feat: CTRL+SHIFT+CLICK on URI to find all triples where URI is object

docs/user-guide.md

@@ -712,19 +712,19 @@ PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>""" ;
 
 ### URI Explorer
 
-Quickly explore RDF resources by Ctrl+clicking on URIs in your query.
+Quickly explore RDF resources by Ctrl+(Shift+)clicking on URIs in your query.
 
 **How It Works:**
 
 1. Hold `Ctrl` and click any URI in the query editor
-2. Matgui automatically generates and executes a CONSTRUCT query exploring:
-   - Outgoing triples (where the URI is the subject)
-   - Incoming triples (where the URI is the object)
+2. MatGUI automatically generates and executes a CONSTRUCT query where the URI is the **subject**
 3. Results appear without modifying your original query
 4. View the resource's connections in the results viewer
 
+Alternatively, use `Ctrl`+`Shift` and click on the URI to executes a CONSTRUCT query where the URI is the **object**.
+
 **Example:**
-Ctrl+clicking on `http://dbpedia.org/resource/European_Union` automatically queries for all triples related to the European Union.
+Ctrl+clicking on `http://dbpedia.org/resource/European_Union` automatically queries for all triples where the European Union is the subject of.
 
 ### Query Tabs
 
@@ -1396,7 +1396,8 @@ Shows the raw response from the SPARQL endpoint.
 - Code folding for nested structures
 - Copy to clipboard functionality
 - Line numbers
-- **Ctrl+Click on a URI** to run a `DESCRIBE` query for that resource and append the returned triples to the response view (similar to the Graph plugin's node expansion)
+- **Ctrl+Click on a URI** executes a CONSTRUCT query where the URI is the **subject** and append the returned triples to the response view (similar to the Graph plugin's node expansion)
+- **Ctrl+Click on a URI** executes a CONSTRUCT query where the URI is the **object** and append the returned triples to the response view (similar to the Graph plugin's node expansion)
 
 **Best For:**
 
@@ -1800,17 +1801,18 @@ Master Matgui with these keyboard shortcuts for faster querying.
 
 ### Query Editor (YASQE)
 
-| Shortcut                   | Action                           |
-| -------------------------- | -------------------------------- |
-| `Ctrl+Enter` / `Cmd+Enter` | Execute query                    |
-| `Ctrl+Space`               | Trigger autocomplete             |
-| `Ctrl+S`                   | Save query to local storage      |
-| `Ctrl+Shift+F`             | Format query                     |
-| `Ctrl+/`                   | Toggle comment on selected lines |
-| `Ctrl+Shift+D`             | Duplicate current line           |
-| `Ctrl+Shift+K`             | Delete current line              |
-| `Esc`                      | Remove focus from editor         |
-| `Ctrl+Click` (on URI)      | Explore URI connections          |
+| Shortcut                    | Action                           |
+| --------------------------- | -------------------------------- |
+| `Ctrl+Enter` / `Cmd+Enter`  | Execute query                    |
+| `Ctrl+Space`                | Trigger autocomplete             |
+| `Ctrl+S`                    | Save query to local storage      |
+| `Ctrl+Shift+F`              | Format query                     |
+| `Ctrl+/`                    | Toggle comment on selected lines |
+| `Ctrl+Shift+D`              | Duplicate current line           |
+| `Ctrl+Shift+K`              | Delete current line              |
+| `Esc`                       | Remove focus from editor         |
+| `Ctrl+Click` (on URI)       | Explore outgoing URI connections |
+| `Ctrl+Shift+Click` (on URI) | Explore incoming URI connections |
 
 ### Fullscreen
 

packages/yasgui/src/Tab.ts

@@ -9,6 +9,8 @@ import {
   Config as YasrConfig,
   PersistentConfig as YasrPersistentConfig,
   PluginQueryOptions as YasrPluginQueryOptions,
+  buildSubjectOfQuery,
+  buildObjectOfQuery,
 } from "@matdata/yasr";
 import { mapValues, eq, mergeWith, words, deburr, invert } from "lodash-es";
 import * as shareLink from "./linkUtils";
@@ -1564,21 +1566,15 @@ export class Tab extends EventEmitter {
       }
     }
 
