Feature: user configurable list of allowed html tags in import

src/public/app/widgets/type_widgets/content_widget.js

@@ -25,6 +25,7 @@ import NoteErasureTimeoutOptions from "./options/other/note_erasure_timeout.js";
 import RevisionsSnapshotIntervalOptions from "./options/other/revisions_snapshot_interval.js";
 import RevisionSnapshotsLimitOptions from "./options/other/revision_snapshots_limit.js";
 import NetworkConnectionsOptions from "./options/other/network_connections.js";
+import HtmlImportTagsOptions from "./options/other/html_import_tags.js";
 import AdvancedSyncOptions from "./options/advanced/sync.js";
 import DatabaseIntegrityCheckOptions from "./options/advanced/database_integrity_check.js";
 import ConsistencyChecksOptions from "./options/advanced/consistency_checks.js";
@@ -94,7 +95,8 @@ const CONTENT_WIDGETS = {
         AttachmentErasureTimeoutOptions,
         RevisionsSnapshotIntervalOptions,
         RevisionSnapshotsLimitOptions,
-        NetworkConnectionsOptions
+        NetworkConnectionsOptions,
+        HtmlImportTagsOptions
     ],
     _optionsAdvanced: [
         DatabaseIntegrityCheckOptions,

src/public/app/widgets/type_widgets/editable_text.js

@@ -176,7 +176,15 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
         });
 
         this.watchdog.setCreator(async (elementOrData, editorConfig) => {
-            const editor = await editorClass.create(elementOrData, editorConfig);
+            const editor = await editorClass.create(elementOrData, {
+                ...editorConfig,
+                htmlSupport: {
+                    allow: JSON.parse(options.get("allowedHtmlTags")),
+                    styles: true,
+                    classes: true,
+                    attributes: true
+                }
+            });
 
             await initSyntaxHighlighting(editor);
 

src/public/app/widgets/type_widgets/options/other/html_import_tags.js

@@ -0,0 +1,84 @@
+import OptionsWidget from "../options_widget.js";
+import { t } from "../../../../services/i18n.js";
+
+// TODO: Deduplicate with src/services/html_sanitizer once there is a commons project between client and server.
+export const DEFAULT_ALLOWED_TAGS = [
+    'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'blockquote', 'p', 'a', 'ul', 'ol',
+    'li', 'b', 'i', 'strong', 'em', 'strike', 's', 'del', 'abbr', 'code', 'hr', 'br', 'div',
+    'table', 'thead', 'caption', 'tbody', 'tfoot', 'tr', 'th', 'td', 'pre', 'section', 'img',
+    'figure', 'figcaption', 'span', 'label', 'input', 'details', 'summary', 'address', 'aside', 'footer',
+    'header', 'hgroup', 'main', 'nav', 'dl', 'dt', 'menu', 'bdi', 'bdo', 'dfn', 'kbd', 'mark', 'q', 'time',
+    'var', 'wbr', 'area', 'map', 'track', 'video', 'audio', 'picture', 'del', 'ins',
+    'en-media', // for ENEX import
+    // Additional tags (https://github.com/TriliumNext/Notes/issues/567)
+    'acronym', 'article', 'big', 'button', 'cite', 'col', 'colgroup', 'data', 'dd',
+    'fieldset', 'form', 'legend', 'meter', 'noscript', 'option', 'progress', 'rp',
+    'samp', 'small', 'sub', 'sup', 'template', 'textarea', 'tt'
+];
+
+const TPL = `
+<div class="options-section">
+    <h4>${t("import.html_import_tags.title")}</h4>
+
+    <p>${t("import.html_import_tags.description")}</p>
+
+        <textarea class="allowed-html-tags form-control" style="height: 150px; font-family: monospace;" 
+                  placeholder="${t("import.html_import_tags.placeholder")}"></textarea>
+
+        <div class="form-text">
+            ${t("import.html_import_tags.help")}
+        </div>
+
+    <div>
+        <button class="btn btn-sm btn-secondary reset-to-default">
+            ${t("import.html_import_tags.reset_button")}
+        </button>
+    </div>
+</div>`;
+
+export default class HtmlImportTagsOptions extends OptionsWidget {
+    doRender() {
+        this.$widget = $(TPL);
+        this.contentSized();
+
+        this.$allowedTags = this.$widget.find('.allowed-html-tags');
+        this.$resetButton = this.$widget.find('.reset-to-default');
+
+        this.$allowedTags.on('change', () => this.saveTags());
+        this.$resetButton.on('click', () => this.resetToDefault());
+
+        // Load initial tags
+        this.refresh();
+    }
+
+    async optionsLoaded(options) {
+        try {
+            if (options.allowedHtmlTags) {
+                const tags = JSON.parse(options.allowedHtmlTags);
+                this.$allowedTags.val(tags.join(' '));
+            } else {
+                // If no tags are set, show the defaults
+                this.$allowedTags.val(DEFAULT_ALLOWED_TAGS.join(' '));
+            }
+        }
+        catch (e) {
+            console.error('Could not load HTML tags:', e);
+            // On error, show the defaults
+            this.$allowedTags.val(DEFAULT_ALLOWED_TAGS.join(' '));
+        }
+    }
+
+    async saveTags() {
+        const tagsText = this.$allowedTags.val();
+        const tags = tagsText.split(/[\n,\s]+/) // Split on newlines, commas, or spaces
+            .map(tag => tag.trim())
+            .filter(tag => tag.length > 0);
+
+        await this.updateOption('allowedHtmlTags', JSON.stringify(tags));
+    }
+
+    async resetToDefault() {
+        this.$allowedTags.val(DEFAULT_ALLOWED_TAGS.join('\n')); // Use actual newline
+        await this.saveTags();
+    }
+}

