Divided f/e proxy into true proxy + rendering service

- The original intention of the proxy was to collect up all the requires in our helpers into one place
- This has since been expanded and used in more places, in more ways
- In hindsight there are now multiple different types of requires in the proxy:
   - One: true frontend rendering framework requires (stuff from deep inside theme-engine)
   - Two: data manipulation/sdk stuff, belongs to the frontend, ways to process API data
   - Three: actual core stuff from Ghost, that we wish wasn't here / needs to be passed in a controlled way
- This commit pulls out One into a new rendering service, so at least that stuff is managed independently
- This draws the lines clearly between what's internal to the frontend and what isn't
- It also highlights that the theme-engine needs to be divided up / refactored so that we don't have these deep requires

core/frontend/apps/amp/lib/helpers/amp_analytics.js

@@ -2,8 +2,8 @@
 // Usage: `{{amp_analytics}}`
 //
 // Outputs inline scripts used for analytics
-
-const {SafeString, settingsCache} = require('../../../../services/proxy');
+const {settingsCache} = require('../../../../services/proxy');
+const {SafeString} = require('../../../../services/rendering');
 
 function ampComponents() {
     let components = [];

core/frontend/apps/amp/lib/helpers/amp_components.js

@@ -8,7 +8,8 @@
 // By default supported AMP HTML tags (no additional script tag necessary):
 // amp-img, amp-ad, amp-embed, amp-video and amp-pixel.
 // (less) dirty requires
-const {SafeString, settingsCache} = require('../../../../services/proxy');
+const {settingsCache} = require('../../../../services/proxy');
+const {SafeString} = require('../../../../services/rendering');
 
 function ampComponents() {
     let components = [];

core/frontend/apps/amp/lib/helpers/amp_content.js

@@ -12,7 +12,7 @@ const moment = require('moment');
 const errors = require('@tryghost/errors');
 const logging = require('@tryghost/logging');
 
-const {SafeString} = require('../../../../services/proxy');
+const {SafeString} = require('../../../../services/rendering');
 
 const amperizeCache = {};
 let allowedAMPTags = [];

core/frontend/apps/amp/lib/helpers/amp_style.js

@@ -1,4 +1,4 @@
-const {SafeString, escapeExpression} = require('../../../../services/proxy');
+const {SafeString, escapeExpression} = require('../../../../services/rendering');
 
 module.exports = function amp_style(options) { // eslint-disable-line camelcase
     if (options.data.site.accent_color) {

core/frontend/apps/private-blogging/lib/helpers/input_password.js

@@ -4,7 +4,7 @@
 // Password input used on private.hbs for password-protected blogs
 
 // (less) dirty requires
-const {SafeString, templates} = require('../../../../services/proxy');
+const {SafeString, templates} = require('../../../../services/rendering');
 
 // We use the name input_password to match the helper for consistency:
 module.exports = function input_password(options) { // eslint-disable-line camelcase

core/frontend/helpers/asset.js

@@ -2,7 +2,8 @@
 // Usage: `{{asset "css/screen.css"}}`
 //
 // Returns the path to the specified asset.
-const {SafeString, metaData} = require('../services/proxy');
+const {metaData} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 
 const errors = require('@tryghost/errors');
 const tpl = require('@tryghost/tpl');

core/frontend/helpers/author.js

@@ -9,16 +9,18 @@
 //
 // Block helper: `{{#author}}{{/author}}`
 // This is the default handlebars behaviour of dropping into the author object scope
-const {urlService, SafeString, escapeExpression, hbs, templates} = require('../services/proxy');
-const buildInHelpers = hbs.handlebars.helpers;
+const {urlService} = require('../services/proxy');
+const {SafeString, escapeExpression, hbs, templates} = require('../services/rendering');
 const isString = require('lodash/isString');
 
