From 2a18c826a314e1a03073a0f72991d035e357a124 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Fri, 2 May 2025 19:04:39 +0200
Subject: [PATCH 01/10] feat: enhance category selection and filtering with
 multiple selection

---
 .../website/listing/quarto-listing.js         | 126 +++++++++++++-----
 1 file changed, 93 insertions(+), 33 deletions(-)

diff --git a/src/resources/projects/website/listing/quarto-listing.js b/src/resources/projects/website/listing/quarto-listing.js
index e9a07b2ea39..5dd8b77e3bc 100644
--- a/src/resources/projects/website/listing/quarto-listing.js
+++ b/src/resources/projects/website/listing/quarto-listing.js
@@ -1,12 +1,14 @@
 const kProgressiveAttr = "data-src";
 let categoriesLoaded = false;
+let selectedCategories = new Set();
+const kDefaultCategory = ""; // Default category "" means all posts selected
 
 window.quartoListingCategory = (category) => {
   // category is URI encoded in EJS template for UTF-8 support
   category = decodeURIComponent(atob(category));
   if (categoriesLoaded) {
     activateCategory(category);
-    setCategoryHash(category);
+    setCategoryHash();
   }
 };
 
@@ -15,11 +17,19 @@ window["quarto-listing-loaded"] = () => {
   const hash = getHash();
 
   if (hash) {
-    // If there is a category, switch to that
-    if (hash.category) {
-      // category hash are URI encoded so we need to decode it before processing
-      // so that we can match it with the category element processed in JS
-      activateCategory(decodeURIComponent(hash.category));
+    // If there are categories, switch to those
+    if (hash.categories) {
+      const cats = hash.categories.split(",");
+      for (const cat of cats) {
+        if (cat) selectedCategories.add(decodeURIComponent(cat));
+      }
+      updateCategoryUI();
+      filterListingCategories();
+    } else {
+      // No categories in hash, use default
+      selectedCategories.add(kDefaultCategory);
+      updateCategoryUI();
+      filterListingCategories();
     }
     // Paginate a specific listing
     const listingIds = Object.keys(window["quarto-listings"]);
@@ -29,6 +39,11 @@ window["quarto-listing-loaded"] = () => {
         showPage(listingId, page);
       }
     }
+  } else {
+    // No hash at all, use default category
+    selectedCategories.add(kDefaultCategory);
+    updateCategoryUI();
+    filterListingCategories();
   }
 
   const listingIds = Object.keys(window["quarto-listings"]);
@@ -66,9 +81,14 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
     const category = decodeURIComponent(
       atob(categoryEl.getAttribute("data-category"))
     );
-    categoryEl.onclick = () => {
+    categoryEl.onclick = (e) => {
+      // Allow holding Ctrl/Cmd key for multiple selection
+      // Clear other selections if not using Ctrl/Cmd
+      if (!e.ctrlKey && !e.metaKey) {
+        selectedCategories.clear();
+      }
       activateCategory(category);
-      setCategoryHash(category);
+      setCategoryHash();
     };
   }
 
@@ -79,11 +99,29 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
   );
   for (const categoryTitleEl of categoryTitleEls) {
     categoryTitleEl.onclick = () => {
-      activateCategory("");
-      setCategoryHash("");
+      selectedCategories.clear();
+      updateCategoryUI();
+      setCategoryHash();
+      filterListingCategories();
     };
   }
 
+  // Process any existing hash for multiple categories
+  const hash = getHash();
+  if (hash && hash.categories) {
+    const cats = hash.categories.split(",");
+    for (const cat of cats) {
+      if (cat) selectedCategories.add(decodeURIComponent(cat));
+    }
+    updateCategoryUI();
+    filterListingCategories();
+  } else {
+    // No hash at all, use default category
+    selectedCategories.add(kDefaultCategory);
+    updateCategoryUI();
+    filterListingCategories();
+  }
+
   categoriesLoaded = true;
 });
 
