src/js/core/page.js
function setState(newState) {
    // API since GitBook v3
    state.page          = newState.page;
    state.file          = newState.file;
    state.gitbook       = newState.gitbook;
    state.config        = newState.config;
    state.basePath      = newState.basePath;
    state.book          = newState.book;

    // Deprecated
    state.$book         = $('.book');
    state.revision      = state.gitbook.time;
    state.level         = state.page.level;
    state.filepath      = state.file.path;
    state.chapterTitle  = state.page.title;
    state.innerLanguage = state.book.language || '';

    // Absolute url to the root of the book (inner book)
    state.root = url.resolve(
        location.protocol+'//'+location.host,
        path.dirname(path.resolve(location.pathname.replace(/\/$/, '/index.html'), state.basePath))
    ).replace(/\/?$/, '/');

    // Absolute root to the language (for multilingual book)
    state.bookRoot = state.innerLanguage? url.resolve(state.root, '..') : state.root;
}
function setState(newState) {
    // API since GitBook v3
    state.page          = newState.page;
    state.file          = newState.file;
    state.gitbook       = newState.gitbook;
    state.config        = newState.config;
    state.basePath      = newState.basePath;
    state.book          = newState.book;

    // Deprecated
    state.$book         = $('.book');
    state.revision      = state.gitbook.time;
    state.level         = state.page.level;
    state.filepath      = state.file.path;
    state.chapterTitle  = state.page.title;
    state.innerLanguage = state.book.language || '';

    // Absolute url to the root of the book (inner book)
    state.root = url.resolve(
        location.protocol+'//'+location.host,
        path.dirname(path.resolve(location.pathname.replace(/\/$/, '/index.html'), state.basePath))
    ).replace(/\/?$/, '/');

    // Absolute root to the language (for multilingual book)
    state.bookRoot = state.innerLanguage? url.resolve(state.root, '..') : state.root;
}
/*
Update current state

data-level="{{ page.level }}"
data-chapter-title="{{ page.title }}"
data-filepath="{{ file.path }}"
data-basepath="{{ './'|resolveFile }}"
data-revision="{{ gitbook.time }}"
data-innerlanguage="{{ innerlanguage }}">