preact-helmet/lib/Helmet.js

A document head manager for Preact

exports.__esModule = true;

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

var _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; };

var _preact = require("preact");

var _preactSideEffect = require("preact-side-effect");

var _preactSideEffect2 = _interopRequireDefault(_preactSideEffect);

var _deepEqual = require("deep-equal");

var _deepEqual2 = _interopRequireDefault(_deepEqual);

var _objectAssign = require("object-assign");

var _objectAssign2 = _interopRequireDefault(_objectAssign);

var _HelmetConstants = require("./HelmetConstants.js");

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

var HELMET_ATTRIBUTE = "data-preact-helmet";

var encodeSpecialCharacters = function encodeSpecialCharacters(str) {
    return String(str).replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;").replace(/"/g, "&quot;").replace(/'/g, "&#x27;");
};

var getInnermostProperty = function getInnermostProperty(propsList, property) {
    for (var i = propsList.length - 1; i >= 0; i--) {
        var props = propsList[i];

        if (props[property]) {
            return props[property];
        }
    }
    return null;
};

var getTitleFromPropsList = function getTitleFromPropsList(propsList) {
    var innermostTitle = getInnermostProperty(propsList, "title");
    var innermostTemplate = getInnermostProperty(propsList, "titleTemplate");

    if (innermostTemplate && innermostTitle) {
        // use function arg to avoid need to escape $ characters
        return innermostTemplate.replace(/%s/g, function () {
            return innermostTitle;
        });
    }

    var innermostDefaultTitle = getInnermostProperty(propsList, "defaultTitle");

    return innermostTitle || innermostDefaultTitle || "";
};

var getOnChangeClientState = function getOnChangeClientState(propsList) {
    return getInnermostProperty(propsList, "onChangeClientState") || function () {};
};

var getAttributesFromPropsList = function getAttributesFromPropsList(tagType, propsList) {
    return propsList.filter(function (props) {
        return typeof props[tagType] !== "undefined";
    }).map(function (props) {
        return props[tagType];
    }).reduce(function (tagAttrs, current) {
        return _extends({}, tagAttrs, current);
    }, {});
};

var getBaseTagFromPropsList = function getBaseTagFromPropsList(primaryAttributes, propsList) {
    return propsList.filter(function (props) {
        return typeof props[_HelmetConstants.TAG_NAMES.BASE] !== "undefined";
    }).map(function (props) {
        return props[_HelmetConstants.TAG_NAMES.BASE];
    }).reverse().reduce(function (innermostBaseTag, tag) {
        if (!innermostBaseTag.length) {
            var keys = Object.keys(tag);

            for (var i = 0; i < keys.length; i++) {
                var attributeKey = keys[i];
                var lowerCaseAttributeKey = attributeKey.toLowerCase();

                if (primaryAttributes.indexOf(lowerCaseAttributeKey) !== -1 && tag[lowerCaseAttributeKey]) {
                    return innermostBaseTag.concat(tag);
                }
            }
        }

        return innermostBaseTag;
    }, []);
};

var getTagsFromPropsList = function getTagsFromPropsList(tagName, primaryAttributes, propsList) {
    // Calculate list of tags, giving priority innermost component (end of the propslist)
    var approvedSeenTags = {};

    return propsList.filter(function (props) {
        return typeof props[tagName] !== "undefined";
    }).map(function (props) {
        return props[tagName];
    }).reverse().reduce(function (approvedTags, instanceTags) {
        var instanceSeenTags = {};

        instanceTags.filter(function (tag) {
            var primaryAttributeKey = void 0;
            var keys = Object.keys(tag);
            for (var i = 0; i < keys.length; i++) {
                var attributeKey = keys[i];
                var lowerCaseAttributeKey = attributeKey.toLowerCase();