-    // Construct the query
-    const constructQuery = `CONSTRUCT {   
-  ?s_left ?p_left ?target .
-  ?target ?p_right ?o_right .
-}
-WHERE {
-  BIND(<${uri}> as ?target)
-  {
-    ?s_left ?p_left ?target .
-  }
-  UNION
-  {
-    ?target ?p_right ?o_right .
-  }  
-} LIMIT 1000`;
+    // Construct the query based on whether Shift is held
+    let constructQuery: string;
+    if (event.shiftKey) {
+      // Ctrl+Shift+Click: find all triples where URI is the object
+      constructQuery = buildObjectOfQuery(uri);
+    } else {
+      // Ctrl+Click: find all triples where URI is the subject
+      constructQuery = buildSubjectOfQuery(uri);
+    }
 
     // Execute query in background without changing editor content
     // Note: void operator is intentional - errors are handled in the catch block of executeBackgroundQuery

packages/yasgui/src/TabSettingsModal.ts

@@ -2032,7 +2032,8 @@ export default class TabSettingsModal {
           { keys: ["Ctrl+Shift+D", "Cmd+Shift+D"], description: "Duplicate current line" },
           { keys: ["Ctrl+Shift+K", "Cmd+Shift+K"], description: "Delete current line" },
           { keys: ["Esc"], description: "Remove focus from editor" },
-          { keys: ["Ctrl+Click"], description: "Explore URI connections (on URI)" },
+          { keys: ["Ctrl+Click"], description: "Find triples where URI is subject" },
+          { keys: ["Ctrl+Shift+Click"], description: "Find triples where URI is object" },
         ],
       },
       {

packages/yasqe/src/index.ts

@@ -228,7 +228,10 @@ export class Yasqe extends EditorFacade {
 
     if (token && token.type === "variable-3") {
       // Token type "variable-3" represents URIs (IRI_REF)
-      this.showNotification("uri-describe-hint", "Hold CTRL - left mouse click on URI to DESCRIBE");
+      this.showNotification(
+        "uri-describe-hint",
+        "CTRL+click: find triples where URI is subject. CTRL+SHIFT+click: find triples where URI is object.",
+      );
     } else {
       this.hideNotification("uri-describe-hint");
     }

packages/yasr/src/index.ts

@@ -792,5 +792,6 @@ Yasr.registerPlugin("response", YasrPluginResponse.default as any);
 Yasr.registerPlugin("error", YasrPluginError.default as any);
 
 export type { Plugin, DownloadInfo } from "./plugins";
+export { buildSubjectOfQuery, buildObjectOfQuery } from "./plugins/response/uriUtils";
 
 export default Yasr;

packages/yasr/src/plugins/response/index.ts

@@ -14,7 +14,12 @@
 import { javascript } from "@codemirror/legacy-modes/mode/javascript";
 import { addClass, removeClass } from "@matdata/yasgui-utils";
 import { DeepReadonly } from "ts-essentials";
-import { extractUriAtOffset, buildDescribeQuery } from "./uriUtils";
+import {
+  extractUriAtOffset,
+  buildSubjectOfQuery,
+  buildObjectOfQuery,
+  stripDuplicatePrefixDeclarations,
+} from "./uriUtils";
 
 export interface PluginConfig {
   maxLines: number;
@@ -27,7 +32,7 @@
   private config: DeepReadonly<PluginConfig>;
   private overLay: HTMLDivElement | undefined;
   private cm: EditorView | undefined;
-  /** Turtle appended to the response view through Ctrl+Click DESCRIBE actions. */
+  /** Turtle appended to the response view through Ctrl+Click URI exploration actions. */
   private appendedContent = "";
   constructor(yasr: Yasr) {
     this.yasr = yasr;
@@ -112,7 +117,7 @@
     if (type === "json") return json();
     if (type === "xml") return xml();
     if (type === "ttl") return turtle();
     if (type === "n-triples") return turtle();
     const contentType = this.yasr.results?.getContentType() || "";
     if (contentType.indexOf("json") >= 0) return json();
     if (contentType.indexOf("xml") >= 0 || contentType.indexOf("html") >= 0) return xml();
@@ -130,8 +135,8 @@
   }
 