+const builtInHelpers = hbs.handlebars.helpers;
+
 /**
  * @deprecated: single authors was superceded by multiple authors in Ghost 1.22.0
  */
 module.exports = function author(options) {
     if (options.fn) {
-        return buildInHelpers.with.call(this, this.author, options);
+        return builtInHelpers.with.call(this, this.author, options);
     }
 
     const autolink = isString(options.hash.autolink) && options.hash.autolink === 'false' ? false : true;

core/frontend/helpers/authors.js

@@ -6,9 +6,10 @@
 // By default, authors are separated by commas.
 //
 // Note that the standard {{#each authors}} implementation is unaffected by this helper.
+const {urlService} = require('../services/proxy');
+const {SafeString, escapeExpression, templates} = require('../services/rendering');
 const isString = require('lodash/isString');
-const {SafeString, escapeExpression, templates, urlService} = require('../services/proxy');
-const ghostHelperUtils = require('@tryghost/helpers').utils;
+const {utils} = require('@tryghost/helpers');
 
 module.exports = function authors(options = {}) {
     options.hash = options.hash || {};
@@ -38,7 +39,7 @@ module.exports = function authors(options = {}) {
             }) : escapeExpression(author.name);
         }
 
-        return ghostHelperUtils.visibility.filter(authorsList, visibility, processAuthor);
+        return utils.visibility.filter(authorsList, visibility, processAuthor);
     }
 
     if (this.authors && this.authors.length) {

core/frontend/helpers/body_class.js

@@ -2,7 +2,7 @@
 // Usage: `{{body_class}}`
 //
 // Output classes for the body element
-const {SafeString} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 
 // We use the name body_class to match the helper for consistency
 module.exports = function body_class(options) { // eslint-disable-line camelcase

core/frontend/helpers/cancel_link.js

@@ -5,7 +5,8 @@
 // Outputs cancel/renew links to manage subscription renewal after the subscription period ends.
 //
 // Defaults to class="cancel-subscription-link" errorClass="cancel-subscription-error" cancelLabel="Cancel subscription" continueLabel="Continue subscription"
-const {templates, labs} = require('../services/proxy');
+const {labs} = require('../services/proxy');
+const {templates} = require('../services/rendering');
 
 const errors = require('@tryghost/errors');
 const tpl = require('@tryghost/tpl');

core/frontend/helpers/concat.js

@@ -1,4 +1,4 @@
-const {SafeString} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 
 module.exports = function concat(...args) {
     const options = args.pop();

core/frontend/helpers/content.js

@@ -10,7 +10,7 @@
 //
 // Dev flag feature: In case of restricted content access for member-only posts, shows CTA box
 
-const {templates, hbs, SafeString} = require('../services/proxy');
+const {templates, hbs, SafeString} = require('../services/rendering');
 const downsize = require('downsize');
 const _ = require('lodash');
 const createFrame = hbs.handlebars.createFrame;

core/frontend/helpers/date.js

@@ -3,7 +3,7 @@
 //
 // Formats a date using moment-timezone.js. Formats published_at by default but will also take a date as a parameter
 
-const {SafeString} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 const moment = require('moment-timezone');
 const _ = require('lodash');
 

core/frontend/helpers/encode.js

@@ -4,7 +4,7 @@
 //
 // Returns URI encoded string
 
-const {SafeString} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 
 module.exports = function encode(string, options) {
     const uri = string || options;

core/frontend/helpers/excerpt.js

@@ -5,7 +5,8 @@
 //
 // Defaults to words="50"
 
-const {SafeString, metaData} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
+const {metaData} = require('../services/proxy');
 const _ = require('lodash');
 const getMetaDataExcerpt = metaData.getMetaDataExcerpt;
 

core/frontend/helpers/facebook_url.js

@@ -2,7 +2,8 @@
 // Usage: `{{facebook_url}}` or `{{facebook_url author.facebook}}`
 //
 // Output a url for a facebook username
-const {socialUrls, localUtils} = require('../services/proxy');
+const {socialUrls} = require('../services/proxy');
+const {localUtils} = require('../services/rendering');
 
 // We use the name facebook_url to match the helper for consistency:
 module.exports = function facebook_url(username, options) { // eslint-disable-line camelcase

core/frontend/helpers/foreach.js

@@ -2,7 +2,8 @@
 // Usage: `{{#foreach data}}{{/foreach}}`
 //
 // Block helper designed for looping through posts
-const {hbs, checks} = require('../services/proxy');
+const {checks} = require('../services/proxy');
+const {hbs} = require('../services/rendering');
 
 const _ = require('lodash');
 const logging = require('@tryghost/logging');

core/frontend/helpers/get.js

@@ -1,7 +1,8 @@
 // # Get Helper
 // Usage: `{{#get "posts" limit="5"}}`, `{{#get "tags" limit="all"}}`
 // Fetches data from the API
-const {config, hbs, api, prepareContextResource} = require('../services/proxy');
+const {config, api, prepareContextResource} = require('../services/proxy');
+const {hbs} = require('../services/rendering');
 
 const logging = require('@tryghost/logging');
 const errors = require('@tryghost/errors');

core/frontend/helpers/ghost_foot.js

@@ -2,7 +2,8 @@
 // Usage: `{{ghost_foot}}`
 //
 // Outputs scripts and other assets at the bottom of a Ghost theme
-const {SafeString, settingsCache} = require('../services/proxy');
+const {settingsCache} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 const _ = require('lodash');
 