@@ -101,8 +139,15 @@ function toggleNoMatchingMessage(list) {
   }
 }
 
-function setCategoryHash(category) {
-  setHash({ category });
+function setCategoryHash() {
+  if (selectedCategories.size === 0) {
+    setHash({});
+  } else {
+    const categoriesStr = Array.from(selectedCategories)
+      .map((cat) => encodeURIComponent(cat))
+      .join(",");
+    setHash({ category: categoriesStr });
+  }
 }
 
 function setPageHash(listingId, page) {
@@ -205,45 +250,60 @@ function showPage(listingId, page) {
 }
 
 function activateCategory(category) {
-  // Deactivate existing categories
-  const activeEls = window.document.querySelectorAll(
-    ".quarto-listing-category .category.active"
-  );
-  for (const activeEl of activeEls) {
-    activeEl.classList.remove("active");
+  if (selectedCategories.has(category)) {
+    selectedCategories.delete(category);
+  } else {
+    selectedCategories.add(category);
   }
+  updateCategoryUI();
+  filterListingCategories();
+}
 
-  // Activate this category
-  const categoryEl = window.document.querySelector(
-    `.quarto-listing-category .category[data-category='${btoa(
-      encodeURIComponent(category)
-    )}']`
+function updateCategoryUI() {
+  // Deactivate all categories first
+  const activeEls = window.document.querySelectorAll(
+    ".quarto-listing-category .category"
   );
-  if (categoryEl) {
-    categoryEl.classList.add("active");
+  for (const activeEls of activeEls) {
+    activeEls.classList.remove("active");
   }
 
-  // Filter the listings to this category
-  filterListingCategory(category);
+  // Activate selected categories
+  for (const category of selectedCategories) {
+    const categoryEl = window.document.querySelector(
+      `.quarto-listing-category .category[data-category='${btoa(
+        encodeURIComponent(category)
+      )}']`
+    );
+    if (categoryEl) {
+      categoryEl.classList.add("active");
+    }
+  }
 }
 
-function filterListingCategory(category) {
+function filterListingCategories() {
   const listingIds = Object.keys(window["quarto-listings"]);
   for (const listingId of listingIds) {
     const list = window["quarto-listings"][listingId];
     if (list) {
-      if (category === "") {
-        // resets the filter
+      if (selectedCategories.size === 0 ||
+        (selectedCategories.size === 1 && selectedCategories.has(kDefaultCategory))) {
+        // Reset the filter when no categories selected or only default category
         list.filter();
       } else {
-        // filter to this category
+        // Filter to selected categories, but ignore kDefaultCategory if other categories selected
+        const effectiveCategories = new Set(selectedCategories);
+        if (effectiveCategories.size > 1) {
+          effectiveCategories.delete(kDefaultCategory);
+        }
+
         list.filter(function (item) {
           const itemValues = item.values();
           if (itemValues.categories !== null) {
-            const categories = decodeURIComponent(
+            const itemCategories = decodeURIComponent(
               atob(itemValues.categories)
             ).split(",");
-            return categories.includes(category);
+            return itemCategories.some(category => effectiveCategories.has(category));
           } else {
             return false;
           }

From 08d00e068ed7f3faf445cd5939a8eba70fa37922 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Fri, 2 May 2025 19:20:24 +0200
Subject: [PATCH 02/10] revert: keep original names

---
 .../website/listing/quarto-listing.js         | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/resources/projects/website/listing/quarto-listing.js b/src/resources/projects/website/listing/quarto-listing.js
index 5dd8b77e3bc..4ce84abe0fe 100644
--- a/src/resources/projects/website/listing/quarto-listing.js
+++ b/src/resources/projects/website/listing/quarto-listing.js
@@ -24,12 +24,12 @@ window["quarto-listing-loaded"] = () => {
         if (cat) selectedCategories.add(decodeURIComponent(cat));
       }
       updateCategoryUI();
-      filterListingCategories();
+      filterListingCategory();
     } else {
       // No categories in hash, use default
       selectedCategories.add(kDefaultCategory);
       updateCategoryUI();
-      filterListingCategories();
+      filterListingCategory();
     }
     // Paginate a specific listing
     const listingIds = Object.keys(window["quarto-listings"]);
@@ -43,7 +43,7 @@ window["quarto-listing-loaded"] = () => {
     // No hash at all, use default category
     selectedCategories.add(kDefaultCategory);
     updateCategoryUI();
-    filterListingCategories();
+    filterListingCategory();
   }
 
