Removed use of i18n from helpers in favour of tpl

- i18n is an old pattern that failed
- we are slowly replacing i18n with the tpl helper

core/frontend/helpers/asset.js

@@ -2,16 +2,20 @@
 // Usage: `{{asset "css/screen.css"}}`
 //
 // Returns the path to the specified asset.
-const {SafeString, metaData, errors, i18n} = require('../services/proxy');
+const {SafeString, metaData, errors, tpl} = require('../services/proxy');
 const get = require('lodash/get');
 const {getAssetUrl} = metaData;
 
+const messages = {
+    pathIsRequired: 'The {{asset}} helper must be passed a path'
+};
+
 module.exports = function asset(path, options) {
     const hasMinFile = get(options, 'hash.hasMinFile');
 
     if (!path) {
         throw new errors.IncorrectUsageError({
-            message: i18n.t('warnings.helpers.asset.pathIsRequired')
+            message: tpl(messages.pathIsRequired)
         });
     }
 

core/frontend/helpers/cancel_link.js

@@ -6,13 +6,17 @@
 //
 // Defaults to class="cancel-subscription-link" errorClass="cancel-subscription-error" cancelLabel="Cancel subscription" continueLabel="Continue subscription"
 
-const {templates, errors, i18n, labs} = require('../services/proxy');
+const {templates, errors, tpl, labs} = require('../services/proxy');
+
+const messages = {
+    invalidData: 'The {{cancel_link}} helper was used outside of a subscription context. See https://ghost.org/docs/themes/members/#cancel-links.'
+};
 
 function cancel_link(options) { // eslint-disable-line camelcase
     let truncateOptions = (options || {}).hash || {};
 
     if (this.id === undefined || this.cancel_at_period_end === undefined) {
-        throw new errors.IncorrectUsageError({message: i18n.t('warnings.helpers.cancel_link.invalidData')});
+        throw new errors.IncorrectUsageError({message: tpl(messages.invalidData)});
     }
 
     const data = {

core/frontend/helpers/foreach.js

@@ -3,13 +3,17 @@
 //
 // Block helper designed for looping through posts
 const _ = require('lodash');
-const {logging, i18n, hbs, checks} = require('../services/proxy');
+const {logging, tpl, hbs, checks} = require('../services/proxy');
 const {Utils: hbsUtils, handlebars: {createFrame}} = hbs;
 const ghostHelperUtils = require('@tryghost/helpers').utils;
 
+const messages = {
+    iteratorNeeded: 'Need to pass an iterator to {{#foreach}}'
+};
+
 module.exports = function foreach(items, options) {
     if (!options) {
-        logging.warn(i18n.t('warnings.helpers.foreach.iteratorNeeded'));
+        logging.warn(tpl(messages.iteratorNeeded));
     }
 
     if (hbsUtils.isFunction(items)) {

core/frontend/helpers/get.js

@@ -1,11 +1,16 @@
 // # Get Helper
 // Usage: `{{#get "posts" limit="5"}}`, `{{#get "tags" limit="all"}}`
 // Fetches data from the API
-const {config, logging, errors, i18n, hbs, api, prepareContextResource} = require('../services/proxy');
+const {config, logging, errors, tpl, hbs, api, prepareContextResource} = require('../services/proxy');
 const _ = require('lodash');
 const Promise = require('bluebird');
 const jsonpath = require('jsonpath');
 