   /**
-   * Ctrl/Cmd+Click on a URI in the response view runs a `DESCRIBE` query for that
-   * URI and appends the result to the response view (similar to the graph plugin).
+   * Ctrl/Cmd+Click on a URI runs a CONSTRUCT query for triples where the URI is the subject.
+   * Ctrl/Cmd+Shift+Click runs a CONSTRUCT query for triples where the URI is the object.
    */
   private handleMouseDown = (event: MouseEvent) => {
     if (!event.ctrlKey && !event.metaKey) return;
@@ -148,42 +153,75 @@
 
     event.preventDefault();
     event.stopPropagation();
-    void this.describeUri(uri);
+
+    if (event.shiftKey) {
+      void this.runObjectOfQuery(uri);
+    } else {
+      void this.runSubjectOfQuery(uri);
+    }
   };
 
-  private async describeUri(uri: string) {
+  private async runSubjectOfQuery(uri: string) {
+    if (!this.yasr.config.executeQuery) return;
+    const cmAtStart = this.cm;
+    if (!cmAtStart) return;
+
+    const query = buildSubjectOfQuery(uri);
+    try {
+      this.yasr.showLoading();
+      const response = await this.yasr.executeQuery(query, { acceptHeader: this.getConstructAcceptHeader() });
+      if (this.cm !== cmAtStart) return;
+
+      const content = this.getResponseContent(response);
+      if (content) {
+        this.appendToView(`\n\n# Triples where <${uri}> is subject\n${content.trim()}\n`);
+      } else {
+        this.appendToView(`\n\n# Triples where <${uri}> is subject: no data\n`);
+      }
+    } catch (error) {
+      if (this.cm !== cmAtStart) return;
+
+      console.error("Subject-of query failed:", error);
+      const message = error instanceof Error ? error.message : String(error);
+      this.appendToView(`\n\n# Triples where <${uri}> is subject failed: ${message}\n`);
+    } finally {
+      if (this.cm === cmAtStart) this.yasr.hideLoading();
+    }
+  }
+
+  private async runObjectOfQuery(uri: string) {
     if (!this.yasr.config.executeQuery) return;
     const cmAtStart = this.cm;
     if (!cmAtStart) return;
 
-    const query = buildDescribeQuery(uri);
+    const query = buildObjectOfQuery(uri);
     try {
       this.yasr.showLoading();
-      const response = await this.yasr.executeQuery(query, { acceptHeader: this.getDescribeAcceptHeader() });
+      const response = await this.yasr.executeQuery(query, { acceptHeader: this.getConstructAcceptHeader() });
       if (this.cm !== cmAtStart) return;
 
       const content = this.getResponseContent(response);
       if (content) {
-        this.appendToView(`\n\n# DESCRIBE <${uri}>\n${content.trim()}\n`);
+        this.appendToView(`\n\n# Triples where <${uri}> is object\n${content.trim()}\n`);
       } else {
-        this.appendToView(`\n\n# DESCRIBE <${uri}> returned no data\n`);
+        this.appendToView(`\n\n# Triples where <${uri}> is object: no data\n`);
       }
     } catch (error) {
       if (this.cm !== cmAtStart) return;
 
-      console.error("DESCRIBE query failed:", error);
+      console.error("Object-of query failed:", error);
       const message = error instanceof Error ? error.message : String(error);
-      this.appendToView(`\n\n# DESCRIBE <${uri}> failed: ${message}\n`);
+      this.appendToView(`\n\n# Triples where <${uri}> is object failed: ${message}\n`);
     } finally {
       if (this.cm === cmAtStart) this.yasr.hideLoading();
     }
   }
 
   /**
-   * Pick an Accept header for the DESCRIBE request. When the current response is an
-   * RDF graph format, reuse it so the appended triples match what is already shown.
+   * Pick an Accept header for follow-up CONSTRUCT requests. When the current response
+   * is an RDF graph format, reuse it so the appended triples match what is shown.
    */
-  private getDescribeAcceptHeader(): string {
+  private getConstructAcceptHeader(): string {
     const contentType = this.yasr.results?.getContentType();
     if (contentType) {
       const lower = contentType.toLowerCase();
@@ -211,12 +249,13 @@
   }
 