   const listingIds = Object.keys(window["quarto-listings"]);
@@ -102,7 +102,7 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
       selectedCategories.clear();
       updateCategoryUI();
       setCategoryHash();
-      filterListingCategories();
+      filterListingCategory();
     };
   }
 
@@ -114,12 +114,12 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
       if (cat) selectedCategories.add(decodeURIComponent(cat));
     }
     updateCategoryUI();
-    filterListingCategories();
+    filterListingCategory();
   } else {
     // No hash at all, use default category
     selectedCategories.add(kDefaultCategory);
     updateCategoryUI();
-    filterListingCategories();
+    filterListingCategory();
   }
 
   categoriesLoaded = true;
@@ -256,7 +256,7 @@ function activateCategory(category) {
     selectedCategories.add(category);
   }
   updateCategoryUI();
-  filterListingCategories();
+  filterListingCategory();
 }
 
 function updateCategoryUI() {
@@ -281,7 +281,7 @@ function updateCategoryUI() {
   }
 }
 
-function filterListingCategories() {
+function filterListingCategory() {
   const listingIds = Object.keys(window["quarto-listings"]);
   for (const listingId of listingIds) {
     const list = window["quarto-listings"][listingId];
@@ -300,10 +300,10 @@ function filterListingCategories() {
         list.filter(function (item) {
           const itemValues = item.values();
           if (itemValues.categories !== null) {
-            const itemCategories = decodeURIComponent(
+            const categories = decodeURIComponent(
               atob(itemValues.categories)
             ).split(",");
-            return itemCategories.some(category => effectiveCategories.has(category));
+            return categories.some(category => effectiveCategories.has(category));
           } else {
             return false;
           }

From 87248446a6236696b488eb25b9a328e9f42a35a5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Fri, 2 May 2025 19:54:09 +0200
Subject: [PATCH 03/10] fix: logic for default category and keep "category" as
 URL hash key

---
 .../website/listing/quarto-listing.js         | 22 ++++++++++++-------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/resources/projects/website/listing/quarto-listing.js b/src/resources/projects/website/listing/quarto-listing.js
index 4ce84abe0fe..1c7f34071c7 100644
--- a/src/resources/projects/website/listing/quarto-listing.js
+++ b/src/resources/projects/website/listing/quarto-listing.js
@@ -18,8 +18,8 @@ window["quarto-listing-loaded"] = () => {
 
   if (hash) {
     // If there are categories, switch to those
-    if (hash.categories) {
-      const cats = hash.categories.split(",");
+    if (hash.category) {
+      const cats = hash.category.split(",");
       for (const cat of cats) {
         if (cat) selectedCategories.add(decodeURIComponent(cat));
       }
@@ -87,6 +87,12 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
       if (!e.ctrlKey && !e.metaKey) {
         selectedCategories.clear();
       }
+
+      // If this would deselect the last category, ensure default category remains selected
+      if (selectedCategories.has(category) && selectedCategories.size === 1) {
+        selectedCategories.add(kDefaultCategory);
+      }
+
       activateCategory(category);
       setCategoryHash();
     };
@@ -108,8 +114,8 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
 
