epubjs/lib/epub/navigation.js

Parse and Render Epubs

import _classCallCheck from "babel-runtime/helpers/classCallCheck";
import _createClass from "babel-runtime/helpers/createClass";
import { qs, qsa, querySelectorByType, filterChildren, getParentByTagName, uuid } from "../utils/core";

/**
 * Navigation Parser
 * @param {document} xml navigation html / xhtml / ncx
 */

var Navigation = function () {
	function Navigation(xml, url) {
		_classCallCheck(this, Navigation);

		this.toc = [];
		this.tocByHref = {};
		this.tocById = {};

		this.landmarks = [];
		this.landmarksByType = {};

		this.length = 0;

		this.url = url || "";

		if (xml) {
			this.parse(xml);
		}
	}

	/**
  * Parse out the navigation items
  * @param {document} xml navigation html / xhtml / ncx
  */


	_createClass(Navigation, [{
		key: "parse",
		value: function parse(xml) {
			var isXml = xml.nodeType;
			var html = void 0;
			var ncx = void 0;

			if (isXml) {
				html = qs(xml, "html");
				ncx = qs(xml, "ncx");
			}

			if (!isXml) {
				this.toc = this.load(xml);
			} else if (html) {
				this.toc = this.parseNav(xml);
				this.landmarks = this.parseLandmarks(xml);
			} else if (ncx) {
				this.toc = this.parseNcx(xml);
			}

			this.length = 0;

			this.unpack(this.toc);
		}

		/**
   * Unpack navigation items
   * @private
   * @param  {array} toc
   */

	}, {
		key: "unpack",
		value: function unpack(toc) {
			var item;
			var href;

			for (var i = 0; i < toc.length; i++) {
				item = toc[i];
				href = item.href;

				if (item.href) {
					this.tocByHref[href] = i;
				}

				if (item.id) {
					this.tocById[href] = i;
				}

				this.length++;

				if (item.children.length) {
					this.unpack(item.children);
				}
			}
		}

		/**
   * Get an item from the navigation
   * @param  {string} target
   * @return {object} navItems
   */

	}, {
		key: "get",
		value: function get(target) {
			var index;

			if (!target) {
				return this.toc;
			}

			if (target.indexOf("#") === 0) {
				index = this.tocById[target.substring(1)];
			} else if (target in this.tocByHref) {
				index = this.tocByHref[target];
			}

			return this.toc[index];
		}

		/**
   * Get a landmark by type
   * List of types: https://idpf.github.io/epub-vocabs/structure/
   * @param  {string} type
   * @return {object} landmarkItems
   */

	}, {
		key: "landmark",
		value: function landmark(type) {
			var index;

			if (!type) {
				return this.landmarks;
			}

			index = this.landmarksByType[type];

			return this.landmarks[index];
		}

		/**
   * Parse toc from a Epub > 3.0 Nav
   * @private
   * @param  {document} navHtml
   * @return {array} navigation list
   */

	}, {
		key: "parseNav",
		value: function parseNav(navHtml) {
			var navElement = querySelectorByType(navHtml, "nav", "toc");
			var navItems = navElement ? qsa(navElement, "li") : [];
			var length = navItems.length;
			var i;
			var toc = {};
			var list = [];
			var item, parent;

			if (!navItems || length === 0) return list;

			for (i = 0; i < length; ++i) {
				item = this.navItem(navItems[i]);
				if (item) {
					toc[item.id] = item;
					if (!item.parentIndex) {
						list.push(item);
					} else {
						parent = toc[item.parent];
						parent.children.push(item);
					}
				}
			}

			return list;
		}

		/**
   * Create a navItem
   * @private
   * @param  {element} item
   * @return {object} navItem
   */

	}, {
		key: "navItem",
		value: function navItem(item) {
			var id = item.getAttribute("id") || undefined;
			var content = filterChildren(item, "a", true);

			if (!content) {
				return;
			}

			if (!id) {
				id = 'epubjs-autogen-toc-id-' + uuid();
				item.setAttribute('id', id);
			}

			var href = content.getAttribute("href") || "";
			var title = content.textContent || "";
			var children = [];
			var parentItem = getParentByTagName(item, "li");
			var parent = void 0;

			var split = href.split("#");
			if (split[0] === "") {
				href = this.url + href;
			}

			if (parentItem) {
				parent = parentItem.getAttribute("id");
			}

			while (!parent && parentItem) {
				parentItem = getParentByTagName(parentItem, "li");
				if (parentItem) {
					parent = parentItem.getAttribute("id");
				}
			}

			return {
				id: id,
				href: href,
				title: title,
				children: children,
				parent: parent
			};
		}