   /**
-   * Append text (a DESCRIBE result or a status message) to the response view and
-   * make sure the full content is revealed.
+   * Append text (query result or status message) to the response view and make sure
+   * the full content is revealed.
    */
   private appendToView(text: string) {
     if (!this.cm || !text) return;
-    this.appendedContent += text;
+    const existingVisibleContent = (this.yasr.results?.getOriginalResponseAsString() || "") + this.appendedContent;
+    this.appendedContent += stripDuplicatePrefixDeclarations(text, existingVisibleContent);
     // Reveal the full response together with the appended DESCRIBE results.
     this.showMore();
   }

packages/yasr/src/plugins/response/uriUtils.ts

@@ -1,5 +1,5 @@
 /**
- * Standalone helpers for the Response plugin's "Ctrl+Click a URI to DESCRIBE" feature.
+ * Standalone helpers for the Response plugin's Ctrl+Click URI exploration feature.
  *
  * These functions are intentionally free of any DOM or CodeMirror dependencies so
  * that they can be unit-tested in isolation.
@@ -9,6 +9,8 @@
 const ANGLE_IRI_RE = /<([^<>\s"{}|\\^`]+)>/g;
 // Matches bare or quoted URIs as they appear in JSON / XML / CSV responses, e.g. `"http://example.org/foo"`
 const BARE_URI_RE = /(?:https?|urn|ftp|mailto):[^\s<>"'`{}|\\^[\]]+/g;
+// Matches Turtle/SPARQL prefix declarations such as `@prefix ex: <...> .` and `PREFIX ex: <...>`.
+const PREFIX_DECL_RE = /^\s*(?:@prefix|PREFIX)\s+(\w*):\s*<[^>]+>\s*\.?\s*$/i;
 
 /**
  * Remove trailing punctuation that is commonly adjacent to a URI in a serialized
@@ -57,11 +59,59 @@ export function extractUriAtOffset(text: string, offset: number): string | undef
 }
 
 /**
- * Build a `CONSTRUCT` query for the given URI.
+ * Build a CONSTRUCT query that retrieves all triples where the given URI is the subject.
  *
- * @param uri The URI to describe.
- * @returns A SPARQL `CONSTRUCT` query string with the uri as the subject.
+ * @param uri The URI to look up as a subject.
+ * @returns A SPARQL `CONSTRUCT` query string.
  */
-export function buildDescribeQuery(uri: string): string {
+export function buildSubjectOfQuery(uri: string): string {
   return `CONSTRUCT { <${uri}> ?p ?o } WHERE { <${uri}> ?p ?o }`;
 }
+
+/**
+ * Build a CONSTRUCT query that retrieves all triples where the given URI is the object.
+ *
+ * @param uri The URI to look up as an object.
+ * @returns A SPARQL `CONSTRUCT` query string.
+ */
+export function buildObjectOfQuery(uri: string): string {
+  return `CONSTRUCT { ?s ?p <${uri}> } WHERE { ?s ?p <${uri}> } LIMIT 1000`;
+}
+
+/**
+ * Remove duplicate prefix declarations from a text block.
+ *
+ * Prefixes are considered duplicates by label (case-insensitive), and can be
+ * deduplicated against already-rendered content in the response viewer.
+ */
+export function stripDuplicatePrefixDeclarations(text: string, existingText = ""): string {
+  if (!text) return text;
+
+  const seenLabels = new Set<string>();
+  const addSeenLabels = (source: string) => {
+    for (const line of source.split("\n")) {
+      const match = line.match(PREFIX_DECL_RE);
+      if (!match) continue;
+      seenLabels.add(match[1].toLowerCase());
+    }
+  };
+
+  addSeenLabels(existingText);
+
+  const deduplicatedLines: string[] = [];
+  for (const line of text.split("\n")) {
+    const match = line.match(PREFIX_DECL_RE);
+    if (!match) {
+      deduplicatedLines.push(line);
+      continue;
+    }
+
+    const label = match[1].toLowerCase();
+    if (seenLabels.has(label)) continue;
+
+    seenLabels.add(label);
+    deduplicatedLines.push(line);
+  }
+
+  return deduplicatedLines.join("\n");
+}