Function parse_url 

pub fn parse_url(
    url: &str,
    etag: Option<&str>,
    modified: Option<&str>,
    user_agent: Option<&str>,
) -> Result<ParsedFeed>

Parse feed from HTTP/HTTPS URL

Fetches the feed from the given URL and parses it. Supports conditional GET using ETag and Last-Modified headers for bandwidth-efficient caching.

Arguments

• url - HTTP or HTTPS URL to fetch
• etag - Optional ETag from previous fetch for conditional GET
• modified - Optional Last-Modified timestamp from previous fetch
• user_agent - Optional custom User-Agent header

Returns

Returns a ParsedFeed with HTTP metadata fields populated:

• status: HTTP status code (200, 304, etc.)
• href: Final URL after redirects
• etag: ETag header value (for next request)
• modified: Last-Modified header value (for next request)
• headers: Full HTTP response headers

On 304 Not Modified, returns a feed with empty entries but status=304.

Errors

Returns FeedError::Http if:

• Network error occurs
• URL is invalid
• HTTP status is 4xx or 5xx (except 304)

Examples

use feedparser_rs::parse_url;

// First fetch
let feed = parse_url("https://example.com/feed.xml", None, None, None).unwrap();
println!("Title: {:?}", feed.feed.title);
println!("ETag: {:?}", feed.etag);

// Subsequent fetch with caching
let feed2 = parse_url(
    "https://example.com/feed.xml",
    feed.etag.as_deref(),
    feed.modified.as_deref(),
    None
).unwrap();

if feed2.status == Some(304) {
    println!("Feed not modified, use cached version");
}