Objective-C is a powerful language for web scraping on Apple platforms like iOS and macOS. ChatGPT is an AI assistant that can provide explanations and generate code for scraping tasks. This article covers web scraping in Objective-C with ChatGPT's help.
Setting Up Objective-C for Web Scraping
You'll need Xcode installed, along with these frameworks/libraries:
// Foundation for HTTP requests
#import <Foundation/Foundation.h>
// libxml2 for HTML parsing
#import <libxml/HTMLparser.h>
// CSVParser for CSV parsing
#import "CSVParser.h"
Introduction to Web Scraping in Objective-C
Web scraping involves sending requests to websites and extracting data from the HTML, JSON or XML responses. Useful Objective-C options:
Typical web scraping workflow:
Using ChatGPT for Web Scraping Help
ChatGPT is an AI assistant created by Anthropic to be helpful, harmless, and honest. It can provide explanations and generate code snippets for web scraping:
Getting Explanations
Ask ChatGPT to explain web scraping concepts or specifics:
Generating Code Snippets
Give a description of what you want to scrape and have ChatGPT provide starter Objective-C code:
Validate any code before using.
Improving Prompts
Ask ChatGPT to suggest ways to improve your prompt if it doesn't provide helpful responses.
Asking Follow-up Questions
Chat with ChatGPT to get explanations for any other questions you have.
Explaining Errors
Share any errors and ask ChatGPT to debug and explain the problem.
Web Scraping Example Using ChatGPT
Let's walk through scraping a Wikipedia page with ChatGPT's assistance.
Goal
Extract the chronology table from: https://en.wikipedia.org/wiki/Chronology_of_the_universe
Step 1: Download page
ChatGPT: Objective-C code to download this page:
<https://en.wikipedia.org/wiki/Chronology_of_the_universe>
// ChatGPT provides this code
NSURL *url = [NSURL URLWithString:@"<https://en.wikipedia.org/wiki/Chronology_of_the_universe>"];
NSURLSessionDataTask *task = [[NSURLSession sharedSession] dataTaskWithURL:url completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
// Handle response
}];
[task resume];
Step 2: Inspect HTML, table has class wikitable
Step 3: Extract table data to CSV
ChatGPT: Objective-C code to extract wikitable table to CSV
// ChatGPT provides this code
htmlDocPtr doc = htmlReadMemory(html.UTF8String, html.length, "", NULL, HTML_PARSE_NOBLANKS | HTML_PARSE_NOERROR | HTML_PARSE_NOWARNING | HTML_PARSE_NONET);
xmlNodePtr table = xpath_node(doc, "//table[contains(@class, 'wikitable')]");
// Extract headers
NSArray *headers = //...
// Extract rows
NSArray *rows = //...
// Write to CSV
//...
xmlFreeDoc(doc);
This shows using ChatGPT to get Objective-C scraping code quickly.
Conclusion
Key points:
ChatGPT + Objective-C is great for Apple scraping apps.
However, some limitations:
A more robust solution is using a web scraping API like Proxies API
Proxies API provides:
Easily scrape any site:
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"<https://api.proxiesapi.com/?url=example.com&key=XXX>"]];
// Send request
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