From 833fe49e6ff934eed3f8f8c149e81718b1333850 Mon Sep 17 00:00:00 2001
From: Hannah Wolfe <erisds@gmail.com>
Date: Thu, 18 Jul 2019 15:25:19 +0100
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8Added=20{{link}}=20helper?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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- {{#link}}{{/link}} working with all attributes supported and dynamic active class
---
 core/frontend/helpers/index.js       |   2 +
 core/frontend/helpers/link.js        | 101 ++++++++
 core/test/unit/helpers/index_spec.js |   2 +-
 core/test/unit/helpers/link_spec.js  | 356 +++++++++++++++++++++++++++
 4 files changed, 460 insertions(+), 1 deletion(-)
 create mode 100644 core/frontend/helpers/link.js
 create mode 100644 core/test/unit/helpers/link_spec.js

diff --git a/core/frontend/helpers/index.js b/core/frontend/helpers/index.js
index 6aa749296c..a11c9a49c2 100644
--- a/core/frontend/helpers/index.js
+++ b/core/frontend/helpers/index.js
@@ -22,6 +22,7 @@ coreHelpers.img_url = require('./img_url');
 coreHelpers.is = require('./is');
 coreHelpers.has = require('./has');
 coreHelpers.lang = require('./lang');
+coreHelpers.link = require('./link');
 coreHelpers.meta_description = require('./meta_description');
 coreHelpers.meta_title = require('./meta_title');
 coreHelpers.navigation = require('./navigation');
@@ -55,6 +56,7 @@ registerAllCoreHelpers = function registerAllCoreHelpers() {
     registerThemeHelper('is', coreHelpers.is);
     registerThemeHelper('img_url', coreHelpers.img_url);
     registerThemeHelper('lang', coreHelpers.lang);
+    registerThemeHelper('link', coreHelpers.link);
     registerThemeHelper('meta_description', coreHelpers.meta_description);
     registerThemeHelper('meta_title', coreHelpers.meta_title);
     registerThemeHelper('navigation', coreHelpers.navigation);
diff --git a/core/frontend/helpers/link.js b/core/frontend/helpers/link.js
new file mode 100644
index 0000000000..af1c171d4a
--- /dev/null
+++ b/core/frontend/helpers/link.js
@@ -0,0 +1,101 @@
+// # link helper
+const _ = require('lodash');
+const {config, SafeString} = require('./proxy');
+
+const managedAttributes = ['href', 'class', 'activeClass', 'parentActiveClass', 'tagName', 'nohref'];
+
+function _getHref(hash) {
+    let href = hash.href || '/';
+    return href.string ? href.string : href;
+}
+
+function _clean(url) {
+    // Strips anchors and leading and trailing slashes
+    return url.replace(/#.*?$/, '').replace(/^\/|\/$/g, '');
+}
+
+// strips trailing slashes and compares urls
+function _urlMatch(href, location) {
+    if (!location) {
+        return false;
+    }
+
+    const strippedHref = _clean(href);
+    const strippedLocation = _clean(location);
+
+    return strippedHref === strippedLocation;
+}
+
+// We want to check if the first part of the current url is a match for href
+function _parentMatch(href, location) {
+    if (!location) {
+        return false;
+    }
+
+    let parent = false;
+    let locParts = _clean(location).split('/');
+    let hrefParts = _clean(href).split('/');
+
+    if (locParts.length <= hrefParts.length) {
+        return false;
+    }
+
+    for (let i = 0; i < hrefParts.length; i += 1) {
+        parent = hrefParts[i] === locParts[i];
+    }
+
+    return parent;
+}
+
+function _formatAttrs(attributes) {
+    let attributeString = '';
+    Object.keys(attributes).forEach((key) => {
+        let value = attributes[key];
+
+        // @TODO handle non-string attributes?
