Add option to apply filter actions to existing articles (#7959)

* Add option to apply filter actions to existing articles

* make fix-all

* Fixes

* Another approach with preview
New approach: https://github.com/FreshRSS/FreshRSS/pull/7959/commits/20479475c90ac954b991b3703c3cc76c16aa2d5c

<img width="666" height="202" alt="image" src="https://github.com/user-attachments/assets/bb68ede4-60c8-4e0c-9317-c5ed7a6ad7df" />

Additional improvements:
* Also implemented at category level, and at global level
* Also implemented for favourites at global level

Shortcomings:
* Does not always work reliably with advanced regex, since the DB's flavour is not necessarily the same than PHP's

Related: https://github.com/FreshRSS/FreshRSS/pull/8141

* make fix-all

---------

Co-authored-by: Alexandre Alapetite <alexandre@alapetite.fr>

33 files changed, 114 insertions, 0 deletions

diff --git a/app/Controllers/categoryController.php b/app/Controllers/categoryController.php
index 5ad83e977..2212a158b 100644
--- a/app/Controllers/categoryController.php
+++ b/app/Controllers/categoryController.php
@@ -171,6 +171,30 @@ class FreshRSS_category_Controller extends FreshRSS_ActionController {
 		}
 	}
 
+	public function viewFilterAction(): void {
+		$id = Minz_Request::paramInt('id');
+		if ($id === 0) {
+			Minz_Error::error(400);
+			return;
+		}
+		$filteractions = Minz_Request::paramTextToArray('filteractions_read');
+		$filteractions = array_map(fn(string $action): string => trim($action), $filteractions);
+		$filteractions = array_filter($filteractions, fn(string $action): bool => $action !== '');
+		$search = "c:$id (";
+		foreach ($filteractions as $action) {
+			$search .= "($action) OR ";
+		}
+		$search = preg_replace('/ OR $/', '', $search);
+		$search .= ')';
+		Minz_Request::forward([
+			'c' => 'index',
+			'a' => 'index',
+			'params' => [
+				'search' => $search,
+			],
+		], redirect: true);
+	}
+
 	/**
 	 * This action deletes a category.
 	 * Feeds in the given category are moved in the default category.
diff --git a/app/Controllers/configureController.php b/app/Controllers/configureController.php
index 427fcb584..17c6c20bd 100644
--- a/app/Controllers/configureController.php
+++ b/app/Controllers/configureController.php
@@ -180,6 +180,25 @@ class FreshRSS_configure_Controller extends FreshRSS_ActionController {
 		FreshRSS_View::prependTitle(_t('conf.reading.title') . ' · ');
 	}
 
+	public function viewFilterAction(): void {
+		$search = '';
+		$filters_name = Minz_Request::paramString('filters_name', plaintext: true);
+		$filteractions = Minz_Request::paramTextToArray($filters_name);
+		$filteractions = array_map(fn(string $action): string => trim($action), $filteractions);
+		$filteractions = array_filter($filteractions, fn(string $action): bool => $action !== '');
+		foreach ($filteractions as $action) {
+			$search .= "($action) OR ";
+		}
+		$search = preg_replace('/ OR $/', '', $search);
+		Minz_Request::forward([
+			'c' => 'index',
+			'a' => 'index',
+			'params' => [
+				'search' => $search,
+			],
+		], redirect: true);
+	}
+
 	/**
 	 * This action handles the integration configuration page.
 	 *
diff --git a/app/Controllers/subscriptionController.php b/app/Controllers/subscriptionController.php
index ccd421a41..244a16671 100644
--- a/app/Controllers/subscriptionController.php
+++ b/app/Controllers/subscriptionController.php
@@ -409,6 +409,30 @@ class FreshRSS_subscription_Controller extends FreshRSS_ActionController {
 		}
 	}
 
