feat: add empty filter

Author: HerringtonDarkholme

website/src/catalog/RuleList.vue

@@ -15,35 +15,112 @@ const ruleMetaData = computed(() => getRuleMetaData(props.filter))
 </script>
 
 <template>
-  <h3>
-    Rule List
-    <NumberFlow
-      :plugins="[continuous]"
-      :value="ruleMetaData.length"
-    />
-  </h3>
-  <TransitionGroup class="rule-list" tag="ul">
-    <RuleItem
-      v-for="meta in ruleMetaData"
-      :key="meta.language + meta.id"
-      :meta="meta"
-      :filter="filter"
-    />
-  </TransitionGroup>
+  <div class="rule-list-container">
+    <h3>
+      Rule List
+      <NumberFlow
+        prefix="("
+        suffix=")"
+        :plugins="[continuous]"
+        :value="ruleMetaData.length"
+      />
+    </h3>
+    <TransitionGroup class="rule-list" tag="ul">
+      <RuleItem
+        v-for="meta in ruleMetaData"
+        :key="meta.language + meta.id"
+        :meta="meta"
+        :filter="filter"
+      />
+    </TransitionGroup>
+    <Transition name="not-found">
+      <div class="no-rule" v-if="ruleMetaData.length === 0">
+        <p class="title">No Matching Rule</p>
+        <hr class="divider"/>
+        <div class="actions">
+          Try resetting the filter to discover all rules.<br/>
+          Contributing a new rule is also warmly welcomed. 🎉
+          <ol>
+            <li>
+              Read the
+              <a href="/reference/rule.html" target="_blank">rule</a> and
+              <a href="/reference/yaml.html" target="_blank">YAML</a> doc.</li>
+            <li>Write your own rule in the
+              <a href="/playground.html" target="_blank">
+                playground
+              </a>.
+            </li>
+            <li>
+              Add a new example in the ast-grep
+                <a href="https://github.com/ast-grep/ast-grep.github.io/tree/main/website/catalog" target="_blank">
+                  website repo
+                </a>.
+            </li>
+          </ol>
+        </div>
+      </div>
+    </Transition>
+  </div>
 </template>
 
 <style scoped>
+.rule-list-container {
+  position: relative;
+  min-height: 280px;
+}
 h3 {
   margin: 20px 0 8px;
-  display: flex;
-  justify-content: space-between;
 }
 .rule-list {
   list-style: none;
   padding: 0;
   margin: 0;
 }
 
+.divider {
+  margin: 24px auto 18px;
+  width: 64px;
+  height: 1px;
+  background-color: var(--vp-c-divider);
+}
+
+.title {
+  padding-top: 12px;
+  letter-spacing: 2px;
+  line-height: 20px;
+  font-size: 20px;
+  font-weight: 700;
+  margin: 0;
+}
+.no-rule {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  flex-direction: column;
+  width: 100%;
+}
+.actions {
+  margin: 0 auto;
+  font-size: 14px;
+  font-weight: 500;
+  color: var(--vp-c-text-2);
+}
+
+.not-found-enter-active,
+.not-found-leave-active {
+  transition: all 0.4s cubic-bezier(0.59, 0.12, 0.34, 0.95);
+}
+.not-found-enter-from,
+.not-found-leave-to {
+  opacity: 0;
+  transform: translateY(10px) scale(0.9);
+}
+.not-found-leave-active {
+  position: absolute;
+  /* this is somehow hard coded*/
+  top: 38px;
+}
+
 .v-move,
 .v-enter-active,
 .v-leave-active {
@@ -61,8 +138,5 @@ h3 {
 }
 number-flow-vue::part(integer) {
   font-variant-numeric: tabular-nums;
-  font-style: italic;
-  font-weight: 500;
 }
-
 </style>