src/public/translations/en/translation.json

@@ -175,7 +175,14 @@
     "codeImportedAsCode": "Import recognized code files (e.g. <code>.json</code>) as code notes if it's unclear from metadata",
     "replaceUnderscoresWithSpaces": "Replace underscores with spaces in imported note names",
     "import": "Import",
-    "failed": "Import failed: {{message}}."
+    "failed": "Import failed: {{message}}.",
+    "html_import_tags": {
+      "title": "HTML Import Tags",
+      "description": "Configure which HTML tags should be preserved when importing notes. Tags not in this list will be removed during import.",
+      "placeholder": "Enter HTML tags, one per line",
+      "help": "Enter HTML tags to preserve during import. Some tags (like 'script') are always removed for security.",
+      "reset_button": "Reset to Default List"
+    }
   },
   "include_note": {
     "dialog_title": "Include note",

src/routes/api/options.ts

@@ -67,7 +67,8 @@ const ALLOWED_OPTIONS = new Set([
     'locale',
     'firstDayOfWeek',
     'textNoteEditorType',
-    'layoutOrientation'
+    'layoutOrientation',
+    'allowedHtmlTags' // Allow configuring HTML import tags
 ]);
 
 function getOptions() {

src/services/html_sanitizer.ts

@@ -1,5 +1,21 @@
 import sanitizeHtml from "sanitize-html";
 import sanitizeUrl from "@braintree/sanitize-url";
+import optionService from "./options.js";
+
+// Default list of allowed HTML tags
+export const DEFAULT_ALLOWED_TAGS = [
+    'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'blockquote', 'p', 'a', 'ul', 'ol',
+    'li', 'b', 'i', 'strong', 'em', 'strike', 's', 'del', 'abbr', 'code', 'hr', 'br', 'div',
+    'table', 'thead', 'caption', 'tbody', 'tfoot', 'tr', 'th', 'td', 'pre', 'section', 'img',
+    'figure', 'figcaption', 'span', 'label', 'input', 'details', 'summary', 'address', 'aside', 'footer',
+    'header', 'hgroup', 'main', 'nav', 'dl', 'dt', 'menu', 'bdi', 'bdo', 'dfn', 'kbd', 'mark', 'q', 'time',
+    'var', 'wbr', 'area', 'map', 'track', 'video', 'audio', 'picture', 'del', 'ins',
+    'en-media', // for ENEX import
+    // Additional tags (https://github.com/TriliumNext/Notes/issues/567)
+    'acronym', 'article', 'big', 'button', 'cite', 'col', 'colgroup', 'data', 'dd',
+    'fieldset', 'form', 'legend', 'meter', 'noscript', 'option', 'progress', 'rp',
+    'samp', 'small', 'sub', 'sup', 'template', 'textarea', 'tt'
+] as const;
 