                // Special rule with link tags, since rel and href are both primary tags, rel takes priority
                if (primaryAttributes.indexOf(lowerCaseAttributeKey) !== -1 && !(primaryAttributeKey === _HelmetConstants.TAG_PROPERTIES.REL && tag[primaryAttributeKey].toLowerCase() === "canonical") && !(lowerCaseAttributeKey === _HelmetConstants.TAG_PROPERTIES.REL && tag[lowerCaseAttributeKey].toLowerCase() === "stylesheet")) {
                    primaryAttributeKey = lowerCaseAttributeKey;
                }
                // Special case for innerHTML which doesn't work lowercased
                if (primaryAttributes.indexOf(attributeKey) !== -1 && (attributeKey === _HelmetConstants.TAG_PROPERTIES.INNER_HTML || attributeKey === _HelmetConstants.TAG_PROPERTIES.CSS_TEXT || attributeKey === _HelmetConstants.TAG_PROPERTIES.ITEM_PROP)) {
                    primaryAttributeKey = attributeKey;
                }
            }

            if (!primaryAttributeKey || !tag[primaryAttributeKey]) {
                return false;
            }

            var value = tag[primaryAttributeKey].toLowerCase();

            if (!approvedSeenTags[primaryAttributeKey]) {
                approvedSeenTags[primaryAttributeKey] = {};
            }

            if (!instanceSeenTags[primaryAttributeKey]) {
                instanceSeenTags[primaryAttributeKey] = {};
            }

            if (!approvedSeenTags[primaryAttributeKey][value]) {
                instanceSeenTags[primaryAttributeKey][value] = true;
                return true;
            }

            return false;
        }).reverse().forEach(function (tag) {
            return approvedTags.push(tag);
        });

        // Update seen tags with tags from this instance
        var keys = Object.keys(instanceSeenTags);
        for (var i = 0; i < keys.length; i++) {
            var attributeKey = keys[i];
            var tagUnion = (0, _objectAssign2.default)({}, approvedSeenTags[attributeKey], instanceSeenTags[attributeKey]);

            approvedSeenTags[attributeKey] = tagUnion;
        }

        return approvedTags;
    }, []).reverse();
};

var updateTitle = function updateTitle(title, attributes) {
    document.title = title || document.title;
    updateAttributes(_HelmetConstants.TAG_NAMES.TITLE, attributes);
};

var updateAttributes = function updateAttributes(tagName, attributes) {
    var htmlTag = document.getElementsByTagName(tagName)[0];
    var helmetAttributeString = htmlTag.getAttribute(HELMET_ATTRIBUTE);
    var helmetAttributes = helmetAttributeString ? helmetAttributeString.split(",") : [];
    var attributesToRemove = [].concat(helmetAttributes);
    var attributeKeys = Object.keys(attributes);

    for (var i = 0; i < attributeKeys.length; i++) {
        var attribute = attributeKeys[i];
        var value = attributes[attribute] || "";
        htmlTag.setAttribute(attribute, value);

        if (helmetAttributes.indexOf(attribute) === -1) {
            helmetAttributes.push(attribute);
        }

        var indexToSave = attributesToRemove.indexOf(attribute);
        if (indexToSave !== -1) {
            attributesToRemove.splice(indexToSave, 1);
        }
    }

    for (var _i = attributesToRemove.length - 1; _i >= 0; _i--) {
        htmlTag.removeAttribute(attributesToRemove[_i]);
    }

    if (helmetAttributes.length === attributesToRemove.length) {
        htmlTag.removeAttribute(HELMET_ATTRIBUTE);
    } else {
        htmlTag.setAttribute(HELMET_ATTRIBUTE, helmetAttributes.join(","));
    }
};

var updateTags = function updateTags(type, tags) {
    var headElement = document.head || document.querySelector("head");
    var tagNodes = headElement.querySelectorAll(type + "[" + HELMET_ATTRIBUTE + "]");
    var oldTags = Array.prototype.slice.call(tagNodes);
    var newTags = [];
    var indexToDelete = void 0;

    if (tags && tags.length) {
        tags.forEach(function (tag) {
            var newElement = document.createElement(type);

            for (var attribute in tag) {
                if (tag.hasOwnProperty(attribute)) {
                    if (attribute === "innerHTML") {
                        newElement.innerHTML = tag.innerHTML;
                    } else if (attribute === "cssText") {
                        if (newElement.styleSheet) {
                            newElement.styleSheet.cssText = tag.cssText;
                        } else {
                            newElement.appendChild(document.createTextNode(tag.cssText));
                        }
                    } else {
                        var value = typeof tag[attribute] === "undefined" ? "" : tag[attribute];
                        newElement.setAttribute(attribute, value);
                    }
                }
            }

            newElement.setAttribute(HELMET_ATTRIBUTE, "true");