		/**
   * Parse landmarks from a Epub > 3.0 Nav
   * @private
   * @param  {document} navHtml
   * @return {array} landmarks list
   */

	}, {
		key: "parseLandmarks",
		value: function parseLandmarks(navHtml) {
			var navElement = querySelectorByType(navHtml, "nav", "landmarks");
			var navItems = navElement ? qsa(navElement, "li") : [];
			var length = navItems.length;
			var i;
			var list = [];
			var item;

			if (!navItems || length === 0) return list;

			for (i = 0; i < length; ++i) {
				item = this.landmarkItem(navItems[i]);
				if (item) {
					list.push(item);
					this.landmarksByType[item.type] = i;
				}
			}

			return list;
		}

		/**
   * Create a landmarkItem
   * @private
   * @param  {element} item
   * @return {object} landmarkItem
   */

	}, {
		key: "landmarkItem",
		value: function landmarkItem(item) {
			var content = filterChildren(item, "a", true);

			if (!content) {
				return;
			}

			var type = content.getAttributeNS("http://www.idpf.org/2007/ops", "type") || undefined;
			var href = content.getAttribute("href") || "";
			var title = content.textContent || "";

			var split = href.split("#");
			if (split[0] === "") {
				href = this.url + href;
			}

			return {
				href: href,
				title: title,
				type: type
			};
		}

		/**
   * Parse from a Epub > 3.0 NC
   * @private
   * @param  {document} navHtml
   * @return {array} navigation list
   */

	}, {
		key: "parseNcx",
		value: function parseNcx(tocXml) {
			var navPoints = qsa(tocXml, "navPoint");
			var length = navPoints.length;
			var i;
			var toc = {};
			var list = [];
			var item, parent;

			if (!navPoints || length === 0) return list;

			for (i = 0; i < length; ++i) {
				item = this.ncxItem(navPoints[i]);
				toc[item.id] = item;
				if (!item.parent) {
					list.push(item);
				} else {
					parent = toc[item.parent];
					parent.children.push(item);
				}
			}

			return list;
		}

		/**
   * Create a ncxItem
   * @private
   * @param  {element} item
   * @return {object} ncxItem
   */

	}, {
		key: "ncxItem",
		value: function ncxItem(item) {
			var id = item.getAttribute("id") || false,
			    content = qs(item, "content"),
			    href = content.getAttribute("src"),
			    navLabel = qs(item, "navLabel"),
			    title = navLabel.textContent ? navLabel.textContent : "",
			    children = [],
			    parentNode = item.parentNode,
			    parent;

			if (parentNode && parentNode.nodeName === "navPoint") {
				parent = parentNode.getAttribute("id");
			}

			if (!id) {
				id = 'epubjs-autogen-toc-id-' + uuid();
				item.setAttribute('id', id);
			}

			return {
				id: id,
				href: href,
				title: title,
				children: children,
				parent: parent
			};
		}

		/**
   * Load Spine Items
   * @param  {object} json the items to be loaded
   */

	}, {
		key: "load",
		value: function load(json) {
			var _this = this;

			return json.map(function (item) {
				if (item.children) {
					item.children = _this.load(item.children);
				}
				return item;
			});
		}

		/**
   * forEach pass through
   * @param  {Function} fn function to run on each item
   * @return {method} forEach loop
   */

	}, {
		key: "forEach",
		value: function forEach(fn) {
			return this.toc.forEach(fn);
		}

		/**
   * Get an Array of all Table of Contents Items
   */

	}, {
		key: "getTocArray",
		value: function getTocArray(resolver) {
			return this.toc.map(function (item) {
				var url = resolver ? resolver(item.href) : item.href;

				var obj = {
					href: url,
					title: item.title
				};

				if (item.children.length) {
					obj.children = item.children;
				}

				return obj;
			});
		}

		/**
   * Get an Array of all landmarks
   */

	}, {
		key: "getLandmarksArray",
		value: function getLandmarksArray(resolver) {
			return this.landmarks.map(function (item) {
				var url = resolver ? resolver(item.href) : item.href;

				var obj = {
					href: url,
					title: item.title,
					type: item.type
				};

				return obj;
			});
		}
	}]);

	return Navigation;
}();

export default Navigation;