 // We use the name ghost_foot to match the helper for consistency:

core/frontend/helpers/ghost_head.js

@@ -2,7 +2,8 @@
 // Usage: `{{ghost_head}}`
 //
 // Outputs scripts and other assets at the top of a Ghost theme
-const {metaData, escapeExpression, SafeString, settingsCache, config, blogIcon, urlUtils, labs} = require('../services/proxy');
+const {metaData, settingsCache, config, blogIcon, urlUtils, labs} = require('../services/proxy');
+const {escapeExpression, SafeString} = require('../services/rendering');
 
 const logging = require('@tryghost/logging');
 const _ = require('lodash');

core/frontend/helpers/lang.js

@@ -12,7 +12,7 @@
 // Language tags in HTML and XML
 // https://www.w3.org/International/articles/language-tags/
 
-const {SafeString} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 
 module.exports = function lang(options) {
     const locale = options.data.site.locale;

core/frontend/helpers/link.js

@@ -1,5 +1,6 @@
 // # link helper
-const {config, SafeString, localUtils} = require('../services/proxy');
+const {config} = require('../services/proxy');
+const {SafeString, localUtils} = require('../services/rendering');
 
 const _ = require('lodash');
 const errors = require('@tryghost/errors');

core/frontend/helpers/link_class.js

@@ -1,5 +1,6 @@
 // # link_class helper
-const {config, SafeString, localUtils} = require('../services/proxy');
+const {config} = require('../services/proxy');
+const {SafeString, localUtils} = require('../services/rendering');
 
 const _ = require('lodash');
 const errors = require('@tryghost/errors');

core/frontend/helpers/match.js

@@ -1,4 +1,5 @@
-const {SafeString, labs} = require('../services/proxy');
+const {labs} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 
 const logging = require('@tryghost/logging');
 const tpl = require('@tryghost/tpl');

core/frontend/helpers/navigation.js

@@ -1,7 +1,7 @@
 // ### Navigation Helper
 // `{{navigation}}`
 // Outputs navigation menu of static urls
-const {SafeString, templates, hbs} = require('../services/proxy');
+const {SafeString, templates, hbs} = require('../services/rendering');
 
 const errors = require('@tryghost/errors');
 const tpl = require('@tryghost/tpl');

core/frontend/helpers/pagination.js

@@ -1,7 +1,7 @@
 // ### Pagination Helper
 // `{{pagination}}`
 // Outputs previous and next buttons, along with info about the current page
-const {templates, hbs} = require('../services/proxy');
+const {templates, hbs} = require('../services/rendering');
 
 const errors = require('@tryghost/errors');
 const tpl = require('@tryghost/tpl');

core/frontend/helpers/plural.js

@@ -9,7 +9,7 @@
 // The 2nd argument is the string that will be output if the variable's value is 0
 // The 3rd argument is the string that will be output if the variable's value is 1
 // The 4th argument is the string that will be output if the variable's value is 2+
-const {SafeString} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 
 const errors = require('@tryghost/errors');
 const tpl = require('@tryghost/tpl');

core/frontend/helpers/post_class.js

@@ -2,7 +2,7 @@
 // Usage: `{{post_class}}`
 //
 // Output classes for the body element
-const {SafeString} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 
 // We use the name post_class to match the helper for consistency:
 module.exports = function post_class() { // eslint-disable-line camelcase

core/frontend/helpers/prev_post.js

@@ -2,7 +2,8 @@
 //  Example usages
 // `{{#prev_post}}<a href ="{{url}}>previous post</a>{{/prev_post}}'
 // `{{#next_post}}<a href ="{{url absolute="true">next post</a>{{/next_post}}'
-const {api, hbs, checks} = require('../services/proxy');
+const {api, checks} = require('../services/proxy');
+const {hbs} = require('../services/rendering');
 