            // Remove a duplicate tag from domTagstoRemove, so it isn't cleared.
            if (oldTags.some(function (existingTag, index) {
                indexToDelete = index;
                return newElement.isEqualNode(existingTag);
            })) {
                oldTags.splice(indexToDelete, 1);
            } else {
                newTags.push(newElement);
            }
        });
    }

    oldTags.forEach(function (tag) {
        return tag.parentNode.removeChild(tag);
    });
    newTags.forEach(function (tag) {
        return headElement.appendChild(tag);
    });

    return {
        oldTags: oldTags,
        newTags: newTags
    };
};

var generateHtmlAttributesAsString = function generateHtmlAttributesAsString(attributes) {
    return Object.keys(attributes).reduce(function (str, key) {
        var attr = typeof attributes[key] !== "undefined" ? key + "=\"" + attributes[key] + "\"" : "" + key;
        return str ? str + " " + attr : attr;
    }, "");
};

var generateTitleAsString = function generateTitleAsString(type, title, attributes) {
    var attributeString = generateHtmlAttributesAsString(attributes);
    return attributeString ? "<" + type + " " + HELMET_ATTRIBUTE + " " + attributeString + ">" + encodeSpecialCharacters(title) + "</" + type + ">" : "<" + type + " " + HELMET_ATTRIBUTE + ">" + encodeSpecialCharacters(title) + "</" + type + ">";
};

var generateTagsAsString = function generateTagsAsString(type, tags) {
    return tags.reduce(function (str, tag) {
        var attributeHtml = Object.keys(tag).filter(function (attribute) {
            return !(attribute === "innerHTML" || attribute === "cssText");
        }).reduce(function (string, attribute) {
            var attr = typeof tag[attribute] === "undefined" ? attribute : attribute + "=\"" + encodeSpecialCharacters(tag[attribute]) + "\"";
            return string ? string + " " + attr : attr;
        }, "");

        var tagContent = tag.innerHTML || tag.cssText || "";

        var isSelfClosing = [_HelmetConstants.TAG_NAMES.NOSCRIPT, _HelmetConstants.TAG_NAMES.SCRIPT, _HelmetConstants.TAG_NAMES.STYLE].indexOf(type) === -1;

        return str + "<" + type + " " + HELMET_ATTRIBUTE + " " + attributeHtml + (isSelfClosing ? ">" : ">" + tagContent + "</" + type + ">");
    }, "");
};

var generateTitleAsPreactComponent = function generateTitleAsPreactComponent(type, title, attributes) {
    // assigning into an array to define toString function on it
    var initProps = _defineProperty({
        key: title
    }, HELMET_ATTRIBUTE, true);
    var props = Object.keys(attributes).reduce(function (obj, key) {
        obj[key] = attributes[key];
        return obj;
    }, initProps);

    return [(0, _preact.h)(_HelmetConstants.TAG_NAMES.TITLE, props, title)];
};

var generateTagsAsPreactComponent = function generateTagsAsPreactComponent(type, tags) {
    return tags.map(function (tag, i) {
        var mappedTag = _defineProperty({
            key: i
        }, HELMET_ATTRIBUTE, true);

        Object.keys(tag).forEach(function (attribute) {
            var mappedAttribute = attribute;

            if (mappedAttribute === "innerHTML" || mappedAttribute === "cssText") {
                var content = tag.innerHTML || tag.cssText;
                mappedTag.dangerouslySetInnerHTML = { __html: content };
            } else {
                mappedTag[mappedAttribute] = tag[attribute];
            }
        });

        return (0, _preact.h)(type, mappedTag);
    });
};

var getMethodsForTag = function getMethodsForTag(type, tags) {
    switch (type) {
        case _HelmetConstants.TAG_NAMES.TITLE:
            return {
                toComponent: function toComponent() {
                    return generateTitleAsPreactComponent(type, tags.title, tags.titleAttributes);
                },
                toString: function toString() {
                    return generateTitleAsString(type, tags.title, tags.titleAttributes);
                }
            };
        case _HelmetConstants.TAG_NAMES.HTML:
            return {
                toComponent: function toComponent() {
                    return tags;
                },
                toString: function toString() {
                    return generateHtmlAttributesAsString(tags);
                }
            };
        default:
            return {
                toComponent: function toComponent() {
                    return generateTagsAsPreactComponent(type, tags);
                },
                toString: function toString() {
                    return generateTagsAsString(type, tags);
                }
            };
    }
};