 // intended mainly as protection against XSS via import
 // secondarily, it (partly) protects against "CSS takeover"
@@ -23,17 +39,18 @@ function sanitize(dirtyHtml: string) {
         }
     }
 
+    // Get allowed tags from options, with fallback to default list if option not yet set
+    let allowedTags;
+    try {
+        allowedTags = JSON.parse(optionService.getOption('allowedHtmlTags'));
+    } catch (e) {
+        // Fallback to default list if option doesn't exist or is invalid
+        allowedTags = DEFAULT_ALLOWED_TAGS;
+    }
+
     // to minimize document changes, compress H
     return sanitizeHtml(dirtyHtml, {
-        allowedTags: [
-            'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'blockquote', 'p', 'a', 'ul', 'ol',
-            'li', 'b', 'i', 'strong', 'em', 'strike', 's', 'del', 'abbr', 'code', 'hr', 'br', 'div',
-            'table', 'thead', 'caption', 'tbody', 'tfoot', 'tr', 'th', 'td', 'pre', 'section', 'img',
-            'figure', 'figcaption', 'span', 'label', 'input', 'details', 'summary', 'address', 'aside', 'footer',
-            'header', 'hgroup', 'main', 'nav', 'dl', 'dt', 'menu', 'bdi', 'bdo', 'dfn', 'kbd', 'mark', 'q', 'time',
-            'var', 'wbr', 'area', 'map', 'track', 'video', 'audio', 'picture', 'del', 'ins',
-            'en-media' // for ENEX import
-        ],
+        allowedTags,
         allowedAttributes: {
             '*': [ 'class', 'style', 'title', 'src', 'href', 'hash', 'disabled', 'align', 'alt', 'center', 'data-*' ]
         },

src/services/options_init.ts

@@ -136,7 +136,20 @@ const defaultOptions: DefaultOption[] = [
     // Text note configuration
     { name: "textNoteEditorType", value: "ckeditor-balloon", isSynced: true },
 
-    { name: "layoutOrientation", value: "vertical", isSynced: false }
+    // HTML import configuration
+    { name: "layoutOrientation", value: "vertical", isSynced: false },
+    { name: "allowedHtmlTags", value: JSON.stringify([
+        'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'blockquote', 'p', 'a', 'ul', 'ol',
+        'li', 'b', 'i', 'strong', 'em', 'strike', 's', 'del', 'abbr', 'code', 'hr', 'br', 'div',
+        'table', 'thead', 'caption', 'tbody', 'tfoot', 'tr', 'th', 'td', 'pre', 'section', 'img',
+        'figure', 'figcaption', 'span', 'label', 'input', 'details', 'summary', 'address', 'aside', 'footer',
+        'header', 'hgroup', 'main', 'nav', 'dl', 'dt', 'menu', 'bdi', 'bdo', 'dfn', 'kbd', 'mark', 'q', 'time',
+        'var', 'wbr', 'area', 'map', 'track', 'video', 'audio', 'picture', 'del', 'ins',
+        'en-media',
+        'acronym', 'article', 'big', 'button', 'cite', 'col', 'colgroup', 'data', 'dd',
+        'fieldset', 'form', 'legend', 'meter', 'noscript', 'option', 'progress', 'rp',
+        'samp', 'small', 'sub', 'sup', 'template', 'textarea', 'tt'
+    ]), isSynced: true },
 ];
 
 /**