feat: add embedchain javascript package (#576)

embedchain-js/embedchain/loaders/PdfFile.ts

@@ -0,0 +1,58 @@
+import type { TextContent } from 'pdfjs-dist/types/src/display/api';
+
+import type { LoaderResult, Metadata } from '../models';
+import { cleanString } from '../utils';
+import { BaseLoader } from './BaseLoader';
+
+const pdfjsLib = require('pdfjs-dist');
+
+interface Page {
+  page_content: string;
+}
+
+class PdfFileLoader extends BaseLoader {
+  static async getPagesFromPdf(url: string): Promise<Page[]> {
+    const loadingTask = pdfjsLib.getDocument(url);
+    const pdf = await loadingTask.promise;
+    const { numPages } = pdf;
+
+    const promises = Array.from({ length: numPages }, async (_, i) => {
+      const page = await pdf.getPage(i + 1);
+      const pageText: TextContent = await page.getTextContent();
+      const pageContent: string = pageText.items
+        .map((item) => ('str' in item ? item.str : ''))
+        .join(' ');
+
+      return {
+        page_content: pageContent,
+      };
+    });
+
+    return Promise.all(promises);
+  }
+
+  // eslint-disable-next-line class-methods-use-this
+  async loadData(url: string): Promise<LoaderResult> {
+    const pages: Page[] = await PdfFileLoader.getPagesFromPdf(url);
+    const output: LoaderResult = [];
+
+    if (!pages.length) {
+      throw new Error('No data found');
+    }
+
+    pages.forEach((page) => {
+      let content: string = page.page_content;
+      content = cleanString(content);
+      const metaData: Metadata = {
+        url,
+      };
+      output.push({
+        content,
+        metaData,
+      });
+    });
+    return output;
+  }
+}
+
+export { PdfFileLoader };