var mapStateOnServer = function mapStateOnServer(_ref) {
    var htmlAttributes = _ref.htmlAttributes,
        title = _ref.title,
        titleAttributes = _ref.titleAttributes,
        baseTag = _ref.baseTag,
        metaTags = _ref.metaTags,
        linkTags = _ref.linkTags,
        scriptTags = _ref.scriptTags,
        noscriptTags = _ref.noscriptTags,
        styleTags = _ref.styleTags;
    return {
        htmlAttributes: getMethodsForTag(_HelmetConstants.TAG_NAMES.HTML, htmlAttributes),
        title: getMethodsForTag(_HelmetConstants.TAG_NAMES.TITLE, { title: title, titleAttributes: titleAttributes }),
        base: getMethodsForTag(_HelmetConstants.TAG_NAMES.BASE, baseTag),
        meta: getMethodsForTag(_HelmetConstants.TAG_NAMES.META, metaTags),
        link: getMethodsForTag(_HelmetConstants.TAG_NAMES.LINK, linkTags),
        script: getMethodsForTag(_HelmetConstants.TAG_NAMES.SCRIPT, scriptTags),
        noscript: getMethodsForTag(_HelmetConstants.TAG_NAMES.NOSCRIPT, noscriptTags),
        style: getMethodsForTag(_HelmetConstants.TAG_NAMES.STYLE, styleTags)
    };
};

/**
 * @param {Object} htmlAttributes: {"lang": "en", "amp": undefined}
 * @param {String} title: "Title"
 * @param {String} defaultTitle: "Default Title"
 * @param {String} titleTemplate: "MySite.com - %s"
 * @param {Object} titleAttributes: {"itemprop": "name"}
 * @param {Object} base: {"target": "_blank", "href": "http://mysite.com/"}
 * @param {Array} meta: [{"name": "description", "content": "Test description"}]
 * @param {Array} link: [{"rel": "canonical", "href": "http://mysite.com/example"}]
 * @param {Array} script: [{"type": "text/javascript", "src": "http://mysite.com/js/test.js"}]
 * @param {Array} noscript: [{"innerHTML": "<img src='http://mysite.com/js/test.js'"}]
 * @param {Array} style: [{"type": "text/css", "cssText": "div{ display: block; color: blue; }"}]
 * @param {Function} onChangeClientState: "(newState) => console.log(newState)"
 */
var Helmet = function Helmet(WrappedComponent) {
    var _class, _temp;

    return _temp = _class = function (_Component) {
        _inherits(HelmetWrapper, _Component);

        function HelmetWrapper() {
            _classCallCheck(this, HelmetWrapper);

            return _possibleConstructorReturn(this, (HelmetWrapper.__proto__ || Object.getPrototypeOf(HelmetWrapper)).apply(this, arguments));
        }

        _createClass(HelmetWrapper, [{
            key: "shouldComponentUpdate",
            value: function shouldComponentUpdate(nextProps) {
                var props = _extends({}, nextProps);
                if (!props.children || !props.children.length) {
                    delete props.children;
                }
                return !(0, _deepEqual2.default)(this.props, props);
            }
        }, {
            key: "render",
            value: function render() {
                return (0, _preact.h)(WrappedComponent, this.props);
            }
        }], [{
            key: "canUseDOM",

