UX: Show error and ability to try again when no suggestions

## 🔍  Overview
When the title suggestions return no suggestions, there is no indication in the UI. In the tag suggester we show a toast when there aren't any suggestions but the request was a success. In this update we make a similar UI indication with a toast for both category and title suggestions. Additionally, for all suggestions we add a "Try again" button to the toast so that suggestions can be generated again if the results yield nothing the first time.

assets/javascripts/discourse/components/suggestion-menus/ai-category-suggester.gjs

@@ -11,7 +11,10 @@ import { ajax } from "discourse/lib/ajax";
 import { popupAjaxError } from "discourse/lib/ajax-error";
 import { i18n } from "discourse-i18n";
 import DMenu from "float-kit/components/d-menu";
-import { MIN_CHARACTER_COUNT } from "../../lib/ai-helper-suggestions";
+import {
+  MIN_CHARACTER_COUNT,
+  showSuggestionsError,
+} from "../../lib/ai-helper-suggestions";
 
 export default class AiCategorySuggester extends Component {
   @service siteSettings;
@@ -40,9 +43,20 @@ export default class AiCategorySuggester extends Component {
     return this.siteSettings.ai_embeddings_enabled && showTrigger;
   }
 
+  get showDropdown() {
+    if (this.suggestions?.length <= 0) {
+      this.dMenu.close();
+    }
+    return !this.loading && this.suggestions?.length > 0;
+  }
+
   @action
   async loadSuggestions() {
-    if (this.suggestions && !this.dMenu.expanded) {
+    if (
+      this.suggestions &&
+      this.suggestions?.length > 0 &&
+      !this.dMenu.expanded
+    ) {
       return this.suggestions;
     }
 
@@ -65,7 +79,13 @@ export default class AiCategorySuggester extends Component {
           data,
         }
       );
+
       this.suggestions = assistant;
+
+      if (this.suggestions?.length <= 0) {
+        showSuggestionsError(this, this.loadSuggestions.bind(this));
+        return;
+      }
     } catch (error) {
       popupAjaxError(error);
     } finally {
@@ -100,8 +120,14 @@ export default class AiCategorySuggester extends Component {
 
   @action
   onClose() {
+    if (this.suggestions?.length > 0) {
+      // If all suggestions have been used,
+      // re-triggering when no suggestions present
+      // will cause computation issues with
+      // setting the icon, so we prevent it
       this.triggerIcon = "discourse-sparkles";
     }
+  }
 
   <template>
     {{#if this.showSuggestionButton}}
@@ -121,7 +147,7 @@ export default class AiCategorySuggester extends Component {
         {{on "click" this.loadSuggestions}}
       >
         <:content>
-          {{#unless this.loading}}
+          {{#if this.showDropdown}}
             <DropdownMenu as |dropdown|>
               {{#each this.suggestions as |suggestion index|}}
                 <dropdown.item>
@@ -141,7 +167,7 @@ export default class AiCategorySuggester extends Component {
                 </dropdown.item>
               {{/each}}
             </DropdownMenu>
-          {{/unless}}
+          {{/if}}
         </:content>
       </DMenu>
     {{/if}}

assets/javascripts/discourse/components/suggestion-menus/ai-tag-suggester.gjs

@@ -11,7 +11,10 @@ import { ajax } from "discourse/lib/ajax";
 import { popupAjaxError } from "discourse/lib/ajax-error";
 import { i18n } from "discourse-i18n";
 import DMenu from "float-kit/components/d-menu";
-import { MIN_CHARACTER_COUNT } from "../../lib/ai-helper-suggestions";
+import {
+  MIN_CHARACTER_COUNT,
+  showSuggestionsError,
+} from "../../lib/ai-helper-suggestions";
 
 export default class AiTagSuggester extends Component {
   @service siteSettings;
@@ -79,6 +82,7 @@ export default class AiTagSuggester extends Component {
         method: "POST",
         data,
       });
+
       this.suggestions = assistant;
 
       const model = this.args.composer
@@ -92,15 +96,7 @@ export default class AiTagSuggester extends Component {
       }
 
       if (this.suggestions?.length <= 0) {
-        this.toasts.error({
-          class: "ai-suggestion-error",
-          duration: 3000,
-          data: {
-            message: i18n(
-              "discourse_ai.ai_helper.suggest_errors.no_suggestions"
-            ),
-          },
-        });
+        showSuggestionsError(this, this.loadSuggestions.bind(this));
         return;
       }
     } catch (error) {

