File size: 8,938 Bytes
1b44660
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
import { err, ok } from 'neverthrow';
import { z } from 'zod';
import type { Env } from '../index';
import { parseArticle } from './parsers';
import { tryCatchAsync } from './tryCatchAsync';
import { userAgents } from './utils';

/**
 * Schema for validating responses from the Cloudflare Browser Rendering API
 */
export const articleSchema = z.object({
  status: z.coerce.boolean(),
  errors: z.array(z.object({ code: z.number(), message: z.string() })).optional(),
  result: z.string(),
});

/**
 * Fetches an article using Cloudflare's Browser Rendering API
 *
 * This method simulates a real browser to handle modern websites with complex
 * JavaScript, cookie consent walls, paywalls, and other obstacles that might
 * prevent content scraping with a regular HTTP client.
 *
 * @param env Application environment with Cloudflare credentials
 * @param url URL of the article to fetch
 * @returns Result containing either the parsed article content or an error object
 */
export async function getArticleWithBrowser(env: Env, url: string) {
  const response = await tryCatchAsync(
    fetch(`https://api.cloudflare.com/client/v4/accounts/${env.CLOUDFLARE_ACCOUNT_ID}/browser-rendering/content`, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        Authorization: `Bearer ${env.CLOUDFLARE_API_TOKEN}`,
      },
      body: JSON.stringify({
        url,
        userAgent: userAgents[Math.floor(Math.random() * userAgents.length)],
        setExtraHTTPHeaders: {
          Accept: 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8',
          'Accept-Encoding': 'gzip, deflate, br',
          Connection: 'keep-alive',
          DNT: '1',
          'Accept-Language': 'en-US,en;q=0.5',
          'Sec-Fetch-Dest': 'document',
          'Sec-Fetch-Mode': 'navigate',
          'Sec-Fetch-Site': 'none',
          'Sec-Fetch-User': '?1',
          'Upgrade-Insecure-Requests': '1',
        },
        cookies: [],
        gotoOptions: {
          waitUntil: 'networkidle0',
          timeout: 30000,
          referer: 'https://www.google.com/',
        },
        viewport: {
          width: 390,
          height: 844,
          deviceScaleFactor: 3,
          isMobile: true,
          hasTouch: true,
          isLandscape: false,
        },
        rejectResourceTypes: ['image', 'media', 'font', 'websocket'],
        bestAttempt: true,
        // all of these are very brittle, like all script tag usage
        // this mostly works for now but good to revisit every once in a while
        addScriptTag: [
          // Ensures consistent date formatting by overriding Intl.DateTimeFormat
          // to always use 'en-US' locale regardless of browser settings
          // This prevents inconsistent date parsing across different environments
          {
            content:
              "(() => { Object.defineProperty(Intl, 'DateTimeFormat', { \n    writable: true, \n    value: new Proxy(Intl.DateTimeFormat, { \n      construct: (target, args) => new target('en-US', Object.assign({}, args[1])) \n    })\n  }); })();",
          },
          // Automatically accepts cookie consent popups by finding buttons that contain
          // 'accept' and 'cookie'/'consent' text, then programmatically clicking the first match
          // This bypasses cookie walls that would otherwise block content access
          {
            content:
              "(() => { const cookieButtons = Array.from(document.querySelectorAll(\'button, a\')).filter(el => el.textContent.toLowerCase().includes(\'accept\') && (el.textContent.toLowerCase().includes(\'cookie\') || el.textContent.toLowerCase().includes(\'consent\'))); if(cookieButtons.length > 0) { cookieButtons[0].click(); } })();",
          },
          // Circumvents paywalls by:
          // 1. Removing elements with paywall/subscribe identifiers in id/class
          // 2. Removing modal overlays and fixed position barriers
          // 3. Restoring normal page scroll behavior
          // This targets common paywall implementations across various sites
          {
            content:
              "(() => { const paywallElements = Array.from(document.querySelectorAll(\'div, section\')).filter(el => el.id.toLowerCase().includes(\'paywall\') || el.className.toLowerCase().includes(\'paywall\') || el.id.toLowerCase().includes(\'subscribe\') || el.className.toLowerCase().includes(\'subscribe\')); paywallElements.forEach(el => el.remove()); document.querySelectorAll(\'.modal, .modal-backdrop, body > div[style*=\"position: fixed\"]\').forEach(el => el.remove()); document.body.style.overflow = \'auto\'; })();",
          },
          // Cleans up the DOM by removing non-content elements that interfere with article parsing:
          // - Scripts, styles, iframes that might contain tracking or ads
          // - Ad containers and advertisement blocks
          // - Social media widgets and sharing buttons
          // - Comments sections, navbars, headers, footers (except those within articles)
          // - Various UI elements not relevant to the core article content
          {
            content:
              '(() => { document.querySelectorAll(\'script, style, iframe, .ad, .ads, .advertisement, [class*="social"], [id*="social"], .share, .comments, aside, nav, header:not(article header), footer:not(article footer), [role="complementary"], [role="banner"], [role="navigation"], form, .related, .recommended, .newsletter, .subscription\').forEach(el => el.remove()); })();',
          },
          // Simplifies the DOM by stripping all HTML attributes except essential ones:
          // - href: preserves links
          // - src: maintains images and embedded content
          // - alt: keeps accessibility text for images
          // - title: retains tooltip text
          // This reduces noise and potential tracking parameters in the parsed content
          {
            content:
              "(() => { const keepAttributes = [\'href\', \'src\', \'alt\', \'title\']; document.querySelectorAll(\'*\').forEach(el => { [...el.attributes].forEach(attr => { if (!keepAttributes.includes(attr.name.toLowerCase())) { el.removeAttribute(attr.name); }}); }); })();",
          },
          // Recursively removes empty elements to clean up the DOM structure
          // Continues removing elements until no more empty ones are found
          // This eliminates spacing artifacts and layout containers that serve no content purpose
          {
            content:
              "(() => { function removeEmpty() { let removed = 0; document.querySelectorAll(\'div, span, p, section, article\').forEach(el => { if (!el.hasChildNodes() || el.textContent.trim() === \'\') { el.remove(); removed++; } }); return removed; } let pass; do { pass = removeEmpty(); } while(pass > 0); })();",
          },
          // Removes simple meta tags that provide minimal information value
          // Meta tags with only one attribute are typically not useful for content analysis
          // This helps reduce noise in the document head
          {
            content:
              "(() => { document.querySelectorAll(\'meta\').forEach(meta => { if (meta.attributes.length <= 1) { meta.remove(); } }); })();",
          },
        ],
        waitForSelector: {
          selector: 'article, .article, .content, .post, #article, main',
          timeout: 5000,
        },
      }),
    })
  );
  if (response.isErr()) {
    return err({ type: 'FETCH_ERROR', error: response.error });
  }