+	public function viewFilterAction(): void {
+		$id = Minz_Request::paramInt('id');
+		if ($id === 0) {
+			Minz_Error::error(400);
+			return;
+		}
+		$filteractions = Minz_Request::paramTextToArray('filteractions_read');
+		$filteractions = array_map(fn(string $action): string => trim($action), $filteractions);
+		$filteractions = array_filter($filteractions, fn(string $action): bool => $action !== '');
+		$search = "f:$id (";
+		foreach ($filteractions as $action) {
+			$search .= "($action) OR ";
+		}
+		$search = preg_replace('/ OR $/', '', $search);
+		$search .= ')';
+		Minz_Request::forward([
+			'c' => 'index',
+			'a' => 'index',
+			'params' => [
+				'search' => $search,
+			],
+		], redirect: true);
+	}
+
 	/**
 	 * This action displays the bookmarklet page.
 	 */
diff --git a/app/i18n/cs/sub.php b/app/i18n/cs/sub.php
index cbf997322..9c8e16363 100644
--- a/app/i18n/cs/sub.php
+++ b/app/i18n/cs/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Akce filtrování',
 			'help' => 'Zapište jeden filtr hledání na řádek. Operátoři <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">viz dokumentace</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// TODO
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// TODO
diff --git a/app/i18n/de/sub.php b/app/i18n/de/sub.php
index 5fbfdae21..0d6646812 100644
--- a/app/i18n/de/sub.php
+++ b/app/i18n/de/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Filteraktionen',
 			'help' => 'Ein Suchfilter pro Zeile. Operatoren <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">siehe Dokumentation</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// IGNORE
 		'http_headers_help' => 'Headers werden durch einen Zeilenumbruch getrennt. Name und Wert des Headers werden per Doppelpunkt getrennt (z.B: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',
diff --git a/app/i18n/el/sub.php b/app/i18n/el/sub.php
index a9ba689e9..ed6b332ea 100644
--- a/app/i18n/el/sub.php
+++ b/app/i18n/el/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Filter actions',	// TODO
 			'help' => 'Write one search filter per line. Operators <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">see documentation</a>.',	// TODO
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// TODO
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// TODO
diff --git a/app/i18n/en-US/sub.php b/app/i18n/en-US/sub.php
index 8f458095f..5d12dacae 100644
--- a/app/i18n/en-US/sub.php
+++ b/app/i18n/en-US/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Filter actions',	// IGNORE
 			'help' => 'Write one search filter per line. Operators <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">see documentation</a>.',	// IGNORE
+			'view_filter' => 'Preview filters on existing articles (new window)',	// IGNORE
 		),
 		'http_headers' => 'HTTP Headers',	// IGNORE
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// IGNORE
diff --git a/app/i18n/en/sub.php b/app/i18n/en/sub.php
index ee3de4282..7560dc90c 100644
--- a/app/i18n/en/sub.php
+++ b/app/i18n/en/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Filter actions',
 			'help' => 'Write one search filter per line. Operators <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">see documentation</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',
 		),
 		'http_headers' => 'HTTP Headers',
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',
diff --git a/app/i18n/es/sub.php b/app/i18n/es/sub.php
index e5e09d0cc..8b15c4603 100644
--- a/app/i18n/es/sub.php
+++ b/app/i18n/es/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Filtrar acciones',
 			'help' => 'Escribir un filtro de búsqueda por línea. Ver <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">documentación de operadores de búsqueda</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// IGNORE
 		'http_headers_help' => 'Los Headers son separados por un salto de linea, y el nombre y valor de un Header son separados con dos puntos (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',
diff --git a/app/i18n/fa/sub.php b/app/i18n/fa/sub.php
index 239388557..908162473 100644
--- a/app/i18n/fa/sub.php
+++ b/app/i18n/fa/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => ' اعمال فیلتر',
 			'help' => ' در هر خط یک فیلتر جستجو بنویسید. اپراتورها <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">مستندات را ببینید</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP سربرگ‌ها',
 		'http_headers_help' => 'سر برگ ها با یک خط جدید از هم جدا می‌شوند و نام و مقدار سربرگ ها با یک دونقطه از هم جدا می‌شوند (مثلاً: <kbd><code>پذیرش: application/atom+xml<br />مجوز: Bearer some-token</code></kbd>).',
diff --git a/app/i18n/fi/sub.php b/app/i18n/fi/sub.php
index d23943aa8..5d4062135 100644
--- a/app/i18n/fi/sub.php
+++ b/app/i18n/fi/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Suodatustoiminnot',
 			'help' => 'Kirjoita kukin hakusuodatin omalle rivilleen. Lisätietoja operaattoreista <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">ohjeissa</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP-otsikot',
 		'http_headers_help' => 'Otsikot erotellaan rivinvaihdoin, ja nimi ja arvo erotellaan kaksoispisteellä. Esimerkki: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',
diff --git a/app/i18n/fr/sub.php b/app/i18n/fr/sub.php
index 9a0635b62..a52c8f1a1 100644
--- a/app/i18n/fr/sub.php
+++ b/app/i18n/fr/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Filtres d’action',
