fix: LlamaParse json mode returns array + basic example (run-llama#914)

Co-authored-by: Marcus Schiesser <[email protected]>
Co-authored-by: Marcus Schiesser <[email protected]>

examples/readers/package.json

@@ -11,7 +11,8 @@
     "start:pdf": "node --import tsx ./src/pdf.ts",
     "start:llamaparse": "node --import tsx ./src/llamaparse.ts",
     "start:notion": "node --import tsx ./src/notion.ts",
-    "start:llamaparse-dir": "node --import tsx ./src/simple-directory-reader-with-llamaparse.ts"
+    "start:llamaparse-dir": "node --import tsx ./src/simple-directory-reader-with-llamaparse.ts",
+    "start:llamaparse-json": "node --import tsx ./src/llamaparse-json.ts"
   },
   "dependencies": {
     "llamaindex": "*"

examples/readers/src/llamaparse-json.ts

@@ -0,0 +1,30 @@
+import fs from "fs/promises";
+import { LlamaParseReader } from "llamaindex";
+
+async function main() {
+  // Load PDF using LlamaParse json mode
+  const reader = new LlamaParseReader({ resultType: "json" });
+  const jsonObjs = await reader.loadJson("../data/uber_10q_march_2022.pdf");
+
+  // Write the JSON objects to a file
+  try {
+    await fs.writeFile("jsonObjs.json", JSON.stringify(jsonObjs, null, 4));
+    console.log("Array of JSON objects has been written to jsonObjs.json");
+  } catch (e) {
+    console.error("Error writing jsonObjs.json", e);
+  }
+
+  const jsonList = jsonObjs[0]["pages"];
+
+  // Write the list of JSON objects as a single array to a file
+  try {
+    await fs.writeFile("jsonList.json", JSON.stringify(jsonList, null, 4));
+    console.log(
+      "List of JSON objects as single array has been written to jsonList.json",
+    );
+  } catch (e) {
+    console.error("Error writing jsonList.json", e);
+  }
+}
+
+main().catch(console.error);

packages/core/src/readers/LlamaParseReader.ts

@@ -162,10 +162,10 @@ export class LlamaParseReader extends FileReader {
   // Create a job for the LlamaParse API
   private async createJob(data: Buffer): Promise<string> {
     // Load data, set the mime type
-    const mimeType = await this.getMimeType(data);
+    const { mimeType, extension } = await this.getMimeType(data);
 
     if (this.verbose) {
-      console.log(`Starting load for file with mimeType: ${mimeType}`);
+      console.log(`Starting load for ${extension} file`);
     }
 
     const body = new FormData();
@@ -290,25 +290,25 @@ export class LlamaParseReader extends FileReader {
     ];
   }
   /**
-   * Loads data from a file and returns its contents as a JSON object.
+   * Loads data from a file and returns an array of JSON objects.
    * To be used with resultType = "json"
    *
    * @param {string} file - The path to the file to be loaded.
-   * @return {Promise<Record<string, any>>} A Promise that resolves to the JSON object.
+   * @return {Promise<Record<string, any>[]>} A Promise that resolves to an array of JSON objects.
    */
-  async loadJson(file: string): Promise<Record<string, any>> {
+  async loadJson(file: string): Promise<Record<string, any>[]> {
     const data = await fs.readFile(file);
     // Creates a job for the file
     const jobId = await this.createJob(data);
     if (this.verbose) {
       console.log(`Started parsing the file under job id ${jobId}`);
     }
 
-    // Return results as JSON object
+    // Return results as an array of JSON objects (same format as Python version of the reader)
     const resultJson = await this.getJobResult(jobId, "json");
     resultJson.job_id = jobId;
     resultJson.file_path = file;
-    return resultJson;
+    return [resultJson];
   }
 
   /**
@@ -370,18 +370,19 @@ export class LlamaParseReader extends FileReader {
     return images;
   }
 
-  private async getMimeType(data: Buffer): Promise<string> {
-    const mimes = filetypemime(data);
-    const validMime = mimes.find((mime) =>
-      Object.values(SupportedFiles).includes(mime),
-    );
-    if (!validMime) {
+  private async getMimeType(
+    data: Buffer,
+  ): Promise<{ mimeType: string; extension: string }> {
+    const mimes = filetypemime(data); // Get an array of possible MIME types
+    const extension = Object.keys(SupportedFiles).find(
+      (ext) => SupportedFiles[ext] === mimes[0],
+    ); // Find the extension for the first MIME type
+    if (!extension) {
       const supportedExtensions = Object.keys(SupportedFiles).join(", ");
       throw new Error(
-        `File has type "${mimes}" which does not match supported MIME Types. Supported formats include: ${supportedExtensions}`,
+        `File has type "${mimes[0]}" which does not match supported MIME Types. Supported formats include: ${supportedExtensions}`,
       );
     }
-
-    return validMime;
+    return { mimeType: mimes[0], extension }; // Return the first MIME type and its corresponding extension
   }
 }