Can I use Kanna to scrape data from APIs or only from HTML content?

Kanna is a Swift library for parsing XML and HTML. It is primarily used for extracting data from the structure of HTML documents or XML feeds. Kanna provides a way to select and manipulate HTML elements by using XPath or CSS selectors, which is particularly useful for scraping content from web pages.

When it comes to APIs, the type of data you're usually dealing with is different. APIs typically return data in a structured format such as JSON or XML, rather than HTML. Since Kanna is designed for HTML and XML parsing, it can be used to parse data from APIs that return XML. However, for APIs that return JSON, Kanna would not be the right tool for the job.

For JSON APIs, you would typically use Swift's built-in capabilities or a library like SwiftyJSON or Codable to parse the JSON data. Here’s how you might use each approach:

Using Swift Codable

Swift's Codable protocol makes it easy to decode JSON into strongly typed Swift objects. Here's an example of how you can use Codable to parse JSON data from an API:

import Foundation

// Define your model that conforms to Codable
struct MyModel: Codable {
    let id: Int
    let name: String
    // Add other properties as needed
}

// Assume `jsonData` is the data you received from the API.
let jsonData = """
{
    "id": 1,
    "name": "Example"
}
""".data(using: .utf8)!

do {
    // Decode the JSON data into your model
    let decodedData = try JSONDecoder().decode(MyModel.self, from: jsonData)
    print(decodedData.name)
} catch {
    print("Error decoding JSON: \(error)")
}

Using SwiftyJSON

SwiftyJSON is a third-party library that simplifies working with JSON data in Swift. Here's an example of how you can use SwiftyJSON to parse JSON from an API:

import SwiftyJSON

// Assume `jsonData` is the data you received from the API.
let jsonData = """
{
    "id": 1,
    "name": "Example"
}
""".data(using: .utf8)!

let json = try! JSON(data: jsonData)

// Access values directly
let id = json["id"].intValue
let name = json["name"].stringValue

print(name)

Using Kanna for XML API

If the API provides data in XML format, you can use Kanna to parse it. Here's an example of how to use Kanna to parse XML:

import Kanna

// Assume `xmlData` is the XML data you received from the API.
let xmlData = """
<response>
    <id>1</id>
    <name>Example</name>
</response>
"""

do {
    // Parse the XML data with Kanna
    let doc = try XML(xml: xmlData, encoding: .utf8)

    // Use XPath or CSS to select elements
    if let id = doc.xpath("//id").first?.text,
       let name = doc.xpath("//name").first?.text {
        print("ID: \(id), Name: \(name)")
    }
} catch {
    print("Error parsing XML: \(error)")
}

To summarize, you can use Kanna to scrape data from APIs that return XML. For APIs that return JSON, you should use Codable or a library like SwiftyJSON to parse the data instead.