Enhance Search Modal, Error State Handling in Khoj Obsidian Plugin

### Search Modal Enhancements
  - b52cd85 Allow Reranking results using Keybinding from Khoj Search Modal
  - 580f4ac Add hints to Modal for available Keybindings
  - da49ea2 Add placeholder text to modal in Khoj Obsidian plugin
  
### Handle Failure to Connect to Khoj Backend
Load plugin but warn on failure to connect to Khoj backend

- f046a95 Track connectedToBackend as a setting. Use it across obsidian plugin to:
  - Disable command if not connected to backend
  - Trigger warning notice on clicking Khoj ribbon if not connected to backend
  - Show warning at top of Khoj Obsidian plugin settings pane
- 768e874 Load obsidian plugin even if fail to connect to backend but show warning
  - Allows user to see reason for failure to try resolve it
  - Allows user to update Khoj URL settings to point to URL of Khoj server
  
### Miscellaneous
- 7991ab7 Add button in Obsidian plugin settings to force re-indexing your vault
  - Useful if index gets corrupted

src/interface/obsidian/src/main.ts

@@ -1,4 +1,4 @@
-import { Plugin } from 'obsidian';
+import { Notice, Plugin } from 'obsidian';
 import { KhojSetting, KhojSettingTab, DEFAULT_SETTINGS } from 'src/settings'
 import { KhojModal } from 'src/modal'
 import { configureKhojBackend } from './utils';
@@ -14,18 +14,22 @@ export default class Khoj extends Plugin {
         this.addCommand({
             id: 'search',
             name: 'Search',
-            callback: () => {
+            checkCallback: (checking) => {
-                new KhojModal(this.app, this.settings).open();
+                if (!checking && this.settings.connectedToBackend)
+                    new KhojModal(this.app, this.settings).open();
+                return this.settings.connectedToBackend;
             }
         });
 
         // Create an icon in the left ribbon.
         this.addRibbonIcon('search', 'Khoj', (_: MouseEvent) => {
             // Called when the user clicks the icon.
-            new KhojModal(this.app, this.settings).open();
+            this.settings.connectedToBackend
+            ? new KhojModal(this.app, this.settings).open()
+            : new Notice(`❗️Ensure Khoj backend is running and Khoj URL is pointing to it in the plugin settings`);
         });
 
-        // Add a settings tab so the user can configure various aspects of the plugin
+        // Add a settings tab so the user can configure khoj
         this.addSettingTab(new KhojSettingTab(this.app, this));
     }
 
@@ -41,7 +45,7 @@ export default class Khoj extends Plugin {
     }
 
     async saveSettings() {
-        await this.saveData(this.settings)
+        await configureKhojBackend(this.settings)
-            .then(() => configureKhojBackend(this.settings));
+            .then(() => this.saveData(this.settings));
     }
 }

src/interface/obsidian/src/modal.ts

@@ -1,4 +1,4 @@
-import { App, SuggestModal, Notice, request, MarkdownRenderer } from 'obsidian';
+import { App, SuggestModal, Notice, request, MarkdownRenderer, Instruction, Platform } from 'obsidian';
 import { KhojSetting } from 'src/settings';
 import { getVaultAbsolutePath } from 'src/utils';
 
@@ -9,16 +9,54 @@ export interface SearchResult {
 
 export class KhojModal extends SuggestModal<SearchResult> {
     setting: KhojSetting;
+    rerank: boolean;
 
     constructor(app: App, setting: KhojSetting) {
         super(app);
         this.setting = setting;
+        this.rerank = false;
+
+        // Register Modal Keybindings to Rerank Results
+        this.scope.register(['Mod'], 'Enter', async () => {
+            this.rerank = true
+            let results = await this.getSuggestions(this.inputEl.value);
+
+            this.resultContainerEl.empty();
+            results.forEach((result) => {
+                this.renderSuggestion(result, this.resultContainerEl);
+            });
+            this.rerank = false
+        });
+
+        // Add Hints to Modal for available Keybindings
+        const modalInstructions: Instruction[] = [
+            {
+                command: '↑↓',
+                purpose: 'to navigate',
+            },
+            {
+                command: '↵',
+                purpose: 'to open',
+            },
+            {
+                command: Platform.isMacOS ? 'cmd ↵': 'ctrl ↵',
+                purpose: 'to rerank',
+            },
+            {
+                command: 'esc',
+                purpose: 'to dismiss',
+            },
+        ]
+        this.setInstructions(modalInstructions);
+
+        // Set Placeholder Text for Modal
+        this.setPlaceholder('Search with Khoj...');
     }
 
     async getSuggestions(query: string): Promise<SearchResult[]> {
         // Query Khoj backend for search results
-        var searchUrl = `${this.setting.khojUrl}/api/search?q=${query}&n=${this.setting.resultsCount}&t=markdown`
+        let searchUrl = `${this.setting.khojUrl}/api/search?q=${query}&n=${this.setting.resultsCount}&r=${this.rerank}&t=markdown`
-        var results = await request(searchUrl)
+        let results = await request(searchUrl)
             .then(response => JSON.parse(response))
             .then(data => {
                 return data.map((result: any) => {

src/interface/obsidian/src/settings.ts

@@ -1,4 +1,4 @@
-import { App, PluginSettingTab, Setting } from 'obsidian';
+import { App, PluginSettingTab, request, Setting } from 'obsidian';
 import Khoj from 'src/main';
 import { getVaultAbsolutePath } from 'src/utils';
 
