Scraping Craigslist Listings with Objective-C

Oct 1, 2023 · 4 min read

This article explains how to scrape Craigslist apartment listings using Objective-C and the HTMLParser library. We'll go through each part of the code.

First import the HTMLParser header:

#import "HTMLParser.h"

HTMLParser allows parsing HTML documents.

Set the URL to scrape:

NSURL* url = [NSURL URLWithString:@"<https://sfbay.craigslist.org/search/apa>"];

Use NSURLSession to get the HTML content:

NSURLSessionDataTask* task = [[NSURLSession sharedSession] dataTaskWithURL:url completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {

  NSString* html = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

}];
[task resume];

Parse the HTML:

HTMLParser* parser = [[HTMLParser alloc] initWithData:html];
HTMLNode* body = [parser body];

If you check the source code of Craigslist listings you can see that the listings area code looks something like this…

You can see the code block that generates the listing…

<li class="cl-static-search-result" title="Situated in Sunnyvale!, Recycling Center, 1/BD">
            <a href="https://sfbay.craigslist.org/sby/apa/d/santa-clara-situated-in-sunnyvale/7666802370.html">
                <div class="title">Situated in Sunnyvale!, Recycling Center, 1/BD</div>

                <div class="details">
                    <div class="price">$2,150</div>
                    <div class="location">
                        sunnyvale
                    </div>
                </div>
            </a>
        </li>

its encapsulated in the cl-static-search-result class. We also need to get the title class div and the price and location class divs to get all the data

Find all listing nodes:

NSArray* listings = [body findAll:@[@"li[contains(@class,'cl-static-search-result')]"]];

Loop through listings and extract info:

for (HTMLNode* listing in listings) {

  NSString* title = [listing find:@"div.title"].text;
  NSString* price = [listing find:@"div.price"].text;
  NSString* location = [listing find:@"div.location"].text;

  NSString* link = [[listing find:@"a"] attribute:@"href"];

  NSLog(@"%@ %@ %@ %@", title, price, location, link);

}

The full Objective-C code:

#import "HTMLParser.h"

NSURL* url = [NSURL URLWithString:@"<https://sfbay.craigslist.org/search/apa>"];

NSURLSessionDataTask* task = [[NSURLSession sharedSession] dataTaskWithURL:url completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {

  NSString* html = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

  HTMLParser* parser = [[HTMLParser alloc] initWithData:html];
  HTMLNode* body = [parser body];

  NSArray* listings = [body findAll:@[@"li[contains(@class,'cl-static-search-result')]"]];

  for (HTMLNode* listing in listings) {

    NSString* title = [listing find:@"div.title"].text;
    NSString* price = [listing find:@"div.price"].text;
    NSString* location = [listing find:@"div.location"].text;

    NSString* link = [[listing find:@"a"] attribute:@"href"];

    NSLog(@"%@ %@ %@ %@", title, price, location, link);

  }

}];

[task resume];

This walks through scraping Craigslist in Objective-C.

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