assets/javascripts/discourse/components/suggestion-menus/ai-title-suggester.gjs

@@ -9,7 +9,10 @@ import { ajax } from "discourse/lib/ajax";
 import { popupAjaxError } from "discourse/lib/ajax-error";
 import { i18n } from "discourse-i18n";
 import DMenu from "float-kit/components/d-menu";
-import { MIN_CHARACTER_COUNT } from "../../lib/ai-helper-suggestions";
+import {
+  MIN_CHARACTER_COUNT,
+  showSuggestionsError,
+} from "../../lib/ai-helper-suggestions";
 
 export default class AiTitleSuggester extends Component {
   @tracked loading = false;
@@ -46,9 +49,20 @@ export default class AiTitleSuggester extends Component {
     return showTrigger;
   }
 
+  get showDropdown() {
+    if (this.suggestions?.length <= 0) {
+      this.dMenu.close();
+    }
+    return !this.loading && this.suggestions?.length > 0;
+  }
+
   @action
   async loadSuggestions() {
-    if (this.suggestions && !this.dMenu.expanded) {
+    if (
+      this.suggestions &&
+      this.suggestions?.length > 0 &&
+      !this.dMenu.expanded
+    ) {
       return this.suggestions;
     }
 
@@ -70,7 +84,13 @@ export default class AiTitleSuggester extends Component {
           data,
         }
       );
+
       this.suggestions = suggestions;
+
+      if (this.suggestions?.length <= 0) {
+        showSuggestionsError(this, this.loadSuggestions.bind(this));
+        return;
+      }
     } catch (error) {
       popupAjaxError(error);
     } finally {
@@ -99,8 +119,14 @@ export default class AiTitleSuggester extends Component {
 
   @action
   onClose() {
+    if (this.suggestions?.length > 0) {
+      // If all suggestions have been used,
+      // re-triggering when no suggestions present
+      // will cause computation issues with
+      // setting the icon, so we prevent it
       this.triggerIcon = "discourse-sparkles";
     }
+  }
 
   <template>
     {{#if this.showSuggestionButton}}
@@ -120,7 +146,7 @@ export default class AiTitleSuggester extends Component {
         {{on "click" this.loadSuggestions}}
       >
         <:content>
-          {{#unless this.loading}}
+          {{#if this.showDropdown}}
             <DropdownMenu as |dropdown|>
               {{#each this.suggestions as |suggestion index|}}
                 <dropdown.item>
@@ -135,7 +161,7 @@ export default class AiTitleSuggester extends Component {
                 </dropdown.item>
               {{/each}}
             </DropdownMenu>
-          {{/unless}}
+          {{/if}}
         </:content>
       </DMenu>
     {{/if}}

assets/javascripts/discourse/lib/ai-helper-suggestions.js

@@ -1 +1,34 @@
+import { getOwner } from "@ember/application";
+import { later } from "@ember/runloop";
+import { i18n } from "discourse-i18n";
+
 export const MIN_CHARACTER_COUNT = 40;
+
+export function showSuggestionsError(context, reloadFn) {
+  const toasts = getOwner(context).lookup("service:toasts");
+
+  toasts.error({
+    class: "ai-suggestion-error",
+    duration: "long",
+    showProgressBar: true,
+    data: {
+      message: i18n("discourse_ai.ai_helper.suggest_errors.no_suggestions"),
+      actions: [
+        {
+          label: i18n("discourse_ai.ai_helper.context_menu.regen"),
+          icon: "rotate",
+          class: "btn btn-small",
+          action: async (toast) => {
+            toast.close();
+
+            await reloadFn();
+
+            if (context.dMenu?.show && context.suggestions?.length > 0) {
+              later(() => context.dMenu.show(), 50);
+            }
+          },
+        },
+      ],
+    },
+  });
+}

config/locales/client.en.yml

@@ -599,7 +599,7 @@ en:
           trigger: "Ask AI"
           loading: "AI is generating"
           cancel: "Cancel"
-          regen: "Try Again"
+          regen: "Try again"
           confirm: "Confirm"
           discard: "Discard"
           changes: "Suggested edits"