@@ -6,12 +6,14 @@ export interface KhojSetting {
     resultsCount: number;
     khojUrl: string;
     obsidianVaultPath: string;
+    connectedToBackend: boolean;
 }
 
 export const DEFAULT_SETTINGS: KhojSetting = {
     resultsCount: 6,
     khojUrl: 'http://localhost:8000',
-    obsidianVaultPath: getVaultAbsolutePath()
+    obsidianVaultPath: getVaultAbsolutePath(),
+    connectedToBackend: false,
 }
 
 export class KhojSettingTab extends PluginSettingTab {
@@ -25,8 +27,15 @@ export class KhojSettingTab extends PluginSettingTab {
     display(): void {
         const { containerEl } = this;
         containerEl.empty();
+
+        // Add notice if unable to connect to khoj backend
+        if (!this.plugin.settings.connectedToBackend) {
+            containerEl.createEl('small', { text: '❗Ensure Khoj backend is running and Khoj URL is correctly set below' });
+        }
+
+        // Add khoj settings configurable from the plugin settings tab
         new Setting(containerEl)
-            .setName('Vault Paths')
+            .setName('Vault Path')
             .setDesc('The Obsidian Vault to search with Khoj')
             .addText(text => text
                 .setValue(`${this.plugin.settings.obsidianVaultPath}`)
@@ -44,7 +53,7 @@ export class KhojSettingTab extends PluginSettingTab {
                     await this.plugin.saveSettings();
                 }));
          new Setting(containerEl)
-            .setName('Number of Results')
+            .setName('Results Count')
             .setDesc('The number of search results to show')
             .addText(text => text
                 .setPlaceholder('6')
@@ -53,5 +62,14 @@ export class KhojSettingTab extends PluginSettingTab {
                     this.plugin.settings.resultsCount = parseInt(value);
                     await this.plugin.saveSettings();
                 }));
+        new Setting(containerEl)
+            .setName('Index Vault')
+            .setDesc('Manually force Khoj to re-index your Obsidian Vault')
+            .addButton(button => button
+                .setButtonText('Update')
+                .onClick(async () => {
+                    await request(`${this.plugin.settings.khojUrl}/api/update?t=markdown&force=true`);
+                }
+            ));
     }
 }

src/interface/obsidian/src/utils.ts

@@ -13,16 +13,25 @@ export async function configureKhojBackend(setting: KhojSetting) {
     let mdInVault = `${setting.obsidianVaultPath}/**/*.md`;
     let khojConfigUrl = `${setting.khojUrl}/api/config/data`;
 
-    // Load khoj app config from backend API, Update Markdown config and save
+    // Check if khoj backend is configured, show error if backend is not running
-    let khoj_configured = await request(khojConfigUrl)
+    let khoj_already_configured = await request(khojConfigUrl)
-        .then(response => response !== "null");
+        .then(response => {
+            setting.connectedToBackend = true;
+            return response !== "null"
+        })
+        .catch(error => {
+            setting.connectedToBackend = false;
+            new Notice(`❗️Ensure Khoj backend is running and Khoj URL is pointing to it in the plugin settings.\n\n${error}`);
+        })
+    // Short-circuit configuring khoj if unable to connect to khoj backend
+    if (!setting.connectedToBackend) return;
 
     // Get current config if khoj backend configured, else get default config from khoj backend
-    await request(khoj_configured ? khojConfigUrl : `${khojConfigUrl}/default`)
+    await request(khoj_already_configured ? khojConfigUrl : `${khojConfigUrl}/default`)
         .then(response => JSON.parse(response))
         .then(data => {
             // If khoj backend not configured yet
-            if (!khoj_configured) {
+            if (!khoj_already_configured) {
                 // Create khoj content-type config with only markdown configured
                 let khojObsidianPluginPath = `${setting.obsidianVaultPath}/${this.app.vault.configDir}/plugins/khoj/`;
                 data["content-type"] = {
@@ -70,9 +79,10 @@ export async function configureKhojBackend(setting: KhojSetting) {
                 updateKhojBackend(setting.khojUrl, data);
                 console.log(`Khoj: Updated markdown config in khoj backend config:\n${JSON.stringify(data["content-type"]["markdown"])}`)
             }
+            new Notice(`✅ Successfully Setup Khoj`);
         })
         .catch(error => {
-            new Notice(`Ensure Khoj backend is running and Khoj URL is correct in the Khoj plugin settings.\nError: ${error}`);
+            new Notice(`❗️Failed to configure Khoj backend. Contact developer on Github. \n\nError: ${error}`);
         })
 }