   // Process any existing hash for multiple categories
   const hash = getHash();
-  if (hash && hash.categories) {
-    const cats = hash.categories.split(",");
+  if (hash && hash.category) {
+    const cats = hash.category.split(",");
     for (const cat of cats) {
       if (cat) selectedCategories.add(decodeURIComponent(cat));
     }
@@ -261,11 +267,11 @@ function activateCategory(category) {
 
 function updateCategoryUI() {
   // Deactivate all categories first
-  const activeEls = window.document.querySelectorAll(
+  const categoryEls = window.document.querySelectorAll(
     ".quarto-listing-category .category"
   );
-  for (const activeEls of activeEls) {
-    activeEls.classList.remove("active");
+  for (const categoryEl of categoryEls) {
+    categoryEl.classList.remove("active");
   }
 
   // Activate selected categories
@@ -293,7 +299,7 @@ function filterListingCategory() {
       } else {
         // Filter to selected categories, but ignore kDefaultCategory if other categories selected
         const effectiveCategories = new Set(selectedCategories);
-        if (effectiveCategories.size > 1) {
+        if (effectiveCategories.size > 1 && effectiveCategories.has(kDefaultCategory)) {
           effectiveCategories.delete(kDefaultCategory);
         }
 

From 94fbe36bf36fb7f5823d4fd10c902c845225e66a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Fri, 2 May 2025 20:32:47 +0200
Subject: [PATCH 04/10] fix: clear and add post category to hash

---
 src/resources/projects/website/listing/quarto-listing.js | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/resources/projects/website/listing/quarto-listing.js b/src/resources/projects/website/listing/quarto-listing.js
index 1c7f34071c7..ca06d55a54b 100644
--- a/src/resources/projects/website/listing/quarto-listing.js
+++ b/src/resources/projects/website/listing/quarto-listing.js
@@ -6,10 +6,11 @@ const kDefaultCategory = ""; // Default category "" means all posts selected
 window.quartoListingCategory = (category) => {
   // category is URI encoded in EJS template for UTF-8 support
   category = decodeURIComponent(atob(category));
-  if (categoriesLoaded) {
-    activateCategory(category);
-    setCategoryHash();
-  }
+  selectedCategories.clear();
+  selectedCategories.add(category);
+  updateCategoryUI();
+  filterListingCategory();
+  setCategoryHash();
 };
 
 window["quarto-listing-loaded"] = () => {

From a42adc83164339a741b021ad429ddd86aa73f3d5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Wed, 7 May 2025 21:18:20 +0200
Subject: [PATCH 05/10] refactor: improve logic and dry code a bit

---
 .../website/listing/quarto-listing.js         | 40 ++++++++-----------
 1 file changed, 17 insertions(+), 23 deletions(-)

diff --git a/src/resources/projects/website/listing/quarto-listing.js b/src/resources/projects/website/listing/quarto-listing.js
index ca06d55a54b..c46a4b1c13d 100644
--- a/src/resources/projects/website/listing/quarto-listing.js
+++ b/src/resources/projects/website/listing/quarto-listing.js
@@ -8,9 +8,9 @@ window.quartoListingCategory = (category) => {
   category = decodeURIComponent(atob(category));
   selectedCategories.clear();
   selectedCategories.add(category);
-  updateCategoryUI();
-  filterListingCategory();
+
   setCategoryHash();
+  updateCategory();
 };
 
 window["quarto-listing-loaded"] = () => {
@@ -24,13 +24,11 @@ window["quarto-listing-loaded"] = () => {
       for (const cat of cats) {
         if (cat) selectedCategories.add(decodeURIComponent(cat));
       }
-      updateCategoryUI();
-      filterListingCategory();
+      updateCategory();
     } else {
       // No categories in hash, use default
       selectedCategories.add(kDefaultCategory);
-      updateCategoryUI();
-      filterListingCategory();
+      updateCategory();
     }
     // Paginate a specific listing
     const listingIds = Object.keys(window["quarto-listings"]);
@@ -43,8 +41,7 @@ window["quarto-listing-loaded"] = () => {
   } else {
     // No hash at all, use default category
     selectedCategories.add(kDefaultCategory);
-    updateCategoryUI();
-    filterListingCategory();
+    updateCategory();
   }
 
   const listingIds = Object.keys(window["quarto-listings"]);
@@ -90,12 +87,17 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
       }
 