+const messages = {
+    mustBeCalledAsBlock: 'The {{{helperName}}} helper must be called as a block. E.g. {{#{helperName}}}...{{/{helperName}}}',
+    invalidResource: 'Invalid resource given to get helper'
+};
+
 const createFrame = hbs.handlebars.createFrame;
 
 const RESOURCES = {
@@ -121,13 +126,13 @@ module.exports = function get(resource, options) {
     let returnedRowsCount;
 
     if (!options.fn) {
-        data.error = i18n.t('warnings.helpers.mustBeCalledAsBlock', {helperName: 'get'});
+        data.error = tpl(messages.mustBeCalledAsBlock, {helperName: 'get'});
         logging.warn(data.error);
         return Promise.resolve();
     }
 
     if (!RESOURCES[resource]) {
-        data.error = i18n.t('warnings.helpers.get.invalidResource');
+        data.error = tpl(messages.invalidResource);
         logging.warn(data.error);
         return Promise.resolve(options.inverse(self, {data: data}));
     }

core/frontend/helpers/has.js

@@ -4,9 +4,13 @@
 //
 // Checks if a post has a particular property
 
-const {logging, i18n} = require('../services/proxy');
+const {logging, tpl} = require('../services/proxy');
 const _ = require('lodash');
-const validAttrs = ['tag', 'author', 'slug','visibility', 'id', 'number', 'index', 'any', 'all'];
+const validAttrs = ['tag', 'author', 'slug', 'visibility', 'id', 'number', 'index', 'any', 'all'];
+
+const messages = {
+    invalidAttribute: 'Invalid or no attribute given to has helper'
+};
 
 function handleCount(ctxAttr, data) {
     if (!data || !_.isFinite(data.length)) {
@@ -155,7 +159,7 @@ module.exports = function has(options) {
     let result;
 
     if (_.isEmpty(attrs)) {
-        logging.warn(i18n.t('warnings.helpers.has.invalidAttribute'));
+        logging.warn(tpl(messages.invalidAttribute));
         return;
     }
 

core/frontend/helpers/img_url.js

@@ -9,21 +9,25 @@
 
 const url = require('url');
 const _ = require('lodash');
-const {urlUtils, logging, i18n} = require('../services/proxy');
+const {urlUtils, logging, tpl} = require('../services/proxy');
+
+const messages = {
+    attrIsRequired: 'Attribute is required e.g. {{img_url feature_image}}'
+};
 
 const STATIC_IMAGE_URL_PREFIX = `${urlUtils.STATIC_IMAGE_URL_PREFIX}`;
 
 module.exports = function imgUrl(requestedImageUrl, options) {
     // CASE: if no url is passed, e.g. `{{img_url}}` we show a warning
     if (arguments.length < 2) {
-        logging.warn(i18n.t('warnings.helpers.img_url.attrIsRequired'));
+        logging.warn(tpl(messages.attrIsRequired));
         return;
     }
 
     // CASE: if url is passed, but it is undefined, then the attribute was
     // an unknown value, e.g. {{img_url feature_img}} and we also show a warning
     if (requestedImageUrl === undefined) {
-        logging.warn(i18n.t('warnings.helpers.img_url.attrIsRequired'));
+        logging.warn(tpl(messages.attrIsRequired));
         return;
     }
 

core/frontend/helpers/is.js

@@ -1,16 +1,20 @@
 // # Is Helper
 // Usage: `{{#is "paged"}}`, `{{#is "index, paged"}}`
 // Checks whether we're in a given context.
-const {logging, i18n} = require('../services/proxy');
+const {logging, tpl} = require('../services/proxy');
 const _ = require('lodash');
 
+const messages = {
+    invalidAttribute: 'Invalid or no attribute given to is helper'
+};
+
 module.exports = function is(context, options) {
     options = options || {};
 
     const currentContext = options.data.root.context;
 
     if (!_.isString(context)) {
-        logging.warn(i18n.t('warnings.helpers.is.invalidAttribute'));
+        logging.warn(tpl(messages.invalidAttribute));
         return;
     }
 

core/frontend/helpers/link.js

@@ -1,8 +1,12 @@
 // # link helper
 const _ = require('lodash');
-const {config, SafeString, errors, i18n, localUtils} = require('../services/proxy');
+const {config, SafeString, errors, tpl, localUtils} = require('../services/proxy');
 const {buildLinkClasses} = localUtils;
 
