| gitbook.require(["gitbook", "lodash", "jQuery"], function(gitbook, _, $) { |
| var index = null; |
| var fuse = null; |
| var _search = {engine: 'lunr', opts: {}}; |
| var $searchInput, $searchLabel, $searchForm; |
| var $highlighted = [], hi, hiOpts = { className: 'search-highlight' }; |
| var collapse = false, toc_visible = []; |
| |
| function init(config) { |
| // Instantiate search settings |
| _search = gitbook.storage.get("search", { |
| engine: config.search.engine || 'lunr', |
| opts: config.search.options || {}, |
| }); |
| }; |
| |
| // Save current search settings |
| function saveSearchSettings() { |
| gitbook.storage.set("search", _search); |
| } |
| |
| // Use a specific index |
| function loadIndex(data) { |
| // [Yihui] In bookdown, I use a character matrix to store the chapter |
| // content, and the index is dynamically built on the client side. |
| // Gitbook prebuilds the index data instead: https://github.com/GitbookIO/plugin-search |
| // We can certainly do that via R packages V8 and jsonlite, but let's |
| // see how slow it really is before improving it. On the other hand, |
| // lunr cannot handle non-English text very well, e.g. the default |
| // tokenizer cannot deal with Chinese text, so we may want to replace |
| // lunr with a dumb simple text matching approach. |
| if (_search.engine === 'lunr') { |
| index = lunr(function () { |
| this.ref('url'); |
| this.field('title', { boost: 10 }); |
| this.field('body'); |
| }); |
| data.map(function(item) { |
| index.add({ |
| url: item[0], |
| title: item[1], |
| body: item[2] |
| }); |
| }); |
| return; |
| } |
| fuse = new Fuse(data.map((_data => { |
| return { |
| url: _data[0], |
| title: _data[1], |
| body: _data[2] |
| }; |
| })), Object.assign( |
| { |
| includeScore: true, |
| threshold: 0.1, |
| ignoreLocation: true, |
| keys: ["title", "body"] |
| }, |
| _search.opts |
| )); |
| } |
| |
| // Fetch the search index |
| function fetchIndex() { |
| return $.getJSON(gitbook.state.basePath+"/search_index.json") |
| .then(loadIndex); // [Yihui] we need to use this object later |
| } |
| |
| // Search for a term and return results |
| function search(q) { |
| let results = []; |
| switch (_search.engine) { |
| case 'fuse': |
| if (!fuse) return; |
| results = fuse.search(q).map(function(result) { |
| var parts = result.item.url.split('#'); |
| return { |
| path: parts[0], |
| hash: parts[1] |
| }; |
| }); |
| break; |
| case 'lunr': |
| default: |
| if (!index) return; |
| results = _.chain(index.search(q)).map(function(result) { |
| var parts = result.ref.split("#"); |
| return { |
| path: parts[0], |
| hash: parts[1] |
| }; |
| }) |
| .value(); |
| } |
| |
| // [Yihui] Highlight the search keyword on current page |
| $highlighted = $('.page-inner') |
| .unhighlight(hiOpts).highlight(q, hiOpts).find('span.search-highlight'); |
| scrollToHighlighted(0); |
| |
| return results; |
| } |
| |
| // [Yihui] Scroll the chapter body to the i-th highlighted string |
| function scrollToHighlighted(d) { |
| var n = $highlighted.length; |
| hi = hi === undefined ? 0 : hi + d; |
| // navignate to the previous/next page in the search results if reached the top/bottom |
| var b = hi < 0; |
| if (d !== 0 && (b || hi >= n)) { |
| var path = currentPath(), n2 = toc_visible.length; |
| if (n2 === 0) return; |
| for (var i = b ? 0 : n2; (b && i < n2) || (!b && i >= 0); i += b ? 1 : -1) { |
| if (toc_visible.eq(i).data('path') === path) break; |
| } |
| i += b ? -1 : 1; |
| if (i < 0) i = n2 - 1; |
| if (i >= n2) i = 0; |
| var lnk = toc_visible.eq(i).find('a[href$=".html"]'); |
| if (lnk.length) lnk[0].click(); |
| return; |
| } |
| if (n === 0) return; |
| var $p = $highlighted.eq(hi); |
| $p[0].scrollIntoView(); |
| $highlighted.css('background-color', ''); |
| // an orange background color on the current item and removed later |
| $p.css('background-color', 'orange'); |
| setTimeout(function() { |