       // If this would deselect the last category, ensure default category remains selected
-      if (selectedCategories.has(category) && selectedCategories.size === 1) {
-        selectedCategories.add(kDefaultCategory);
+      if (selectedCategories.has(category)) {
+        selectedCategories.delete(category);
+        if (selectedCategories.size === 1) {
+          selectedCategories.add(kDefaultCategory);
+        }
+      } else {
+        selectedCategories.add(category);
       }
 
-      activateCategory(category);
       setCategoryHash();
+      updateCategory();
     };
   }
 
@@ -107,9 +109,8 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
   for (const categoryTitleEl of categoryTitleEls) {
     categoryTitleEl.onclick = () => {
       selectedCategories.clear();
-      updateCategoryUI();
       setCategoryHash();
-      filterListingCategory();
+      updateCategory();
     };
   }
 
@@ -120,13 +121,11 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
     for (const cat of cats) {
       if (cat) selectedCategories.add(decodeURIComponent(cat));
     }
-    updateCategoryUI();
-    filterListingCategory();
+    updateCategory();
   } else {
     // No hash at all, use default category
     selectedCategories.add(kDefaultCategory);
-    updateCategoryUI();
-    filterListingCategory();
+    updateCategory();
   }
 
   categoriesLoaded = true;
@@ -256,12 +255,7 @@ function showPage(listingId, page) {
   }
 }
 
-function activateCategory(category) {
-  if (selectedCategories.has(category)) {
-    selectedCategories.delete(category);
-  } else {
-    selectedCategories.add(category);
-  }
+function updateCategory() {
   updateCategoryUI();
   filterListingCategory();
 }

From 150bee68d6b295899737dcc51e84f7cd45d2b39d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Wed, 7 May 2025 21:19:50 +0200
Subject: [PATCH 06/10] refactor: hash after update

---
 src/resources/projects/website/listing/quarto-listing.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/resources/projects/website/listing/quarto-listing.js b/src/resources/projects/website/listing/quarto-listing.js
index c46a4b1c13d..ebd71fb6610 100644
--- a/src/resources/projects/website/listing/quarto-listing.js
+++ b/src/resources/projects/website/listing/quarto-listing.js
@@ -9,8 +9,8 @@ window.quartoListingCategory = (category) => {
   selectedCategories.clear();
   selectedCategories.add(category);
 
-  setCategoryHash();
   updateCategory();
+  setCategoryHash();
 };
 
 window["quarto-listing-loaded"] = () => {
@@ -96,8 +96,8 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
         selectedCategories.add(category);
       }
 
-      setCategoryHash();
       updateCategory();
+      setCategoryHash();
     };
   }
 
@@ -109,8 +109,8 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
   for (const categoryTitleEl of categoryTitleEls) {
     categoryTitleEl.onclick = () => {
       selectedCategories.clear();
-      setCategoryHash();
       updateCategory();
+      setCategoryHash();
     };
   }
 

From 0cb3c76cc689b0d4c519b393efc9dc31c7c9a7c4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Thu, 8 May 2025 11:28:15 +0200
Subject: [PATCH 07/10] chore: remove no longer used variable

---
 src/resources/projects/website/listing/quarto-listing.js | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/src/resources/projects/website/listing/quarto-listing.js b/src/resources/projects/website/listing/quarto-listing.js
index ebd71fb6610..5c826814d57 100644
--- a/src/resources/projects/website/listing/quarto-listing.js
+++ b/src/resources/projects/website/listing/quarto-listing.js
@@ -1,5 +1,4 @@
 const kProgressiveAttr = "data-src";
-let categoriesLoaded = false;
 let selectedCategories = new Set();
 const kDefaultCategory = ""; // Default category "" means all posts selected
 