+const messages = {
+    hrefIsRequired: 'The {{#link}}{{/link}} helper requires an href="" attribute.'
+};
+
 const managedAttributes = ['href', 'class', 'activeClass', 'parentActiveClass'];
 
 function _formatAttrs(attributes) {
@@ -25,7 +29,7 @@ module.exports = function link(options) {
     // If there is no href provided, this is theme dev error, so we throw an error to make this clear.
     if (!_.has(options.hash, 'href')) {
         throw new errors.IncorrectUsageError({
-            message: i18n.t('warnings.helpers.link.hrefIsRequired')
+            message: tpl(messages.hrefIsRequired)
         });
     }
     // If the href attribute is empty, this is probably a dynamic data problem, hard for theme devs to track down

core/frontend/helpers/link_class.js

@@ -1,8 +1,12 @@
 // # link_class helper
 const _ = require('lodash');
-const {config, SafeString, errors, i18n, localUtils} = require('../services/proxy');
+const {config, SafeString, errors, tpl, localUtils} = require('../services/proxy');
 const {buildLinkClasses} = localUtils;
 
+const messages = {
+    forIsRequired: 'The {{link_class}} helper requires a for="" attribute.'
+};
+
 module.exports = function link_class(options) { // eslint-disable-line camelcase
     options = options || {};
     options.hash = options.hash || {};
@@ -11,7 +15,7 @@ module.exports = function link_class(options) { // eslint-disable-line camelcase
     // If there is no for provided, this is theme dev error, so we throw an error to make this clear.
     if (!_.has(options.hash, 'for')) {
         throw new errors.IncorrectUsageError({
-            message: i18n.t('warnings.helpers.link_class.forIsRequired')
+            message: tpl(messages.forIsRequired)
         });
     }
 

core/frontend/helpers/match.js

@@ -1,6 +1,10 @@
-const {logging, i18n, SafeString, labs} = require('../services/proxy');
+const {logging, tpl, SafeString, labs} = require('../services/proxy');
 const _ = require('lodash');
 
+const messages = {
+    invalidAttribute: 'Invalid or no attribute given to match helper'
+};
+
 /**
  * This is identical to the built-in if helper, except inverse/fn calls are replaced with false/true
  * https://github.com/handlebars-lang/handlebars.js/blob/19bdace85a8d0bc5ed3a4dec4071cb08c8d003f2/lib/handlebars/helpers/if.js#L9-L20
@@ -58,7 +62,7 @@ function match(...attrs) {
     let result;
 
     if (_.isEmpty(attrs)) {
-        logging.warn(i18n.t('warnings.helpers.has.invalidAttribute'));
+        logging.warn(tpl(messages.invalidAttribute));
         return;
     }
 
@@ -68,7 +72,7 @@ function match(...attrs) {
     } else if (attrs.length === 3) {
         result = handleMatch(attrs[0], attrs[1], attrs[2], options);
     } else {
-        logging.warn(i18n.t('warnings.helpers.has.invalidAttribute'));
+        logging.warn(tpl(messages.invalidAttribute));
         return;
     }
 

core/frontend/helpers/navigation.js

@@ -2,9 +2,16 @@
 // `{{navigation}}`
 // Outputs navigation menu of static urls
 
-const {SafeString, i18n, errors, templates, hbs} = require('../services/proxy');
+const {SafeString, tpl, errors, templates, hbs} = require('../services/proxy');
 const {slugify} = require('@tryghost/string');
 const _ = require('lodash');
+
+const messages = {
+    invalidData: 'navigation data is not an object or is a function',
+    valuesMustBeDefined: 'All values must be defined for label, url and current',
+    valuesMustBeString: 'Invalid value, Url and Label must be strings'
+};
+
 const createFrame = hbs.handlebars.createFrame;
 
 module.exports = function navigation(options) {
@@ -25,7 +32,7 @@ module.exports = function navigation(options) {
 
     if (!_.isObject(navigationData) || _.isFunction(navigationData)) {
         throw new errors.IncorrectUsageError({
-            message: i18n.t('warnings.helpers.navigation.invalidData')
+            message: tpl(messages.invalidData)
         });
     }
 
