opml/opml_cli/source/main.rs

111 lines
3.0 KiB
Rust
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use std::fs::read_to_string;
use clap::{
crate_authors, crate_description, crate_version, App, Arg, ArgGroup,
};
use opml::{Outline, OPML};
fn main() {
let cli = App::new("OPML CLI")
.about(crate_description!())
.author(crate_authors!())
.version(crate_version!())
.args(&[
// Format flags.
Arg::with_name("json")
.long("json")
.long_help("Output the OPML as JSON.")
.takes_value(false),
Arg::with_name("json pretty")
.long("json-pretty")
.long_help("Output the OPML as pretty-printed JSON.")
.takes_value(false),
Arg::with_name("rss")
.long("rss")
.long_help(
"Only output the outline text and xmlUrl attributes \
when both are present in the outline element.",
)
.takes_value(false),
// Boolean flags.
Arg::with_name("verbose")
.long("verbose")
.long_help("Print extra information while running.")
.takes_value(false),
// Options that are only allowed once.
Arg::with_name("file")
.long("file")
.long_help("The OPML file to parse.")
.required(true)
.short("f")
.takes_value(true),
])
.group(
ArgGroup::with_name("format")
.args(&["json", "json pretty", "rss"])
.required(true),
)
.get_matches();
// Extract format flags.
let json = cli.is_present("json");
let json_pretty = cli.is_present("json pretty");
let rss = cli.is_present("rss");
// Extract boolean flags.
let verbose = cli.is_present("verbose");
// Extract the various options.
let file = cli.value_of("file").unwrap();
// Read the file to string.
let xml = read_to_string(file).expect("Failed to read OPML file");
// Parse the OPML from the read file.
let opml = OPML::new(&xml).expect("Failed to parse OPML file");
if rss {
// Get all the outlines from the OPML document.
let outlines = extract_all_outlines(&opml.body.outlines);
// Print out the text and xmlUrl attributes when possible.
for outline in outlines {
if let Some(xml_url) = outline.xml_url {
println!("{}", outline.text);
println!("{}", xml_url);
} else if verbose {
println!(
"Skipping \"{}\" because it did not have an xmlUrl attribute.",
outline.text
);
}
}
} else if json {
println!(
"{}",
serde_json::to_string(&opml).expect("Failed to convert OPML to JSON")
);
} else if json_pretty {
println!(
"{}",
serde_json::to_string_pretty(&opml)
.expect("Failed to convert OPML to pretty JSON")
);
} else {
unreachable!();
}
}
/// A helper function that takes in `opml::Outline` elements and returns all
/// children it can find in a single `Vec<Outline>`.
pub fn extract_all_outlines(outlines: &[Outline]) -> Vec<Outline> {
let mut accumulator = vec![];
for outline in outlines {
accumulator.push(outline.clone());
accumulator.append(&mut extract_all_outlines(&outline.outlines));
}
accumulator
}