@@ -127,8 +126,6 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
     selectedCategories.add(kDefaultCategory);
     updateCategory();
   }
-
-  categoriesLoaded = true;
 });
 
 function toggleNoMatchingMessage(list) {

From 8741974df54a86ec83bf26e6d303606823b7af39 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Wed, 14 Jan 2026 23:54:59 +0100
Subject: [PATCH 08/10] fix: remove duplicate hash parsing

quarto-listing-loaded already handles this.
---
 .../website/listing/quarto-listing.js         | 20 +++----------------
 1 file changed, 3 insertions(+), 17 deletions(-)

diff --git a/src/resources/projects/website/listing/quarto-listing.js b/src/resources/projects/website/listing/quarto-listing.js
index 5c826814d57..7e16de0b93b 100644
--- a/src/resources/projects/website/listing/quarto-listing.js
+++ b/src/resources/projects/website/listing/quarto-listing.js
@@ -79,8 +79,8 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
       atob(categoryEl.getAttribute("data-category"))
     );
     categoryEl.onclick = (e) => {
-      // Allow holding Ctrl/Cmd key for multiple selection
-      // Clear other selections if not using Ctrl/Cmd
+      // Allow holding Ctrl (Windows/Linux) or Cmd (macOS) for multiple selection
+      // Clear other selections if not using modifier key
       if (!e.ctrlKey && !e.metaKey) {
         selectedCategories.clear();
       }
@@ -88,7 +88,7 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
       // If this would deselect the last category, ensure default category remains selected
       if (selectedCategories.has(category)) {
         selectedCategories.delete(category);
-        if (selectedCategories.size === 1) {
+        if (selectedCategories.size === 0) {
           selectedCategories.add(kDefaultCategory);
         }
       } else {
@@ -112,20 +112,6 @@ window.document.addEventListener("DOMContentLoaded", function (_event) {
       setCategoryHash();
     };
   }
-
-  // Process any existing hash for multiple categories
-  const hash = getHash();
-  if (hash && hash.category) {
-    const cats = hash.category.split(",");
-    for (const cat of cats) {
-      if (cat) selectedCategories.add(decodeURIComponent(cat));
-    }
-    updateCategory();
-  } else {
-    // No hash at all, use default category
-    selectedCategories.add(kDefaultCategory);
-    updateCategory();
-  }
 });
 
 function toggleNoMatchingMessage(list) {

From daa36c8f23f0c1d44b7e51e5d8a76933195d7084 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Wed, 14 Jan 2026 23:55:20 +0100
Subject: [PATCH 09/10] chore: add changelog entry

---
 news/changelog-1.9.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/news/changelog-1.9.md b/news/changelog-1.9.md
index 9c327bc5e1d..0245ff5346f 100644
--- a/news/changelog-1.9.md
+++ b/news/changelog-1.9.md
@@ -79,6 +79,7 @@ All changes included in 1.9:
 - ([#13570](https://github.com/quarto-dev/quarto-cli/pull/13570)): Replace Twitter with Bluesky in default blog template and documentation examples. New blog projects now include Bluesky social links instead of Twitter.
 - ([#13716](https://github.com/quarto-dev/quarto-cli/issues/13716)): Fix draft pages showing blank during preview when pre-render scripts are configured.
 - ([#13847](https://github.com/quarto-dev/quarto-cli/pull/13847)): Open graph title with markdown is now processed correctly. (author: @mcanouil)
+- ([#12667](https://github.com/quarto-dev/quarto-cli/pull/12667)): Add support for multiple category selection in listings using Ctrl/Cmd+click. Selected categories are persisted in the URL hash as comma-separated values. (author: @mcanouil)
 
 ### `book`
 

From 48ecb01cc0e54d96d050c8a5097995bb87ce70e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Thu, 15 Jan 2026 00:18:33 +0100
Subject: [PATCH 10/10] test: add tests for multiple category selection in blog