@@ -33,7 +40,7 @@ module.exports = function navigation(options) {
         return (_.isUndefined(e.label) || _.isUndefined(e.url));
     }).length > 0) {
         throw new errors.IncorrectUsageError({
-            message: i18n.t('warnings.helpers.navigation.valuesMustBeDefined')
+            message: tpl(messages.valuesMustBeDefined)
         });
     }
 
@@ -43,7 +50,7 @@ module.exports = function navigation(options) {
             (!_.isNull(e.url) && !_.isString(e.url)));
     }).length > 0) {
         throw new errors.IncorrectUsageError({
-            message: i18n.t('warnings.helpers.navigation.valuesMustBeString')
+            message: tpl(messages.valuesMustBeString)
         });
     }
 

core/frontend/helpers/pagination.js

@@ -2,8 +2,16 @@
 // `{{pagination}}`
 // Outputs previous and next buttons, along with info about the current page
 
-const {errors, i18n, templates, hbs} = require('../services/proxy');
+const {errors, tpl, templates, hbs} = require('../services/proxy');
 const _ = require('lodash');
+
+const messages = {
+    invalidData: 'The {{pagination}} helper was used outside of a paginated context. See https://ghost.org/docs/themes/helpers/pagination/.',
+    valuesMustBeDefined: 'All values must be defined for page, pages, limit and total',
+    nextPrevValuesMustBeNumeric: 'Invalid value, Next/Prev must be a number',
+    valuesMustBeNumeric: 'Invalid value, check page, pages, limit and total are numbers'
+};
+
 const createFrame = hbs.handlebars.createFrame;
 
 module.exports = function pagination(options) {
@@ -14,7 +22,7 @@ module.exports = function pagination(options) {
     if (!_.isObject(this.pagination) || _.isFunction(this.pagination)) {
         throw new errors.IncorrectUsageError({
             level: 'normal',
-            message: i18n.t('warnings.helpers.pagination.invalidData'),
+            message: tpl(messages.invalidData),
             help: 'https://ghost.org/docs/themes/helpers/pagination/'
         });
     }
@@ -22,20 +30,20 @@ module.exports = function pagination(options) {
     if (_.isUndefined(this.pagination.page) || _.isUndefined(this.pagination.pages) ||
         _.isUndefined(this.pagination.total) || _.isUndefined(this.pagination.limit)) {
         throw new errors.IncorrectUsageError({
-            message: i18n.t('warnings.helpers.pagination.valuesMustBeDefined')
+            message: tpl(messages.valuesMustBeDefined)
         });
     }
 
     if ((!_.isNull(this.pagination.next) && !_.isNumber(this.pagination.next)) ||
         (!_.isNull(this.pagination.prev) && !_.isNumber(this.pagination.prev))) {
         throw new errors.IncorrectUsageError({
-            message: i18n.t('warnings.helpers.pagination.nextPrevValuesMustBeNumeric')
+            message: tpl(messages.nextPrevValuesMustBeNumeric)
         });
     }
 
     if (!_.isNumber(this.pagination.page) || !_.isNumber(this.pagination.pages) ||
         !_.isNumber(this.pagination.total) || !_.isNumber(this.pagination.limit)) {
-        throw new errors.IncorrectUsageError({message: i18n.t('warnings.helpers.pagination.valuesMustBeNumeric')});
+        throw new errors.IncorrectUsageError({message: tpl(messages.valuesMustBeNumeric)});
     }
 
     // CASE: The pagination helper should have access to the pagination properties at the top level.

core/frontend/helpers/plural.js

@@ -10,14 +10,18 @@
 // 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 {errors, i18n, SafeString} = require('../services/proxy');
+const {errors, tpl, SafeString} = require('../services/proxy');
 const isUndefined = require('lodash/isUndefined');
 