 			'help' => 'Écrivez une recherche par ligne. Voir la <a href="https://freshrss.github.io/FreshRSS/fr/users/03_Main_view.html#gr%C3%A2ce-au-champ-de-recherche" target="_blank">documentation des opérateurs</a>.',
+			'view_filter' => 'Aperçu des filtres sur les articles existants (nouvelle fenêtre)',
 		),
 		'http_headers' => 'Entêtes HTTP',
 		'http_headers_help' => 'Un entête HTTP par ligne, avec le nom et la valeur séparés par un deux-points (ex. : <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',
diff --git a/app/i18n/he/sub.php b/app/i18n/he/sub.php
index ac45c07c8..5f756bde1 100644
--- a/app/i18n/he/sub.php
+++ b/app/i18n/he/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Filter actions',	// TODO
 			'help' => 'Write one search filter per line. Operators <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">see documentation</a>.',	// TODO
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// TODO
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// TODO
diff --git a/app/i18n/hu/sub.php b/app/i18n/hu/sub.php
index 4c9c60b72..6c3b12e14 100644
--- a/app/i18n/hu/sub.php
+++ b/app/i18n/hu/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Szűrő műveletek',
 			'help' => 'Írj egy szűrőt soronként. Műveletek <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">a dokumentációban</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Fejlécek',
 		'http_headers_help' => 'A fejléceket újsor választja el, a fejléc nevét és értékét kettőspont választja el (pl: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',
diff --git a/app/i18n/id/sub.php b/app/i18n/id/sub.php
index f8578fb61..881e1b01e 100644
--- a/app/i18n/id/sub.php
+++ b/app/i18n/id/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Tindakan penyaringan',
 			'help' => 'Tulis satu penyaringan pencarian per baris. Operator <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">lihat dokumentasi</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'Tajuk HTTP',
 		'http_headers_help' => 'Tajuk dipisahkan dengan baris baru dan nama dan nilai dari tajuk dipisahkan dengan titik dua (contoh: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',
diff --git a/app/i18n/it/sub.php b/app/i18n/it/sub.php
index 5d381a3dc..48beb21db 100644
--- a/app/i18n/it/sub.php
+++ b/app/i18n/it/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Azioni di filtro',
 			'help' => 'Scrivi un filtro di ricerca per riga. Per li operatori <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">vedi la documentazione</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// IGNORE
 		'http_headers_help' => 'Le intestazioni sono separate da una linea e il nome e il valore di un’intestazione sono separati da due punti (p.es: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',
diff --git a/app/i18n/ja/sub.php b/app/i18n/ja/sub.php
index d02117031..1d1e8c4ce 100644
--- a/app/i18n/ja/sub.php
+++ b/app/i18n/ja/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'フィルターアクション',
 			'help' => '1行に1つの検索フィルターを設定してください。演算子は<a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">ドキュメントを参照してください</a>。',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTPヘッダ',
 		'http_headers_help' => 'ヘッダは改行で区切られ、ヘッダの名前と値はコロンで区切られます (例: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',
diff --git a/app/i18n/ko/sub.php b/app/i18n/ko/sub.php
index 8719e6f7b..9a9e15776 100644
--- a/app/i18n/ko/sub.php
+++ b/app/i18n/ko/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => '필터 동작',
 			'help' => '한 줄에 한 검색 필터를 작성해 주세요. 실행시 <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">문서 참고</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// TODO
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// TODO
diff --git a/app/i18n/lv/sub.php b/app/i18n/lv/sub.php
index 337d9418d..ddbcd9e8c 100644
--- a/app/i18n/lv/sub.php
+++ b/app/i18n/lv/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Filtra darbības',
 			'help' => 'Uzrakstiet vienu meklēšanas filtru katrā rindā. Operators <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">see documentation</a>.',	// DIRTY
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// TODO
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// TODO
diff --git a/app/i18n/nl/sub.php b/app/i18n/nl/sub.php
index 02aec863c..353c89fcb 100644
--- a/app/i18n/nl/sub.php
+++ b/app/i18n/nl/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Filteracties',
 			'help' => 'Voer één zoekfilter per lijn in. Operators <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">see documentation</a>.',	// DIRTY
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP-headers',
 		'http_headers_help' => 'Headers worden gescheiden door een regeleinde, en de naam en waarde van een header worden gescheiden door een dubbele punt (bijv.: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer een-token</code></kbd>).',
diff --git a/app/i18n/oc/sub.php b/app/i18n/oc/sub.php
index 678b32e1d..08510b9cb 100644
--- a/app/i18n/oc/sub.php
+++ b/app/i18n/oc/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Filtre d’accion',
 			'help' => 'Escrivètz una recèrca per linha. Operators <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">see documentation</a>.',	// DIRTY
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// TODO
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// TODO
diff --git a/app/i18n/pl/sub.php b/app/i18n/pl/sub.php
index a968b975b..55c24ab26 100644
--- a/app/i18n/pl/sub.php