| $p.css('background-color', ''); |
| }, 2000); |
| } |
| |
| function currentPath() { |
| var href = window.location.pathname; |
| href = href.substr(href.lastIndexOf('/') + 1); |
| return href === '' ? 'index.html' : href; |
| } |
| |
| // Create search form |
| function createForm(value) { |
| if ($searchForm) $searchForm.remove(); |
| if ($searchLabel) $searchLabel.remove(); |
| if ($searchInput) $searchInput.remove(); |
| |
| $searchForm = $('<div>', { |
| 'class': 'book-search', |
| 'role': 'search' |
| }); |
| |
| $searchLabel = $('<label>', { |
| 'for': 'search-box', |
| 'aria-hidden': 'false', |
| 'hidden': '' |
| }); |
| |
| $searchInput = $('<input>', { |
| 'id': 'search-box', |
| 'type': 'search', |
| 'class': 'form-control', |
| 'val': value, |
| 'placeholder': 'Type to search (Enter for navigation)', |
| 'title': 'Use Enter or the <Down> key to navigate to the next match, or the <Up> key to the previous match' |
| }); |
| |
| $searchLabel.append("Type to search"); |
| $searchLabel.appendTo($searchForm); |
| $searchInput.appendTo($searchForm); |
| $searchForm.prependTo(gitbook.state.$book.find('.book-summary')); |
| } |
| |
| // Return true if search is open |
| function isSearchOpen() { |
| return gitbook.state.$book.hasClass("with-search"); |
| } |
| |
| // Toggle the search |
| function toggleSearch(_state) { |
| if (isSearchOpen() === _state) return; |
| if (!$searchInput) return; |
| |
| gitbook.state.$book.toggleClass("with-search", _state); |
| |
| // If search bar is open: focus input |
| if (isSearchOpen()) { |
| gitbook.sidebar.toggle(true); |
| $searchInput.focus(); |
| } else { |
| $searchInput.blur(); |
| $searchInput.val(""); |
| gitbook.storage.remove("keyword"); |
| gitbook.sidebar.filter(null); |
| $('.page-inner').unhighlight(hiOpts); |
| } |
| } |
| |
| function sidebarFilter(results) { |
| gitbook.sidebar.filter(_.pluck(results, "path")); |
| toc_visible = $('ul.summary').find('li:visible'); |
| } |
| |
| // Recover current search when page changed |
| function recoverSearch() { |
| var keyword = gitbook.storage.get("keyword", ""); |
| |
| createForm(keyword); |
| |
| if (keyword.length > 0) { |
| if(!isSearchOpen()) { |
| toggleSearch(true); // [Yihui] open the search box |
| } |
| sidebarFilter(search(keyword)); |
| } |
| } |
| |
| |
| gitbook.events.bind("start", function(e, config) { |
| // [Yihui] disable search |
| if (config.search === false) return; |
| init(config); |
| collapse = !config.toc || config.toc.collapse === 'section' || |
| config.toc.collapse === 'subsection'; |
| |
| // Pre-fetch search index and create the form |
| fetchIndex() |
| // [Yihui] recover search after the page is loaded |
| .then(recoverSearch); |
| |
| |
| // Type in search bar |
| $(document).on("keyup", ".book-search input", function(e) { |
| var key = (e.keyCode ? e.keyCode : e.which); |
| // [Yihui] Escape -> close search box; Up/Down/Enter: previous/next highlighted |
| if (key == 27) { |
| e.preventDefault(); |
| toggleSearch(false); |
| } else if (key == 38) { |
| scrollToHighlighted(-1); |
| } else if (key == 40 || key == 13) { |
| scrollToHighlighted(1); |
| } |
| }).on("input", ".book-search input", function(e) { |
| var q = $(this).val().trim(); |
| if (q.length === 0) { |
| gitbook.sidebar.filter(null); |
| gitbook.storage.remove("keyword"); |
| $('.page-inner').unhighlight(hiOpts); |
| } else { |
| var results = search(q); |
| sidebarFilter(results); |
| gitbook.storage.set("keyword", q); |
| } |
| }); |
| |
| // Create the toggle search button |
| gitbook.toolbar.createButton({ |
| icon: 'fa fa-search', |
| label: 'Search', |
| position: 'left', |
| onClick: toggleSearch |
| }); |
| |
| // Bind keyboard to toggle search |
| gitbook.keyboard.bind(['f'], toggleSearch); |
| }); |
| |
| // [Yihui] do not try to recover search; always start fresh |
| // gitbook.events.bind("page.change", recoverSearch); |
| }); |