 const logging = require('@tryghost/logging');
 const tpl = require('@tryghost/tpl');

core/frontend/helpers/products.js

@@ -3,7 +3,8 @@
 //
 // Returns a string of the products with access to the post.
 // By default, products are separated by commas.
-const {SafeString, labs} = require('../services/proxy');
+const {labs} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 
 const nql = require('@nexes/nql');
 const isString = require('lodash/isString');

core/frontend/helpers/reading_time.js

@@ -10,9 +10,10 @@
 //
 // Returns estimated reading time for post
 
-const {SafeString, checks} = require('../services/proxy');
+const {checks} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 
-const calculateReadingTime = require('@tryghost/helpers').readingTime;
+const {readingTime: calculateReadingTime} = require('@tryghost/helpers');
 
 module.exports = function reading_time(options) {// eslint-disable-line camelcase
     options = options || {};

core/frontend/helpers/t.js

@@ -10,7 +10,7 @@
 // because often other helpers need that (t) returns a string to be able to work as subexpression; e.g.:
 // {{tags prefix=(t " on ")}}
 
-const {themeI18n} = require('../services/proxy');
+const {themeI18n} = require('../services/rendering');
 
 module.exports = function t(text, options) {
     const bindings = {};

core/frontend/helpers/tags.js

@@ -5,7 +5,8 @@
 // By default, tags are separated by commas.
 //
 // Note that the standard {{#each tags}} implementation is unaffected by this helper
-const {urlService, SafeString, escapeExpression, templates} = require('../services/proxy');
+const {urlService} = require('../services/proxy');
+const {SafeString, escapeExpression, templates} = require('../services/rendering');
 
 const isString = require('lodash/isString');
 const ghostHelperUtils = require('@tryghost/helpers').utils;

core/frontend/helpers/title.js

@@ -3,7 +3,7 @@
 //
 // Overrides the standard behaviour of `{[title}}` to ensure the content is correctly escaped
 
-const {SafeString, escapeExpression} = require('../services/proxy');
+const {SafeString, escapeExpression} = require('../services/rendering');
 
 module.exports = function title() {
     return new SafeString(escapeExpression(this.title || ''));

core/frontend/helpers/twitter_url.js

@@ -2,7 +2,8 @@
 // Usage: `{{twitter_url}}` or `{{twitter_url author.twitter}}`
 //
 // Output a url for a twitter username
-const {socialUrls, localUtils} = require('../services/proxy');
+const {socialUrls} = require('../services/proxy');
+const {localUtils} = require('../services/rendering');
 
 // We use the name twitter_url to match the helper for consistency:
 module.exports = function twitter_url(username, options) { // eslint-disable-line camelcase

core/frontend/helpers/url.js

@@ -4,7 +4,8 @@
 // Returns the URL for the current object scope i.e. If inside a post scope will return post permalink
 // `absolute` flag outputs absolute URL, else URL is relative
 
-const {SafeString, metaData} = require('../services/proxy');
+const {metaData} = require('../services/proxy');
+const {SafeString} = require('../services/rendering');
 
 const {getMetaDataUrl} = metaData;
 

core/frontend/services/proxy.js

@@ -1,25 +1,11 @@
 // This file contains everything that the helpers and frontend apps require from the core of Ghost
-const hbs = require('./theme-engine/engine');
 const settingsCache = require('../../shared/settings-cache');
 const config = require('../../shared/config');
 
+// Require from the rendering framework
+const {SafeString} = require('./rendering');
+
 module.exports = {
-    /**
-     * Section one: Frontend Framework
-     * These all belong to the frontend rendering layer
-     */
-    hbs: hbs,
-    SafeString: hbs.SafeString,
-    escapeExpression: hbs.escapeExpression,
-    // The local template thing, should this be merged with the channels one?
-    templates: require('./theme-engine/handlebars/template'),
-
-    // Theme i18n is separate to common i18n
-    themeI18n: require('./theme-engine/i18n'),
-
-    // TODO: these need a more sensible home
-    localUtils: require('./theme-engine/handlebars/utils'),
-
     /**
      * Section two: data manipulation
      * Stuff that modifies API data (SDK layer)
@@ -32,7 +18,7 @@ module.exports = {
         (Array.isArray(data) ? data : [data]).forEach((resource) => {
             // feature_image_caption contains HTML, making it a SafeString spares theme devs from triple-curlies
             if (resource.feature_image_caption) {
-                resource.feature_image_caption = new hbs.SafeString(resource.feature_image_caption);
+                resource.feature_image_caption = new SafeString(resource.feature_image_caption);
             }
         });
     },