  const parsedPageContent = articleSchema.safeParse(await response.value.json());
  if (parsedPageContent.success === false) {
    return err({ type: 'VALIDATION_ERROR', error: parsedPageContent.error });
  }

  const articleResult = parseArticle({ html: parsedPageContent.data.result });
  if (articleResult.isErr()) {
    return err({ type: 'PARSE_ERROR', error: articleResult.error });
  }

  return ok(articleResult.value);
}

/**
 * Fetches an article using a simple HTTP request
 *
 * This is a lighter-weight alternative to browser rendering that works for
 * simpler websites that don't rely heavily on client-side JavaScript for content.
 *
 * @param url URL of the article to fetch
 * @returns Result containing either the parsed article content or an error object
 */
export async function getArticleWithFetch(url: string) {
  const response = await tryCatchAsync(
    fetch(url, {
      method: 'GET',
      headers: {
        'User-Agent': userAgents[Math.floor(Math.random() * userAgents.length)],
        Referer: 'https://www.google.com/',
      },
    })
  );
  if (response.isErr()) {
    return err({ type: 'FETCH_ERROR', error: response.error });
  }

  const articleResult = parseArticle({ html: await response.value.text() });
  if (articleResult.isErr()) {
    return err({ type: 'PARSE_ERROR', error: articleResult.error });
  }

  return ok(articleResult.value);
}