Feat homework 10/ Loading CSV Files

lesson_10/libraries/src/loaders/dylan_lafferty_loaders.ts

@@ -0,0 +1,62 @@
+import csv from 'csv-parser';
+import fs from 'fs';
+import { Credit, MediaItem } from '../models/index.js';
+import { Loader } from './loader.js';
+
+export class DylanLaffertysLoader implements Loader {
+  getLoaderName(): string {
+    return 'dylanlafferty';
+  }
+  async loadData(): Promise<MediaItem[]> {
+    const credits = await this.loadCredits(); //loads credits from the csv file
+    const mediaItems = await this.loadMediaItems(); //loads media items from csv file
+
+    //Creates a map where the key is a string and the value is MediaItem Object
+    const mapIndex = new Map<string, MediaItem>();
+
+    //Loops through the CSV file and gets the id of the mediaItem that is specified.
+    for (const mediaItem of mediaItems) {
+      mapIndex.set(mediaItem.getId(), mediaItem);
+
+    }
+
+    for (const credit of credits) {
+      const mediaItem = mapIndex.get(credit.getMediaItemId()); //Finds the media item by getting media ID
+      if (mediaItem) {
+        mediaItem.addCredit(credit);
+      }
+    }
+
+    console.log(
+      `Loaded ${credits.length} credits and ${mediaItems.length} media items`,
+    );
+    //Returns a newly created array by converting the map values
+    return Array.from(mapIndex.values());
+  }
+
+  async loadMediaItems(): Promise<MediaItem[]> {
+    const mediaItem = [];
+    const readable = fs
+      .createReadStream('data/media_items.csv', 'utf-8')
+      .pipe(csv());
+
+    for await (const row of readable) {
+      const { id, title, type, year } = row;
+      mediaItem.push(new MediaItem(id, title, type, year, []));
+    }
+    return mediaItem;
+  }
+
+  async loadCredits(): Promise<Credit[]> {
+    const credits = [];
+    const readable = fs
+      .createReadStream('data/credits.csv', 'utf-8')
+      .pipe(csv());
+    for await (const row of readable) {
+      const { media_item_id, role, name } = row;
+      credits.push(new Credit(media_item_id, name, role));
+    }
+    return credits;
+  }
+}
+//# sourceMappingURL=dylan_lafferty_loaders.js.map

lesson_10/libraries/src/loaders/loaders.module.ts

@@ -1,10 +1,11 @@
 import { Module } from '@nestjs/common';
 
 import { AnthonyMaysLoader } from './anthony_mays_loader.js';
+import { DylanLaffertysLoader } from './dylan_lafferty_loaders.js';
 
 export const Loaders = Symbol.for('Loaders');
 
-const LOADER_PROVIDERS = [AnthonyMaysLoader];
+const LOADER_PROVIDERS = [AnthonyMaysLoader, DylanLaffertysLoader];
 
 @Module({
   providers: [