+        attributeString += `${key}="${value}"`;
+    });
+
+    return attributeString;
+}
+
+module.exports = function link(options) {
+    options = options || {};
+    options.hash = options.hash || {};
+    options.data = options.data || {};
+
+    let href = _getHref(options.hash);
+    let location = options.data.root.relativeUrl;
+    let tagName = options.hash.tagName || 'a';
+    let activeClass = _.has(options.hash, 'activeClass') ? options.hash.activeClass : 'nav-current';
+    let parentActiveClass = _.has(options.hash, 'parentActiveClass') ? options.hash.parentActiveClass : `${activeClass || 'nav-current'}-parent`;
+    let classes = options.hash.class ? options.hash.class.toString().split(' ') : [];
+    let noHref = _.has(options.hash, 'nohref') ? options.hash.nohref : false;
+
+    // Remove all the attributes we don't want to do a one-to-one mapping of
+    managedAttributes.forEach((attr) => {
+        delete options.hash[attr];
+    });
+
+    // Setup our one-to-one mapping of attributes;
+    let attributes = options.hash;
+
+    // Calculate dynamic properties
+    let relativeHref = href.replace(config.get('url'), '');
+    if (_urlMatch(relativeHref, location) && activeClass) {
+        classes.push(activeClass);
+    } else if (_parentMatch(relativeHref, location) && parentActiveClass) {
+        classes.push(parentActiveClass);
+    }
+
+    // Prepare output
+    let classString = classes.length > 0 ? `class="${classes.join(' ')}"` : '';
+    let hrefString = !noHref ? `href="${href}"` : '';
+    let attributeString = _.size(attributes) > 0 ? _formatAttrs(attributes) : '';
+    let openingTag = `<${tagName} ${classString} ${hrefString} ${attributeString}>`;
+    let closingTag = `</${tagName}>`;
+    // Clean up any extra spaces
+    openingTag = openingTag.replace(/\s{2,}/g, ' ').replace(/\s>/, '>');
+
+    return new SafeString(`${openingTag}${options.fn(this)}${closingTag}`);
+};
diff --git a/core/test/unit/helpers/index_spec.js b/core/test/unit/helpers/index_spec.js
index 17de88a4c8..37a5e867f9 100644
--- a/core/test/unit/helpers/index_spec.js
+++ b/core/test/unit/helpers/index_spec.js
@@ -9,7 +9,7 @@ describe('Helpers', function () {
     var hbsHelpers = ['each', 'if', 'unless', 'with', 'helperMissing', 'blockHelperMissing', 'log', 'lookup', 'block', 'contentFor'],
         ghostHelpers = [
             'asset', 'author', 'authors', 'body_class', 'concat', 'content', 'date', 'encode', 'excerpt', 'facebook_url', 'foreach', 'get',
-            'ghost_foot', 'ghost_head', 'has', 'img_url', 'is', 'lang', 'meta_description', 'meta_title', 'navigation',
+            'ghost_foot', 'ghost_head', 'has', 'img_url', 'is', 'lang', 'link', 'meta_description', 'meta_title', 'navigation',
             'next_post', 'page_url', 'pagination', 'plural', 'post_class', 'prev_post', 'reading_time', 't', 'tags', 'title', 'twitter_url',
             'url'
         ],
diff --git a/core/test/unit/helpers/link_spec.js b/core/test/unit/helpers/link_spec.js
new file mode 100644
index 0000000000..757652e80c
--- /dev/null
+++ b/core/test/unit/helpers/link_spec.js
@@ -0,0 +1,356 @@
+const should = require('should');
+const helpers = require.main.require('core/frontend/helpers');
+const handlebars = require.main.require('core/frontend/services/themes/engine').handlebars;
+
+const configUtils = require('../../utils/configUtils');
+
+let defaultGlobals;
+
+function compile(templateString) {
+    const template = handlebars.compile(templateString);
+    template.with = (locals = {}, globals) => {
+        globals = globals || defaultGlobals;
+
+        return template(locals, globals);
+    };
+
+    return template;
+}
+
+describe('{{link}} helper', function () {
+    before(function () {
+        handlebars.registerHelper('link', helpers.link);
+        handlebars.registerHelper('url', helpers.url);
+        handlebars.registerHelper('concat', helpers.concat);
+        configUtils.config.set('url', 'https://siteurl.com');
+        defaultGlobals = {
+            data: {
+                site: {
+                    url: configUtils.config.get('url')
+                }
+            }
+        };
+    });
+
+    after(function () {
+        configUtils.restore();
+    });
+
+    describe('basic behaviour: simple links without context', function () {
+        it('basic <a> tag with default url', function () {
+            compile('{{#link}}text{{/link}}')
+                .with({})
+                .should.eql('<a href="/">text</a>');
+        });
+
+        it('<a> tag with a specific URL', function () {
+            compile('{{#link href="/about/"}}text{{/link}}')
+                .with({})
+                .should.eql('<a href="/about/">text</a>');
+        });
+
+        it('<a> tag with an anchor', function () {
+            compile('{{#link href="#myheading"}}text{{/link}}')
+                .with({})
+                .should.eql('<a href="#myheading">text</a>');
+        });
+
+        it('<a> tag with global variable', function () {
+            compile('{{#link href=@site.url}}text{{/link}}')
+                .with({})
+                .should.eql('<a href="https://siteurl.com">text</a>');
+        });
+
