related to button do not have a value
+    // property.
     this.input_el = input({
       type: "bk_btn, bk_btn_type",
-      disabled: this.model.disabled,
     })
     this.input_el.addEventListener("change", () => this.change_input())
   }