+++ b/app/i18n/pl/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Akcje filtrowania',
 			'help' => 'Jedno zapytanie na linię. Operatory opisane są w <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">dokumentacji</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'Nagłówki HTTP',
 		'http_headers_help' => 'Nagłówki są oddzielane przez nową linię, a nazwa i wartość nagłówka są oddzielane przez dwukropek (np: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer jakiś-token</code></kbd>).',
diff --git a/app/i18n/pt-BR/sub.php b/app/i18n/pt-BR/sub.php
index 06703a6a2..0d43e6c93 100644
--- a/app/i18n/pt-BR/sub.php
+++ b/app/i18n/pt-BR/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Ações do filtro',
 			'help' => 'Escreva um filtro de pesquisa por linha. Operators <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">see documentation</a>.',	// DIRTY
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// TODO
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// TODO
diff --git a/app/i18n/pt-PT/sub.php b/app/i18n/pt-PT/sub.php
index 72582fe25..0d2248cd1 100644
--- a/app/i18n/pt-PT/sub.php
+++ b/app/i18n/pt-PT/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Ações do filtro',
 			'help' => 'Escreva um filtro de pesquisa por linha. <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">Ver documentação</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// TODO
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// TODO
diff --git a/app/i18n/ru/sub.php b/app/i18n/ru/sub.php
index 174b80ce2..3abf60146 100644
--- a/app/i18n/ru/sub.php
+++ b/app/i18n/ru/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Действия фильтрации',
 			'help' => 'Введите по одному поисковому фильтру в строке. См. <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">документацию</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// TODO
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// TODO
diff --git a/app/i18n/sk/sub.php b/app/i18n/sk/sub.php
index a8026ee0f..42fa17ab4 100644
--- a/app/i18n/sk/sub.php
+++ b/app/i18n/sk/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Filtrovať akcie',
 			'help' => 'Napíšte jeden výraz hľadania na riadok. Operators <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">see documentation</a>.',	// DIRTY
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// TODO
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// TODO
diff --git a/app/i18n/tr/sub.php b/app/i18n/tr/sub.php
index 62a0c43f4..bb2219e16 100644
--- a/app/i18n/tr/sub.php
+++ b/app/i18n/tr/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Filtre eylemleri',
 			'help' => 'Her satıra bir arama filtresi yazın. Operatörler için <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">belgelere bakın</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Başlıkları',
 		'http_headers_help' => 'Başlıklar yeni bir satırla ayrılır ve bir başlığın adı ile değeri iki nokta üst üste ile ayrılır (örneğin: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',
diff --git a/app/i18n/uk/sub.php b/app/i18n/uk/sub.php
index 547593a92..8cc8b69ce 100644
--- a/app/i18n/uk/sub.php
+++ b/app/i18n/uk/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => 'Автоматичний фільтр',
 			'help' => 'По одному фільтру на рядок. Перегляньте <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">документацію операторів</a>.',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP-заголовки',
 		'http_headers_help' => 'По заголовку на рядок. Назву й значення відокремлено двокрапкою (наприклад, <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer деякий-токен</code></kbd>).',
diff --git a/app/i18n/zh-CN/sub.php b/app/i18n/zh-CN/sub.php
index 65b633107..0b0389c8e 100644
--- a/app/i18n/zh-CN/sub.php
+++ b/app/i18n/zh-CN/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => '过滤动作',
 			'help' => '每行写一条过滤规则，过滤规则可见 <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">文档</a>。',
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// TODO
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// TODO
diff --git a/app/i18n/zh-TW/sub.php b/app/i18n/zh-TW/sub.php
index 06ef379f2..3b6ff614b 100644
--- a/app/i18n/zh-TW/sub.php
+++ b/app/i18n/zh-TW/sub.php
@@ -80,6 +80,7 @@ return array(
 		'filteractions' => array(
 			'_' => '過濾動作',
 			'help' => '每行寫一條過濾搜尋 Operators <a href="https://freshrss.github.io/FreshRSS/en/users/10_filter.html#with-the-search-field" target="_blank">see documentation</a>.',	// DIRTY
+			'view_filter' => 'Preview filters on existing articles (new window)',	// TODO
 		),
 		'http_headers' => 'HTTP Headers',	// TODO
 		'http_headers_help' => 'Headers are separated by a newline, and the name and value of a header are separated by a colon (e.g: <kbd><code>Accept: application/atom+xml<br />Authorization: Bearer some-token</code></kbd>).',	// TODO
diff --git a/app/views/configure/reading.phtml b/app/views/configure/reading.phtml
index e9a21839c..3b92a9e4f 100644
--- a/app/views/configure/reading.phtml
+++ b/app/views/configure/reading.phtml
@@ -353,6 +353,11 @@
 						}
 					?></textarea>
 					<p class="help"><?= _i('help') ?> <?= _t('sub.feed.filteractions.help') ?></p>
+					<p>
+						<button class="btn" formaction="<?= _url('configure', 'viewFilter', 'filters_name', 'filteractions_read') ?>" formtarget="_blank">
+							<?= _t('sub.feed.filteractions.view_filter') ?>
+						</button>
+					</p>
 				</div>
 			</div>
 