+        it('<a> tag with local variable', function () {
+            compile('{{#link href=tag.slug}}text{{/link}}')
+                .with({tag: {slug: 'my-tag'}})
+                .should.eql('<a href="my-tag">text</a>');
+        });
+
+        it('<a> tag with nested helpers', function () {
+            compile('{{#link href=(url)}}{{title}}{{/link}}')
+            // Simulate a post - using a draft to prove url helper gets called
+            // because published posts get their urls from a cache that we don't have access to, so we just get 404
+                .with({title: 'My Draft Post', slug: 'my-post', html: '<p>My Post</p>', uuid: '1234'})
+                .should.eql('<a href="/p/1234/">My Draft Post</a>');
+        });
+
+        it('can wrap html content', function () {
+            compile('{{#link href="/"}}<img src="myfile.jpg" />{{/link}}')
+                .with({})
+                .should.eql('<a href="/"><img src="myfile.jpg" /></a>');
+        });
+
+        it('honours class attribute', function () {
+            compile('{{#link href="#myheading" class="my-class"}}text{{/link}}')
+                .with({})
+                .should.eql('<a class="my-class" href="#myheading">text</a>');
+        });
+
+        it('supports multiple classes', function () {
+            compile('{{#link href="#myheading" class="my-class and-stuff"}}text{{/link}}')
+                .with({})
+                .should.eql('<a class="my-class and-stuff" href="#myheading">text</a>');
+        });
+
+        it('can handle classes that come from variables', function () {
+            compile('{{#link href="#myheading" class=slug}}text{{/link}}')
+            .with({slug: 'fred'})
+            .should.eql('<a class="fred" href="#myheading">text</a>');
+        });
+
+        it('can handle classes that come from helpers', function () {
+            compile('{{#link href="#myheading" class=(concat "my-" slug)}}text{{/link}}')
+            .with({slug: 'fred'})
+            .should.eql('<a class="my-fred" href="#myheading">text</a>');
+        });
+
+        it('supports multiple attributes', function () {
+            compile('{{#link href="#myheading" class="my-class" target="_blank"}}text{{/link}}')
+                .with({})
+                .should.eql('<a class="my-class" href="#myheading" target="_blank">text</a>');
+        });
+    });
+
+    describe('dynamic behaviour: advanced links using context', function () {
+        describe('activeClass', function () {
+            it('gets applied correctly', function () {
+                // Test matching relative URL
+                compile('{{#link href="/about/"}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="nav-current" href="/about/">text</a>');
+
+                // Test non-matching relative URL
+                compile('{{#link href="/about/"}}text{{/link}}')
+                    .with({relativeUrl: '/'})
+                    .should.eql('<a href="/about/">text</a>');
+            });
+
+            it('ignores anchors', function () {
+                // Anchor in href
+                compile('{{#link href="/about/#me"}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="nav-current" href="/about/#me">text</a>');
+
+                // Anchor in relative URL
+                compile('{{#link href="/about/"}}text{{/link}}')
+                    .with({relativeUrl: '/about/#me'})
+                    .should.eql('<a class="nav-current" href="/about/">text</a>');
+            });
+
+            it('handles missing trailing slashes', function () {
+                compile('{{#link href="/about"}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="nav-current" href="/about">text</a>');
+            });
+
+            it('handles absolute URLs', function () {
+                // Correct URL gets class
+                compile('{{#link href="https://siteurl.com/about/"}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="nav-current" href="https://siteurl.com/about/">text</a>');
+
+                // Incorrect URL doesn't get class
+                compile('{{#link href="https://othersite.com/about/"}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a href="https://othersite.com/about/">text</a>');
+            });
+
+            it('handles absolute URL with missing trailing slash', function () {
+                compile('{{#link href="https://siteurl.com/about"}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="nav-current" href="https://siteurl.com/about">text</a>');
+            });
+
+            it('activeClass can be customised', function () {
+                compile('{{#link href="/about/" activeClass="nav-active"}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="nav-active" href="/about/">text</a>');
+
+                compile('{{#link href="/about/" activeClass=slug}}text{{/link}}')
+                    .with({relativeUrl: '/about/', slug: 'fred'})
+                    .should.eql('<a class="fred" href="/about/">text</a>');
+
+                compile('{{#link href="/about/" activeClass=(concat slug "active" separator="-")}}text{{/link}}')
+                    .with({relativeUrl: '/about/', slug: 'fred'})
+                    .should.eql('<a class="fred-active" href="/about/">text</a>');
