Kanna is a Swift library used for parsing XML and HTML documents. When dealing with internationalized websites that have content in multiple languages, Kanna behaves similarly to other HTML parsing libraries, in that it does not inherently handle language-specific logic but rather parses the document structure as provided.
Here are some considerations and steps you can take when using Kanna to handle internationalized websites:
1. Encoding
Make sure you correctly handle the encoding of the webpage. Kanna should automatically handle different encodings as long as the HTML document specifies its encoding properly with a <meta> tag, for example:
<meta charset="UTF-8">
2. Identifying Language
Look for the lang attribute in the <html> tag to identify the language of the document:
import Kanna
if let doc = try? HTML(url: URL(string: "http://example.com")!, encoding: .utf8) {
if let language = doc.at_xpath("//html")?["lang"] {
print("Language: \(language)")
}
}
3. Targeting Content Based on Language
When scraping content from a specific language version of a website, you might need to target elements with language-specific selectors, like classes or ids that include language codes:
// Assume the German content is marked with a class 'de'
if let germanContent = doc.at_css(".de") {
// Process the German content
}
4. Handling Language Switching
If the website uses a specific mechanism for switching languages (like query parameters, different URLs, or cookies), you'll need to adjust your HTTP requests accordingly:
// Example: Using URL with language query parameter
let germanURL = URL(string: "http://example.com?lang=de")!
// Example: Using a URL path segment for language
let germanURL = URL(string: "http://example.com/de/")!
5. Text Extraction and Translation
If you need to extract text and potentially translate it, you can do so after parsing the document:
// Extract all text nodes
for textNode in doc.xpath("//text()") {
let text = textNode.text?.trimmingCharacters(in: .whitespacesAndNewlines)
// Do something with the text, like translation
}
6. Dealing with Dynamic Content
For websites that load content dynamically based on language preferences (e.g., via JavaScript), Kanna alone may not be sufficient, as it doesn't execute JavaScript. In such cases, you might need to use additional tools like Selenium with WebDriver for Swift, or you might need to look at the network requests to directly access the data source if it's loaded via AJAX.
Remember to always respect the website's robots.txt file and terms of service when scraping content, and be mindful of the legal and ethical implications of web scraping.