core/frontend/services/rendering.js

@@ -0,0 +1,24 @@
+/**
+ * This is a loose concept of a frontend rendering framework
+ * Note: everything here gets deep-required from the theme-engine
+ * This indicates that the theme engine is a set of services, rather than a single service
+ * and could do with a refactor.
+ *
+ * This at least keeps the deep requires in a single place.
+ */
+
+const hbs = require('./theme-engine/engine');
+
+module.exports = {
+    hbs: hbs,
+    SafeString: hbs.SafeString,
+    escapeExpression: hbs.escapeExpression,
+    // The local template thing, should this be merged with the channels one?
+    templates: require('./theme-engine/handlebars/template'),
+
+    // Theme i18n is separate to common i18n
+    themeI18n: require('./theme-engine/i18n'),
+
+    // TODO: these need a more sensible home
+    localUtils: require('./theme-engine/handlebars/utils')
+};

test/unit/helpers/get.test.js

@@ -1,7 +1,7 @@
 const should = require('should');
 const sinon = require('sinon');
 const Promise = require('bluebird');
-const {SafeString} = require('../../../core/frontend/services/proxy');
+const {SafeString} = require('../../../core/frontend/services/rendering');
 
 // Stuff we are testing
 const helpers = require('../../../core/frontend/helpers');

test/unit/helpers/ghost_foot.test.js

@@ -1,8 +1,7 @@
 const should = require('should');
 const sinon = require('sinon');
 const helpers = require('../../../core/frontend/helpers');
-const proxy = require('../../../core/frontend/services/proxy');
-const settingsCache = proxy.settingsCache;
+const {settingsCache} = require('../../../core/frontend/services/proxy');
 
 describe('{{ghost_foot}} helper', function () {
     let settingsCacheStub;

test/unit/helpers/ghost_head.test.js

@@ -12,8 +12,7 @@ const imageLib = require('../../../core/server/lib/image');
 const routing = require('../../../core/frontend/services/routing');
 const urlService = require('../../../core/frontend/services/url');
 const helpers = require('../../../core/frontend/helpers');
-const proxy = require('../../../core/frontend/services/proxy');
-const settingsCache = proxy.settingsCache;
+const {settingsCache} = require('../../../core/frontend/services/proxy');
 
 describe('{{ghost_head}} helper', function () {
     let posts = [];

test/unit/services/routing/helpers/format-response.test.js

@@ -1,7 +1,7 @@
 const should = require('should');
 const testUtils = require('../../../../utils');
 const helpers = require('../../../../../core/frontend/services/routing/helpers');
-const {SafeString} = require('../../../../../core/frontend/services/proxy');
+const {SafeString} = require('../../../../../core/frontend/services/rendering');
 
 describe('Unit - services/routing/helpers/format-response', function () {
     let posts;

test/unit/services/theme-engine/handlebars/template.test.js

@@ -1,12 +1,12 @@
 const should = require('should');
 const errors = require('@tryghost/errors');
-const proxy = require('../../../../../core/frontend/services/proxy');
+const {hbs, templates} = require('../../../../../core/frontend/services/rendering');
 
 describe('Helpers Template', function () {
     it('can execute a template', function () {
-        proxy.hbs.registerPartial('test', '<h1>Hello {{name}}</h1>');
+        hbs.registerPartial('test', '<h1>Hello {{name}}</h1>');
 
-        const safeString = proxy.templates.execute('test', {name: 'world'});
+        const safeString = templates.execute('test', {name: 'world'});
 
         should.exist(safeString);
         safeString.should.have.property('string').and.equal('<h1>Hello world</h1>');
@@ -14,7 +14,7 @@ describe('Helpers Template', function () {
 
     it('will throw an IncorrectUsageError if the partial does not exist', function () {
         should.throws(() => {
-            proxy.templates.execute('non-existent');
+            templates.execute('non-existent');
         }, errors.IncorrectUsageError);
     });
 });