+            });
+
+            it('activeClass and other classes work together', function () {
+                // Single extra class
+                compile('{{#link href="/about/" class="about"}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="about nav-current" href="/about/">text</a>');
+
+                // Multiple extra classes
+                compile('{{#link href="/about/" class="about my-link"}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="about my-link nav-current" href="/about/">text</a>');
+            });
+
+            it('can disable activeClass with falsey values', function () {
+                // Empty string
+                compile('{{#link href="/about/" activeClass=""}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a href="/about/">text</a>');
+
+                // false
+                compile('{{#link href="/about/" activeClass=false}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a href="/about/">text</a>');
+            });
+        });
+
+        describe('parentActiveClass', function () {
+            it('gets applied correctly', function () {
+                // Parent and child links with PARENT as relative URL
+                compile('{{#link href="/about/"}}parent{{/link}}{{#link href="/about/team/"}}child{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="nav-current" href="/about/">parent</a><a href="/about/team/">child</a>');
+
+                // Parent and child links with CHILD as relative URL
+                compile('{{#link href="/about/"}}parent{{/link}}{{#link href="/about/team/"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a class="nav-current-parent" href="/about/">parent</a><a class="nav-current" href="/about/team/">child</a>');
+            });
+
+            it('ignores anchors', function () {
+                // Anchor in href
+
+                // Parent and child links with PARENT as relative URL
+                compile('{{#link href="/about/#me"}}parent{{/link}}{{#link href="/about/team/"}}child{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="nav-current" href="/about/#me">parent</a><a href="/about/team/">child</a>');
+
+                // Parent and child links with CHILD as relative URL
+                compile('{{#link href="/about/#me"}}parent{{/link}}{{#link href="/about/team/"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a class="nav-current-parent" href="/about/#me">parent</a><a class="nav-current" href="/about/team/">child</a>');
+
+                // Anchor in relative URL
+
+                // Parent and child links with PARENT as relative URL
+                compile('{{#link href="/about/"}}parent{{/link}}{{#link href="/about/team/"}}child{{/link}}')
+                    .with({relativeUrl: '/about/#me'})
+                    .should.eql('<a class="nav-current" href="/about/">parent</a><a href="/about/team/">child</a>');
+
+                // Parent and child links with CHILD as relative URL
+                compile('{{#link href="/about/"}}parent{{/link}}{{#link href="/about/team/"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/#me'})
+                    .should.eql('<a class="nav-current-parent" href="/about/">parent</a><a class="nav-current" href="/about/team/">child</a>');
+            });
+
+            it('handles missing trailing slashes', function () {
+                // Parent and child links with PARENT as relative URL
+                compile('{{#link href="/about"}}parent{{/link}}{{#link href="/about/team"}}child{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="nav-current" href="/about">parent</a><a href="/about/team">child</a>');
+
+                // Parent and child links with CHILD as relative URL
+                compile('{{#link href="/about"}}parent{{/link}}{{#link href="/about/team"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a class="nav-current-parent" href="/about">parent</a><a class="nav-current" href="/about/team">child</a>');
+            });
+
+            it('handles absolute URLs', function () {
+                // Correct URL gets class
+
+                // Parent and child links with PARENT as relative URL
+                compile('{{#link href="https://siteurl.com/about/"}}parent{{/link}}{{#link href="https://siteurl.com/about/team/"}}child{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="nav-current" href="https://siteurl.com/about/">parent</a><a href="https://siteurl.com/about/team/">child</a>');
+
+                // Parent and child links with CHILD as relative URL
+                compile('{{#link href="https://siteurl.com/about/"}}parent{{/link}}{{#link href="https://siteurl.com/about/team/"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a class="nav-current-parent" href="https://siteurl.com/about/">parent</a><a class="nav-current" href="https://siteurl.com/about/team/">child</a>');
+
+                // Incorrect URL doesn't get class
+
+                // Parent and child links with PARENT as relative URL
+                compile('{{#link href="https://othersite.com/about/"}}parent{{/link}}{{#link href="https://othersite.com/about/team/"}}child{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a href="https://othersite.com/about/">parent</a><a href="https://othersite.com/about/team/">child</a>');