---
 ...c.ts => blog-categories-selection.spec.ts} | 59 +++++++++++++++++++
 1 file changed, 59 insertions(+)
 rename tests/integration/playwright/tests/{blog-simple-blog.spec.ts => blog-categories-selection.spec.ts} (56%)

diff --git a/tests/integration/playwright/tests/blog-simple-blog.spec.ts b/tests/integration/playwright/tests/blog-categories-selection.spec.ts
similarity index 56%
rename from tests/integration/playwright/tests/blog-simple-blog.spec.ts
rename to tests/integration/playwright/tests/blog-categories-selection.spec.ts
index ed6151acc5b..c9f95ea7650 100644
--- a/tests/integration/playwright/tests/blog-simple-blog.spec.ts
+++ b/tests/integration/playwright/tests/blog-categories-selection.spec.ts
@@ -1,6 +1,8 @@
 import { expect, Page, test } from "@playwright/test";
 import { getUrl } from "../src/utils";
 
+declare const process: { platform: string };
+
 const testPages = {
   'posts': 'table.html',
   'posts2': 'default.html',
@@ -64,6 +66,63 @@ Object.entries(testPages).forEach(([postDir, pageName]) => {
       await page.goto(`./blog/simple-blog/_site/${pageName}`);
       await checkCategoryLink(page, '免疫', pageName, 'Welcome To My Blog');
     });
+
+    test(`Multiple category selection with Ctrl+click works for ${pageName}`, async ({ page }) => {
+      await page.goto(`./blog/simple-blog/_site/${pageName}`);
+
+      // Target category sidebar specifically (not post card categories)
+      const categorySidebar = page.locator('.quarto-listing-category');
+      const codeCategory = categorySidebar.locator(`div.category[data-category="${btoa(encodeURIComponent('code'))}"]`);
+      const eurosCategory = categorySidebar.locator(`div.category[data-category="${btoa(encodeURIComponent('euros (€)'))}"]`);
+
+      // Click on "code" category (only Post With Code has this category)
+      await codeCategory.click();
+      await expect(codeCategory).toHaveClass(/active/);
+      await expect(page.getByRole('link', { name: 'Post With Code' })).toBeVisible();
+      await expect(page.getByRole('link', { name: 'Welcome To My Blog' })).toBeHidden();
+
+      // Ctrl+click on "euros (€)" category to add it to selection (only Welcome has this category)
+      const modifier = process.platform === 'darwin' ? 'Meta' : 'Control';
+      await page.keyboard.down(modifier);
+      await eurosCategory.click();
+      await page.keyboard.up(modifier);
+
+      // Both categories should be active
+      await expect(codeCategory).toHaveClass(/active/);
+      await expect(eurosCategory).toHaveClass(/active/);
+
+      // Both posts should be visible (OR logic: posts matching any selected category)
+      await expect(page.getByRole('link', { name: 'Post With Code' })).toBeVisible();
+      await expect(page.getByRole('link', { name: 'Welcome To My Blog' })).toBeVisible();
+
+      // URL hash should contain both categories (comma-separated)
+      const url = page.url();
+      expect(url).toContain('category=');
+      expect(url).toContain(encodeURIComponent('code'));
+      expect(url).toContain(encodeURIComponent('euros (€)'));
+    });
+
+    test(`Deselecting last category with Ctrl+click shows all posts for ${pageName}`, async ({ page }) => {
+      await page.goto(`./blog/simple-blog/_site/${pageName}`);
+
+      // Target category sidebar specifically
+      const categorySidebar = page.locator('.quarto-listing-category');
+      const codeCategory = categorySidebar.locator(`div.category[data-category="${btoa(encodeURIComponent('code'))}"]`);
+
+      // Click on "code" category
+      await codeCategory.click();
+      await expect(codeCategory).toHaveClass(/active/);
+
+      // Ctrl+click on "code" again to deselect it
+      const modifier = process.platform === 'darwin' ? 'Meta' : 'Control';
+      await page.keyboard.down(modifier);
+      await codeCategory.click();
+      await page.keyboard.up(modifier);
+
+      // No category should be active (default state), all posts visible
+      await expect(page.getByRole('link', { name: 'Post With Code' })).toBeVisible();
+      await expect(page.getByRole('link', { name: 'Welcome To My Blog' })).toBeVisible();
+    });
   }
 });