From 6e655cb0e0fdf0d52681d12ee96e14d11d21fcc8 Mon Sep 17 00:00:00 2001
From: Jason Kelly <jason.kelly@lingumi.com>
Date: Sun, 23 May 2021 14:12:00 +0800
Subject: [PATCH] Added new widget to alert if a file is set at larger than 10
 MB.

- Updated default widget to use template that adds a notification box.
- Added JS to add onchange & load events to look at the value in the input and trigger the notification & disable the form submits.
---
 bookwyrm/models/fields.py                     | 15 ++++++++
 bookwyrm/static/js/bookwyrm.js                | 35 +++++++++++++++++++
 .../clearable_file_input_with_warning.html    |  3 ++
 3 files changed, 53 insertions(+)
 create mode 100644 bookwyrm/templates/widgets/clearable_file_input_with_warning.html

diff --git a/bookwyrm/models/fields.py b/bookwyrm/models/fields.py
index 123b3efa..d4d94aa2 100644
--- a/bookwyrm/models/fields.py
+++ b/bookwyrm/models/fields.py
@@ -9,6 +9,7 @@ from django.contrib.postgres.fields import ArrayField as DjangoArrayField
 from django.core.exceptions import ValidationError
 from django.core.files.base import ContentFile
 from django.db import models
+from django.forms import ClearableFileInput, ImageField
 from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
 from bookwyrm import activitypub
@@ -332,6 +333,14 @@ class TagField(ManyToManyField):
         return items
 
 
+class ClearableFileInputWithWarning(ClearableFileInput):
+    template_name = 'widgets/clearable_file_input_with_warning.html'
+
+
+class CustomImageField(ImageField):
+    widget = ClearableFileInputWithWarning
+
+
 def image_serializer(value, alt):
     """helper for serializing images"""
     if value and hasattr(value, "url"):
@@ -395,6 +404,12 @@ class ImageField(ActivitypubFieldMixin, models.ImageField):
         image_content = ContentFile(response.content)
         return [image_name, image_content]
 
+    def formfield(self, **kwargs):
+        return super().formfield(**{
+            'form_class': CustomImageField,
+            **kwargs,
+        })
+
 
 class DateTimeField(ActivitypubFieldMixin, models.DateTimeField):
     """activitypub-aware datetime field"""
diff --git a/bookwyrm/static/js/bookwyrm.js b/bookwyrm/static/js/bookwyrm.js
index 3659a20e..2c43d738 100644
--- a/bookwyrm/static/js/bookwyrm.js
+++ b/bookwyrm/static/js/bookwyrm.js
@@ -3,6 +3,7 @@
 
 let BookWyrm = new class {
     constructor() {
+        this.MAX_FILE_SIZE = 10000000
         this.initOnDOMLoaded();
         this.initReccuringTasks();
         this.initEventListeners();
@@ -32,15 +33,26 @@ let BookWyrm = new class {
                 'click',
                 this.back)
             );
+
+        document.querySelectorAll('input[type="file"]')
+            .forEach(node => node.addEventListener(
+                'change',
+                this.disableIfTooLarge.bind(this)
+            ));
     }
 
     /**
      * Execute code once the DOM is loaded.
      */
     initOnDOMLoaded() {
+        const bookwyrm = this
+
         window.addEventListener('DOMContentLoaded', function() {
             document.querySelectorAll('.tab-group')
                 .forEach(tabs => new TabGroup(tabs));
+            document.querySelectorAll('input[type="file"]').forEach(
+                bookwyrm.disableIfTooLarge.bind(bookwyrm)
+            )
         });
     }
 
@@ -284,4 +296,27 @@ let BookWyrm = new class {
             node.classList.remove(classname);
         }
     }
+
+    disableIfTooLarge(eventOrElement) {
+        const { addRemoveClass, MAX_FILE_SIZE } = this
+        const element = eventOrElement.currentTarget || eventOrElement
+
+        const submits = element.form.querySelectorAll('[type="submit"]')
+        const warns = element.parentElement.querySelectorAll('.file-too-big')
+        const isTooBig = element.files &&
+            element.files[0] &&
+            element.files[0].size > MAX_FILE_SIZE
+
+        if (isTooBig) {
+            submits.forEach(submitter => submitter.disabled = true)
+            warns.forEach(
+                sib => addRemoveClass(sib, 'is-hidden', false)
+            )
+        } else {
+            submits.forEach(submitter => submitter.disabled = false)
+            warns.forEach(
+                sib => addRemoveClass(sib, 'is-hidden', true)
+            )
+        }
+    }
 }
diff --git a/bookwyrm/templates/widgets/clearable_file_input_with_warning.html b/bookwyrm/templates/widgets/clearable_file_input_with_warning.html
new file mode 100644
index 00000000..700e22f9
--- /dev/null
+++ b/bookwyrm/templates/widgets/clearable_file_input_with_warning.html
@@ -0,0 +1,3 @@
+{% load i18n %}
+{% include "django/forms/widgets/clearable_file_input.html" %}
+<span class="help file-cta is-hidden file-too-big">{% trans "File exceeds maximum size: 10MB" %}</span>