+
+                // Parent and child links with CHILD as relative URL
+                compile('{{#link href="https://othersite.com/about/"}}parent{{/link}}{{#link href="https://othersite.com/about/team/"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a href="https://othersite.com/about/">parent</a><a href="https://othersite.com/about/team/">child</a>');
+            });
+
+            it('handles absolute URLs with missing trailing slashes', function () {
+                // Parent and child links with PARENT as relative URL
+                compile('{{#link href="https://siteurl.com/about"}}parent{{/link}}{{#link href="https://siteurl.com/about/team"}}child{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<a class="nav-current" href="https://siteurl.com/about">parent</a><a href="https://siteurl.com/about/team">child</a>');
+
+                // Parent and child links with CHILD as relative URL
+                compile('{{#link href="https://siteurl.com/about"}}parent{{/link}}{{#link href="https://siteurl.com/about/team"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a class="nav-current-parent" href="https://siteurl.com/about">parent</a><a class="nav-current" href="https://siteurl.com/about/team">child</a>');
+            });
+
+            it('parentActiveClass can be customised', function () {
+                compile('{{#link href="/about/" parentActiveClass="parent"}}parent{{/link}}{{#link href="/about/team/"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a class="parent" href="/about/">parent</a><a class="nav-current" href="/about/team/">child</a>');
+
+                compile('{{#link href="/about/" parentActiveClass="parent"}}parent{{/link}}{{#link href="/about/team/" parentActiveClass="parent"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a class="parent" href="/about/">parent</a><a class="nav-current" href="/about/team/">child</a>');
+
+                compile('{{#link href="/about/" parentActiveClass=slug}}parent{{/link}}{{#link href="/about/team/" parentActiveClass="parent"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/', slug: 'fred'})
+                    .should.eql('<a class="fred" href="/about/">parent</a><a class="nav-current" href="/about/team/">child</a>');
+
+                compile('{{#link href="/about/" parentActiveClass=(concat slug "-parent")}}parent{{/link}}{{#link href="/about/team/" parentActiveClass="parent"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/', slug: 'fred'})
+                    .should.eql('<a class="fred-parent" href="/about/">parent</a><a class="nav-current" href="/about/team/">child</a>');
+            });
+
+            it('customising activeClass also customises parentActiveClass', function () {
+                compile('{{#link href="/about/" activeClass="active"}}parent{{/link}}{{#link href="/about/team/" activeClass="active"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a class="active-parent" href="/about/">parent</a><a class="active" href="/about/team/">child</a>');
+
+                compile('{{#link href="/about/" activeClass="active" parentActiveClass="parent"}}parent{{/link}}{{#link href="/about/team/" activeClass="active"}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a class="parent" href="/about/">parent</a><a class="active" href="/about/team/">child</a>');
+            });
+
+            it('can disable parentActiveClass with falsey values', function () {
+                compile('{{#link href="/about/" parentActiveClass=""}}text{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a href="/about/">text</a>');
+
+                compile('{{#link href="/about/" parentActiveClass=false}}text{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a href="/about/">text</a>');
+            });
+
+            it('disabling activeClass does not affect parentActiveClass', function () {
+                compile('{{#link href="/about/" activeClass=""}}parent{{/link}}{{#link href="/about/team/" activeClass=""}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a class="nav-current-parent" href="/about/">parent</a><a href="/about/team/">child</a>');
+
+                compile('{{#link href="/about/" activeClass=false parentActiveClass="parent"}}parent{{/link}}{{#link href="/about/team/" activeClass=false}}child{{/link}}')
+                    .with({relativeUrl: '/about/team/'})
+                    .should.eql('<a class="parent" href="/about/">parent</a><a href="/about/team/">child</a>');
+            });
+        });
+
+        describe('custom tag', function () {
+            it('can change tag', function () {
+                compile('{{#link href="/about/" class="my-class" tagName="li"}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<li class="my-class nav-current" href="/about/">text</li>');
+            });
+
+            it('can change tag and disable href', function () {
+                compile('{{#link href="/about/" class="my-class" tagName="li" nohref=true}}text{{/link}}')
+                    .with({relativeUrl: '/about/'})
+                    .should.eql('<li class="my-class nav-current">text</li>');
+            });
+        });
+    });
+});