rss 0.5.0

// This file is part of rss.
//
// Copyright © 2015-2017 The rust-syndication Developers
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the MIT License and/or Apache 2.0 License.

use error::Error;
use quick_xml::{Element, Event, XmlWriter};
use quick_xml::error::Error as XmlError;
use std::collections::HashMap;
use toxml::ToXml;

/// Types and functions for
/// [iTunes](https://help.apple.com/itc/podcasts_connect/#/itcb54353390) extensions.
pub mod itunes;

/// Types and functions for [Dublin Core](http://dublincore.org/documents/dces/) extensions.
pub mod dublincore;

/// A map of extension namespace prefixes to local names to elements.
pub type ExtensionMap = HashMap<String, HashMap<String, Vec<Extension>>>;

/// A namespaced extension such as iTunes or Dublin Core.
#[derive(Debug, Default, Clone, PartialEq)]
pub struct Extension {
    /// The qualified name of the extension element.
    name: String,
    /// The content of the extension element.
    value: Option<String>,
    /// The attributes for the extension element.
    attrs: HashMap<String, String>,
    /// The children of the extension element. This is a map of local names to child
    /// elements.
    children: HashMap<String, Vec<Extension>>,
}

impl Extension {
    /// Get the name that exists under `Extension`.
    pub fn name(&self) -> &str {
        self.name.as_str()
    }

    /// Get the value that exists under `Extension`.
    pub fn value(&self) -> Option<&str> {
        self.value.as_ref().map(|s| s.as_str())
    }

    /// Get the attrs that exists under `Extension`.
    pub fn attrs(&self) -> &HashMap<String, String> {
        &self.attrs
    }

    /// Get the children that exists under `Extension`.
    pub fn children(&self) -> &HashMap<String, Vec<Extension>> {
        &self.children
    }
}

impl ToXml for Extension {
    fn to_xml<W: ::std::io::Write>(&self, writer: &mut XmlWriter<W>) -> Result<(), XmlError> {
        let element = Element::new(&self.name);

        writer
            .write(Event::Start({
                                    let mut element = element.clone();
                                    element.extend_attributes(&self.attrs);
                                    element
                                }))?;

        if let Some(value) = self.value.as_ref() {
            writer.write(Event::Text(Element::new(value)))?;
        }

        for extensions in self.children.values() {
            for extension in extensions {
                extension.to_xml(writer)?;
            }
        }

        writer.write(Event::End(element))
    }
}

/// A namespaced extension such as iTunes or Dublin Core.
#[derive(Debug, Default, Clone)]
pub struct ExtensionBuilder {
    /// The qualified name of the extension element.
    name: String,
    /// The content of the extension element.
    value: Option<String>,
    /// The attributes for the extension element.
    attrs: HashMap<String, String>,
    /// The children of the extension element. This is a map of local names to child
    /// elements.
    children: HashMap<String, Vec<Extension>>,
}

impl ExtensionBuilder {
    // Construct a new `DublinCoreExtensionBuilder` and return default values.
    ///
    /// # Examples
    ///
    /// ```
    /// use rss::extension::ExtensionBuilder;
    ///
    /// let extension_builder = ExtensionBuilder::new();
    /// ```
    pub fn new() -> ExtensionBuilder {
        ExtensionBuilder::default()
    }

    /// Get the name that exists under `Extension`.
    pub fn name(mut self, name: &str) -> ExtensionBuilder {
        self.name = name.to_string();
        self
    }

    /// Get the value that exists under `Extension`.
    pub fn value(mut self, value: Option<String>) -> ExtensionBuilder {
        self.value = value;
        self
    }

    /// Get the attrs that exists under `Extension`.
    pub fn attrs(mut self, attrs: HashMap<String, String>) -> ExtensionBuilder {
        self.attrs = attrs;
        self
    }

    /// Get the children that exists under `Extension`.
    pub fn children(mut self, children: HashMap<String, Vec<Extension>>) -> ExtensionBuilder {
        self.children = children;
        self
    }

    /// Construct the `ExtensionBuilder` from the `ExtensionBuilderBuilder`.
    pub fn finalize(self) -> Result<Extension, Error> {
        Ok(Extension {
               name: self.name,
               value: self.value,
               attrs: self.attrs,
               children: self.children,
           })
    }
}

/// Get a reference to the value for the first extension with the specified key.
pub fn get_extension_value<'a>(map: &'a HashMap<String, Vec<Extension>>,
                               key: &str)
                               -> Option<&'a str> {
    map.get(key)
        .and_then(|v| v.first())
        .and_then(|ext| ext.value.as_ref())
        .map(|s| s.as_str())
}

/// Remove and return the value for the first extension with the specified key.
pub fn remove_extension_value(map: &mut HashMap<String, Vec<Extension>>,
                              key: &str)
                              -> Option<String> {
    map.remove(key)
        .map(|mut v| v.remove(0))
        .and_then(|ext| ext.value)
}

/// Get a reference to all values for the extensions with the specified key.
pub fn get_extension_values<'a>(map: &'a HashMap<String, Vec<Extension>>,
                                key: &str)
                                -> Option<Vec<&'a str>> {
    map.get(key)
        .map(|v| {
                 v.iter()
                     .filter_map(|ext| ext.value.as_ref().map(|s| s.as_str()))
                     .collect::<Vec<_>>()
             })
}

/// Remove and return all values for the extensions with the specified key.
pub fn remove_extension_values(map: &mut HashMap<String, Vec<Extension>>,
                               key: &str)
                               -> Option<Vec<String>> {
    map.remove(key)
        .map(|v| {
                 v.into_iter()
                     .filter_map(|ext| ext.value)
                     .collect::<Vec<_>>()
             })
}