@@ -365,6 +370,11 @@
 						}
 					?></textarea>
 					<p class="help"><?= _i('help') ?> <?= _t('sub.feed.filteractions.help') ?></p>
+					<p>
+						<button class="btn" formaction="<?= _url('configure', 'viewFilter', 'filters_name', 'filteractions_star') ?>" formtarget="_blank">
+							<?= _t('sub.feed.filteractions.view_filter') ?>
+						</button>
+					</p>
 				</div>
 			</div>
 
diff --git a/app/views/helpers/category/update.phtml b/app/views/helpers/category/update.phtml
index 5e5fb4f10..231f86ebd 100644
--- a/app/views/helpers/category/update.phtml
+++ b/app/views/helpers/category/update.phtml
@@ -100,6 +100,11 @@
 						}
 					?></textarea>
 					<p class="help"><?= _i('help') ?> <?= _t('sub.feed.filteractions.help') ?></p>
+					<p>
+						<button class="btn" formaction="<?= _url('category', 'viewFilter', 'id', $this->category->id()); ?>" formtarget="_blank">
+							<?= _t('sub.feed.filteractions.view_filter') ?>
+						</button>
+					</p>
 				</div>
 			</div>
 
diff --git a/app/views/helpers/feed/update.phtml b/app/views/helpers/feed/update.phtml
index c5dae8460..301cb1ced 100644
--- a/app/views/helpers/feed/update.phtml
+++ b/app/views/helpers/feed/update.phtml
@@ -308,6 +308,11 @@
 						}
 					?></textarea>
 					<p class="help"><?= _i('help') ?> <?= _t('sub.feed.filteractions.help') ?></p>
+					<p>
+						<button class="btn" formaction="<?= _url('subscription', 'viewFilter', 'id', $this->feed->id()); ?>" formtarget="_blank">
+							<?= _t('sub.feed.filteractions.view_filter') ?>
+						</button>
+					</p>
 				</div>
 			</div>