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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