feat: add embedchain javascript package (#576)

embedchain-js/embedchain/loaders/BaseLoader.ts

@@ -0,0 +1,5 @@
+import type { Input, LoaderResult } from '../models';
+
+export abstract class BaseLoader {
+  abstract loadData(src: Input): Promise<LoaderResult>;
+}

embedchain-js/embedchain/loaders/LocalQnaPair.ts

@@ -0,0 +1,21 @@
+import type { LoaderResult, QnaPair } from '../models';
+import { BaseLoader } from './BaseLoader';
+
+class LocalQnaPairLoader extends BaseLoader {
+  // eslint-disable-next-line class-methods-use-this
+  async loadData(content: QnaPair): Promise<LoaderResult> {
+    const [question, answer] = content;
+    const contentText = `Q: ${question}\nA: ${answer}`;
+    const metaData = {
+      url: 'local',
+    };
+    return [
+      {
+        content: contentText,
+        metaData,
+      },
+    ];
+  }
+}
+
+export { LocalQnaPairLoader };

embedchain-js/embedchain/loaders/PdfFile.ts

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+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 };

embedchain-js/embedchain/loaders/WebPage.ts

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+import axios from 'axios';
+import { JSDOM } from 'jsdom';
+
+import { cleanString } from '../utils';
+import { BaseLoader } from './BaseLoader';
+
+class WebPageLoader extends BaseLoader {
+  // eslint-disable-next-line class-methods-use-this
+  async loadData(url: string) {
+    const response = await axios.get(url);
+    const html = response.data;
+    const dom = new JSDOM(html);
+    const { document } = dom.window;
+    const unwantedTags = [
+      'nav',
+      'aside',
+      'form',
+      'header',
+      'noscript',
+      'svg',
+      'canvas',
+      'footer',
+      'script',
+      'style',
+    ];
+    unwantedTags.forEach((tagName) => {
+      const elements = document.getElementsByTagName(tagName);
+      Array.from(elements).forEach((element) => {
+        // eslint-disable-next-line no-param-reassign
+        (element as HTMLElement).textContent = ' ';
+      });
+    });
+
+    const output = [];
+    let content = document.body.textContent;
+    if (!content) {
+      throw new Error('Web page content is empty.');
+    }
+    content = cleanString(content);
+    const metaData = {
+      url,
+    };
+    output.push({
+      content,
+      metaData,
+    });
+    return output;
+  }
+}
+
+export { WebPageLoader };

embedchain-js/embedchain/loaders/index.ts

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+import { BaseLoader } from './BaseLoader';
+import { LocalQnaPairLoader } from './LocalQnaPair';
+import { PdfFileLoader } from './PdfFile';
+import { WebPageLoader } from './WebPage';
+
+export { BaseLoader, LocalQnaPairLoader, PdfFileLoader, WebPageLoader };