+const messages = {
+    valuesMustBeDefined: 'All values must be defined for empty, singular and plural'
+};
+
 module.exports = function plural(number, options) {
     if (isUndefined(options.hash) || isUndefined(options.hash.empty) ||
         isUndefined(options.hash.singular) || isUndefined(options.hash.plural)) {
         throw new errors.IncorrectUsageError({
-            message: i18n.t('warnings.helpers.plural.valuesMustBeDefined')
+            message: tpl(messages.valuesMustBeDefined)
         });
     }
 

core/frontend/helpers/prev_post.js

@@ -3,11 +3,15 @@
 // `{{#prev_post}}<a href ="{{url}}>previous post</a>{{/prev_post}}'
 // `{{#next_post}}<a href ="{{url absolute="true">next post</a>{{/next_post}}'
 
-const {logging, i18n, api, hbs, checks} = require('../services/proxy');
+const {logging, tpl, api, hbs, checks} = require('../services/proxy');
 const get = require('lodash/get');
 const Promise = require('bluebird');
 const moment = require('moment');
 
+const messages = {
+    mustBeCalledAsBlock: 'The {{{helperName}}} helper must be called as a block. E.g. {{#{helperName}}}...{{/{helperName}}}'
+};
+
 const createFrame = hbs.handlebars.createFrame;
 
 const buildApiOptions = function buildApiOptions(options, post) {
@@ -78,7 +82,7 @@ module.exports = function prevNext(options) {
 
     // Guard against incorrect usage of the helpers
     if (!options.fn || !options.inverse) {
-        data.error = i18n.t('warnings.helpers.mustBeCalledAsBlock', {helperName: options.name});
+        data.error = tpl(messages.mustBeCalledAsBlock, {helperName: options.name});
         logging.warn(data.error);
         return Promise.resolve();
     }

core/frontend/helpers/price.js

@@ -11,9 +11,14 @@
 // Returns amount equal to the dominant denomintation of the currency.
 // For example, if 2100 is passed, it will return 21.
 const isNumber = require('lodash/isNumber');
-const {errors, i18n} = require('../services/proxy');
+const {errors, tpl} = require('../services/proxy');
 const _ = require('lodash');
 
+const messages = {
+    attrIsRequired: 'Attribute is required e.g. {{price plan.amount}}',
+    attrMustBeNumeric: 'Attribute value should be a number'
+};
+
 function formatter({amount, currency, numberFormat = 'short', currencyFormat = 'symbol', locale}) {
     const formatterOptions = {
         style: 'currency',
@@ -77,20 +82,20 @@ module.exports = function price(planOrAmount, options) {
     // CASE: if no amount is passed, e.g. `{{price}}` we throw an error
     if (arguments.length < 2) {
         throw new errors.IncorrectUsageError({
-            message: i18n.t('warnings.helpers.price.attrIsRequired')
+            message: tpl(messages.attrIsRequired)
         });
     }
 
     // CASE: if amount is passed, but it is undefined we throw an error
     if (amount === undefined) {
         throw new errors.IncorrectUsageError({
-            message: i18n.t('warnings.helpers.price.attrIsRequired')
+            message: tpl(messages.attrIsRequired)
         });
     }
 
     if (!isNumber(amount)) {
         throw new errors.IncorrectUsageError({
-            message: i18n.t('warnings.helpers.price.attrMustBeNumeric')
+            message: tpl(messages.attrMustBeNumeric)
         });
     }
 

core/frontend/services/proxy.js

@@ -3,6 +3,7 @@
 // We can later refactor to enforce this something like we did in apps
 const hbs = require('./theme-engine/engine');
 const errors = require('@tryghost/errors');
+const tpl = require('@tryghost/tpl');
 
 const i18n = require('../../shared/i18n');
 const logging = require('@tryghost/logging');
@@ -29,7 +30,9 @@ module.exports = {
 
     // These 3 are kind of core and required all the time
     errors,
+    // @deprecated
     i18n,
+    tpl,
     logging,
 
     // Theme i18n is separate to common i18n