print-tree-actions.rs

// Copyright 2014 The html5ever Project Developers. See the
// COPYRIGHT file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

extern crate string_cache;
extern crate tendril;
extern crate html5ever;

use std::io;
use std::default::Default;
use std::collections::HashMap;
use std::borrow::Cow;
use string_cache::QualName;

use tendril::{ByteTendril, StrTendril, ReadExt};

use html5ever::{parse_to, one_input};
use html5ever::tokenizer::Attribute;
use html5ever::tree_builder::{TreeSink, QuirksMode, NodeOrText, AppendNode, AppendText};

struct Sink {
    next_id: usize,
    names: HashMap<usize, QualName>,
}

impl Sink {
    fn get_id(&mut self) -> usize {
        let id = self.next_id;
        self.next_id += 1;
        id
    }
}

impl TreeSink for Sink {
    type Handle = usize;

    fn parse_error(&mut self, msg: Cow<'static, str>) {
        println!("Parse error: {}", msg);
    }

    fn get_document(&mut self) -> usize {
        0
    }

    fn set_quirks_mode(&mut self, mode: QuirksMode) {
        println!("Set quirks mode to {:?}", mode);
    }

    fn same_node(&self, x: usize, y: usize) -> bool {
        x == y
    }

    fn elem_name(&self, target: usize) -> QualName {
        self.names.get(&target).expect("not an element").clone()
    }

    fn create_element(&mut self, name: QualName, _attrs: Vec<Attribute>) -> usize {
        let id = self.get_id();
        println!("Created {:?} as {}", name, id);
        self.names.insert(id, name);
        id
    }

    fn create_comment(&mut self, text: StrTendril) -> usize {
        let id = self.get_id();
        println!("Created comment \"{}\" as {}", escape_default(&text), id);
        id
    }

    fn append(&mut self, parent: usize, child: NodeOrText<usize>) {
        match child {
            AppendNode(n)
                => println!("Append node {} to {}", n, parent),
            AppendText(t)
                => println!("Append text to {}: \"{}\"", parent, escape_default(&t)),
        }
    }

    fn append_before_sibling(&mut self,
            sibling: usize,
            new_node: NodeOrText<usize>) -> Result<(), NodeOrText<usize>> {
        match new_node {
            AppendNode(n)
                => println!("Append node {} before {}", n, sibling),
            AppendText(t)
                => println!("Append text before {}: \"{}\"", sibling, escape_default(&t)),
        }

        // `sibling` will have a parent unless a script moved it, and we're
        // not running scripts.  Therefore we can aways return `Ok(())`.
        Ok(())
    }

    fn append_doctype_to_document(&mut self,
                                  name: StrTendril,
                                  public_id: StrTendril,
                                  system_id: StrTendril) {
        println!("Append doctype: {} {} {}", name, public_id, system_id);
    }

    fn add_attrs_if_missing(&mut self, target: usize, attrs: Vec<Attribute>) {
        println!("Add missing attributes to {}:", target);
        for attr in attrs.into_iter() {
            println!("    {:?} = {}", attr.name, attr.value);
        }
    }

    fn remove_from_parent(&mut self, target: usize) {
        println!("Remove {} from parent", target);
    }

    fn reparent_children(&mut self, node: usize, new_parent: usize) {
        println!("Move children from {} to {}", node, new_parent);
    }

    fn mark_script_already_started(&mut self, node: usize) {
        println!("Mark script {} as already started", node);
    }
}

// Copy of str::escape_default from std, which is currently unstable
pub fn escape_default(s: &str) -> String {
    s.chars().flat_map(|c| c.escape_default()).collect()
}

fn main() {
    let sink = Sink {
        next_id: 1,
        names: HashMap::new(),
    };

    let mut input = ByteTendril::new();
    io::stdin().read_to_tendril(&mut input).unwrap();
    let input = input.try_reinterpret().unwrap();
    parse_to(sink, one_input(input), Default::default());
}