            // WrappedComponent.peek comes from react-side-effect:
            // For testing, you may use a static peek() method available on the returned component.
            // It lets you get the current state without resetting the mounted instance stack.
            // Don’t use it for anything other than testing.
            set: function set(canUseDOM) {
                WrappedComponent.canUseDOM = canUseDOM;
            }
        }]);

        return HelmetWrapper;
    }(_preact.Component), _class.peek = WrappedComponent.peek, _class.rewind = function () {
        var mappedState = WrappedComponent.rewind();
        if (!mappedState) {
            // provide fallback if mappedState is undefined
            mappedState = mapStateOnServer({
                htmlAttributes: {},
                title: "",
                titleAttributes: {},
                baseTag: [],
                metaTags: [],
                linkTags: [],
                scriptTags: [],
                noscriptTags: [],
                styleTags: []
            });
        }

        return mappedState;
    }, _temp;
};

var reducePropsToState = function reducePropsToState(propsList) {
    return {
        htmlAttributes: getAttributesFromPropsList(_HelmetConstants.TAG_NAMES.HTML, propsList),
        title: getTitleFromPropsList(propsList),
        titleAttributes: getAttributesFromPropsList("titleAttributes", propsList),
        baseTag: getBaseTagFromPropsList([_HelmetConstants.TAG_PROPERTIES.HREF], propsList),
        metaTags: getTagsFromPropsList(_HelmetConstants.TAG_NAMES.META, [_HelmetConstants.TAG_PROPERTIES.NAME, _HelmetConstants.TAG_PROPERTIES.CHARSET, _HelmetConstants.TAG_PROPERTIES.HTTPEQUIV, _HelmetConstants.TAG_PROPERTIES.PROPERTY, _HelmetConstants.TAG_PROPERTIES.ITEM_PROP], propsList),
        linkTags: getTagsFromPropsList(_HelmetConstants.TAG_NAMES.LINK, [_HelmetConstants.TAG_PROPERTIES.REL, _HelmetConstants.TAG_PROPERTIES.HREF], propsList),
        scriptTags: getTagsFromPropsList(_HelmetConstants.TAG_NAMES.SCRIPT, [_HelmetConstants.TAG_PROPERTIES.SRC, _HelmetConstants.TAG_PROPERTIES.INNER_HTML], propsList),
        noscriptTags: getTagsFromPropsList(_HelmetConstants.TAG_NAMES.NOSCRIPT, [_HelmetConstants.TAG_PROPERTIES.INNER_HTML], propsList),
        styleTags: getTagsFromPropsList(_HelmetConstants.TAG_NAMES.STYLE, [_HelmetConstants.TAG_PROPERTIES.CSS_TEXT], propsList),
        onChangeClientState: getOnChangeClientState(propsList)
    };
};

var handleClientStateChange = function handleClientStateChange(newState) {
    var htmlAttributes = newState.htmlAttributes,
        title = newState.title,
        titleAttributes = newState.titleAttributes,
        baseTag = newState.baseTag,
        metaTags = newState.metaTags,
        linkTags = newState.linkTags,
        scriptTags = newState.scriptTags,
        noscriptTags = newState.noscriptTags,
        styleTags = newState.styleTags,
        onChangeClientState = newState.onChangeClientState;


    updateAttributes("html", htmlAttributes);

    updateTitle(title, titleAttributes);

    var tagUpdates = {
        baseTag: updateTags(_HelmetConstants.TAG_NAMES.BASE, baseTag),
        metaTags: updateTags(_HelmetConstants.TAG_NAMES.META, metaTags),
        linkTags: updateTags(_HelmetConstants.TAG_NAMES.LINK, linkTags),
        scriptTags: updateTags(_HelmetConstants.TAG_NAMES.SCRIPT, scriptTags),
        noscriptTags: updateTags(_HelmetConstants.TAG_NAMES.NOSCRIPT, noscriptTags),
        styleTags: updateTags(_HelmetConstants.TAG_NAMES.STYLE, styleTags)
    };

    var addedTags = {};
    var removedTags = {};

    Object.keys(tagUpdates).forEach(function (tagType) {
        var _tagUpdates$tagType = tagUpdates[tagType],
            newTags = _tagUpdates$tagType.newTags,
            oldTags = _tagUpdates$tagType.oldTags;


        if (newTags.length) {
            addedTags[tagType] = newTags;
        }
        if (oldTags.length) {
            removedTags[tagType] = tagUpdates[tagType].oldTags;
        }
    });

    onChangeClientState(newState, addedTags, removedTags);
};

var NullComponent = function NullComponent() {
    return null;
};

var HelmetSideEffects = (0, _preactSideEffect2.default)(reducePropsToState, handleClientStateChange, mapStateOnServer)(NullComponent);

exports.default = Helmet(HelmetSideEffects);
module.exports = exports["default"];