AnkiUtil (#1439)

* Add AnkiUtil

* Update AnkiConnect to use AnkiUtil

* Use AnkiUtil in AnkiNoteBuilder

* Replace containsAnyMarker with AnkiUtil.stringContainsAnyFieldMarker

* Add AnkiUtil.getFieldMarkers

* Add fieldsObjectContainsMarker to AnkiUtil

* Remove unused global

* Remove unused parameter: enabled

* Add cloneFieldMarkerPattern

3 files changed, 98 insertions, 40 deletions

diff --git a/ext/js/data/anki-note-builder.js b/ext/js/data/anki-note-builder.js
index e1399f66..f12846b1 100644
--- a/ext/js/data/anki-note-builder.js
+++ b/ext/js/data/anki-note-builder.js
@@ -16,13 +16,14 @@
  */
 
 /* global
+ * AnkiUtil
  * TemplateRendererProxy
  */
 
 class AnkiNoteBuilder {
-    constructor(enabled) {
-        this._markerPattern = /\{([\w-]+)\}/g;
-        this._templateRenderer = enabled ? new TemplateRendererProxy() : null;
+    constructor() {
+        this._markerPattern = AnkiUtil.cloneFieldMarkerPattern(true);
+        this._templateRenderer = new TemplateRendererProxy();
     }
 
     async createNote({
@@ -46,7 +47,7 @@ class AnkiNoteBuilder {
         let duplicateScopeCheckChildren = false;
         if (duplicateScope === 'deck-root') {
             duplicateScope = 'deck';
-            duplicateScopeDeckName = this.getRootDeckName(deckName);
+            duplicateScopeDeckName = AnkiUtil.getRootDeckName(deckName);
             duplicateScopeCheckChildren = true;
         }
 
@@ -89,27 +90,6 @@ class AnkiNoteBuilder {
         };
     }
 
-    containsMarker(fields, marker) {
-        marker = `{${marker}}`;
-        for (const [, fieldValue] of fields) {
-            if (fieldValue.includes(marker)) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    containsAnyMarker(field) {
-        const result = this._markerPattern.test(field);
-        this._markerPattern.lastIndex = 0;
-        return result;
-    }
-
-    getRootDeckName(deckName) {
-        const index = deckName.indexOf('::');
-        return index >= 0 ? deckName.substring(0, index) : deckName;
-    }
-
     // Private
 
     async _formatField(field, data, templates, errors=null) {
diff --git a/ext/js/data/anki-util.js b/ext/js/data/anki-util.js
new file mode 100644
index 00000000..fc081ddc
--- /dev/null
+++ b/ext/js/data/anki-util.js
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2021  Yomichan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ * This class has some general utility functions for working with Anki data.
+ */
+class AnkiUtil {
+    /**
+     * Gets the root deck name of a full deck name. If the deck is a root deck,
+     * the same name is returned. Nested decks are separated using '::'.
+     * @param deckName A string of the deck name.
+     * @returns A string corresponding to the name of the root deck.
+     */
+    static getRootDeckName(deckName) {
+        const index = deckName.indexOf('::');
+        return index >= 0 ? deckName.substring(0, index) : deckName;
+    }
+
+    /**
+     * Checks whether or not any marker is contained in a string.
+     * @param string A string to check.
+     * @return `true` if the text contains an Anki field marker, `false` otherwise.
+     */
+    static stringContainsAnyFieldMarker(string) {
+        const result = this._markerPattern.test(string);
+        this._markerPattern.lastIndex = 0;
+        return result;
+    }
+
+    /**
+     * Gets a list of all markers that are contained in a string.
+     * @param string A string to check.
+     * @return An array of marker strings.
+     */
+    static getFieldMarkers(string) {
+        const pattern = this._markerPattern;
+        const markers = [];
+        while (true) {
+            const match = pattern.exec(string);
+            if (match === null) { break; }
+            markers.push(match[1]);
+        }
+        return markers;
+    }
+
+    /**
+     * Checks whether an object of key-value pairs has a value which contains a specific marker.
+     * @param fieldsObject An object with key-value pairs, where the value corresponds to the field value.
+     * @param marker The marker string to check for, excluding brackets.
+     * @returns `true` if any of the fields contains the marker, `false` otherwise.
+     */
+    static fieldsObjectContainsMarker(fieldsObject, marker) {
+        marker = `{${marker}}`;
+        for (const [, fieldValue] of fieldsObject) {
+            if (fieldValue.includes(marker)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Returns a regular expression which can be used to find markers in a string.
+     * @param global Whether or not the regular expression should have the global flag.
+     * @returns A new `RegExp` instance.
+     */
+    static cloneFieldMarkerPattern(global) {
+        return new RegExp(this._markerPattern.source, global ? 'g' : '');
+    }
+}
+
+// eslint-disable-next-line no-underscore-dangle
+AnkiUtil._markerPattern = /\{([\w-]+)\}/g;
diff --git a/ext/js/data/permissions-util.js b/ext/js/data/permissions-util.js
index bd3a18ce..3a5b5de5 100644
--- a/ext/js/data/permissions-util.js
+++ b/ext/js/data/permissions-util.js
@@ -15,13 +15,16 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+/* global
+ * AnkiUtil
+ */
+
 class PermissionsUtil {
     constructor() {
         this._ankiFieldMarkersRequiringClipboardPermission = new Set([
             'clipboard-image',
             'clipboard-text'
         ]);
-        this._ankiMarkerPattern = /\{([\w-]+)\}/g;
     }
 
     hasPermissions(permissions) {
@@ -69,7 +72,7 @@ class PermissionsUtil {
     }
 
     getRequiredPermissionsForAnkiFieldValue(fieldValue) {
-        const markers = this._getAnkiFieldMarkers(fieldValue);
+        const markers = AnkiUtil.getFieldMarkers(fieldValue);
         const markerPermissions = this._ankiFieldMarkersRequiringClipboardPermission;
         for (const marker of markers) {
             if (markerPermissions.has(marker)) {
@@ -99,7 +102,7 @@ class PermissionsUtil {
             ];
             for (const fields of fieldsList) {
                 for (const fieldValue of Object.values(fields)) {
-                    const markers = this._getAnkiFieldMarkers(fieldValue);
+                    const markers = AnkiUtil.getFieldMarkers(fieldValue);
                     for (const marker of markers) {
                         if (fieldMarkersRequiringClipboardPermission.has(marker)) {
                             return false;
@@ -111,16 +114,4 @@ class PermissionsUtil {
 
         return true;
     }
-
-    // Private
-
-    _getAnkiFieldMarkers(fieldValue) {
-        const pattern = this._ankiMarkerPattern;
-        const markers = [];
-        let match;
-        while ((match = pattern.exec(fieldValue)) !== null) {
-            markers.push(match[1]);
-        }
-        return markers;
-    }
 }