JSON Feed Model

JSON Feed Model provides types which can be used to manipulate JSON Feed data.

The crate is basically a newtype wrapper around Serde JSON's Map type and provides methods to JSON Feed properties.

• Latest API Documentation

Installation

By default, features which depend on the Rust std library are included.

[dependencies]
json-feed-model = "0.1.1"

Alloc Only

If the host environment has an allocator but does not have access to the Rust std library:

[dependencies]
json-feed-model = { version = "0.1.1", default-features = false, features = ["alloc"]}

Examples

The following example shows how to read properties.

use json_feed_model::{Feed, ItemRef, Version};

let json = serde_json::json!({
    "version": "https://jsonfeed.org/version/1.1",
    "title": "Lorem ipsum dolor sit amet.",
    "home_page_url": "https://example.org/",
    "feed_url": "https://example.org/feed.json",
    "items": [
        {
            "id": "cd7f0673-8e81-4e13-b273-4bd1b83967d0",
            "content_text": "Aenean tristique dictum mauris, et.",
            "url": "https://example.org/aenean-tristique"
        },
        {
            "id": "2bcb497d-c40b-4493-b5ae-bc63c74b48fa",
            "content_html": "Vestibulum non magna vitae tortor.",
            "url": "https://example.org/vestibulum-non"
        }
    ]
});

let feed = json_feed_model::from_value(json)?;

assert!(feed.is_valid(&Version::Version1_1));

assert_eq!(feed.version()?, Some(json_feed_model::VERSION_1_1));
assert_eq!(feed.title()?, Some("Lorem ipsum dolor sit amet."));
assert_eq!(feed.home_page_url()?, Some("https://example.org/"));
assert_eq!(feed.feed_url()?, Some("https://example.org/feed.json"));

let items: Option<Vec<ItemRef>> = feed.items()?;
assert!(items.is_some());
let items: Vec<ItemRef> = items.unwrap();
assert_eq!(items.len(), 2);

assert_eq!(items[0].id()?, Some("cd7f0673-8e81-4e13-b273-4bd1b83967d0"));
assert_eq!(
    items[0].content_text()?,
    Some("Aenean tristique dictum mauris, et.")
);
assert_eq!(
    items[0].url()?,
    Some("https://example.org/aenean-tristique")
);

assert_eq!(items[1].id()?, Some("2bcb497d-c40b-4493-b5ae-bc63c74b48fa"));
assert_eq!(
    items[1].content_html()?,
    Some("Vestibulum non magna vitae tortor.")
);
assert_eq!(items[1].url()?, Some("https://example.org/vestibulum-non"));

Custom Extension

The following example uses a custom trait to write and then read a custom extension. It also shows a simple way to use serde_json to write the JSON Feed. See serde_json for other serialization methods.

use json_feed_model::{Feed, Item, Version};
use serde_json::Value;

trait ExampleExtension {
    fn example(&self) -> Result<Option<&str>, json_feed_model::Error>;

    fn set_example<T>(&mut self, value: T) -> Option<Value>
    where
        T: ToString;
}

impl ExampleExtension for Feed {
    fn example(&self) -> Result<Option<&str>, json_feed_model::Error> {
        self.as_map().get("_example").map_or_else(
            || Ok(None),
            |value| match value {
                Value::String(s) => Ok(Some(s.as_str())),
                _ => Err(json_feed_model::Error::UnexpectedType),
            },
        )
    }

    fn set_example<T>(&mut self, value: T) -> Option<Value>
    where
        T: ToString,
    {
        self.as_map_mut()
            .insert(String::from("_example"), Value::String(value.to_string()))
    }
}

let mut feed = Feed::new();
feed.set_version(Version::Version1_1);
feed.set_title("Lorem ipsum dolor sit amet.");

feed.set_example("123456");

let mut item = Item::new();
item.set_id("2bcb497d-c40b-4493-b5ae-bc63c74b48fa");
item.set_content_text("Vestibulum non magna vitae tortor.");
item.set_url("https://example.org/vestibulum-non");

feed.set_items(vec![item]);

assert!(feed.is_valid(&Version::Version1_1));

let expected_json = serde_json::json!({
    "version": "https://jsonfeed.org/version/1.1",
    "title": "Lorem ipsum dolor sit amet.",
    "_example": "123456",
    "items": [
        {
            "id": "2bcb497d-c40b-4493-b5ae-bc63c74b48fa",
            "content_text": "Vestibulum non magna vitae tortor.",
            "url": "https://example.org/vestibulum-non",
        }
    ]
});
assert_eq!(feed, json_feed_model::from_value(expected_json)?);

assert_eq!(feed.example()?, Some("123456"));

let output = serde_json::to_string(&feed);
assert!(output.is_ok());

License

Licensed under either of Apache License, Version 2.0 or MIT License at your option.

Contributions

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.