Get helper

closes TryGhost#4439

- adds get helper + tests

core/server/helpers/get.js

@@ -0,0 +1,106 @@
+// # Get Helper
+// Usage: `{{#get "posts" limit="5"}}`, `{{#get "tags" limit="all"}}`
+// Fetches data from the API
+
+var _               = require('lodash'),
+    hbs             = require('express-hbs'),
+    errors          = require('../errors'),
+    api             = require('../api'),
+    jsonpath        = require('jsonpath'),
+
+    resources       = ['posts', 'tags', 'users'],
+    pathAliases     = {
+        'post.tags': 'post.tags[*].slug',
+        'post.author':  'post.author.slug'
+    },
+    get;
+
+function doBrowse(context, options) {
+    var browse = true;
+    if (options.limit && options.limit === 1) {
+        browse = false;
+    }
+
+    if (options.id || options.slug) {
+        browse = false;
+    }
+
+    return browse;
+}
+
+function resolvePaths(data, value) {
+    var regex = /\{\{(.*?)\}\}/g;
+
+    value = value.replace(regex, function (match, path) {
+        var result;
+
+        // Handle tag, author and role aliases
+        path = pathAliases[path] ? pathAliases[path] : path;
+
+        result = jsonpath.query(data, path);
+
+        if (_.isArray(result)) {
+            result = result.join(',');
+        }
+
+        return result;
+    });
+
+    return value;
+}
+
+function parseOptions(data, options) {
+    options = _.omit(options.hash, 'context');
+    if (_.isArray(options.tag)) {
+        options.tag = _.pluck(options.tag, 'slug').join(',');
+    }
+
+    if (_.isString(options.filter)) {
+        options.filter = resolvePaths(data, options.filter);
+    }
+
+    return options;
+}
+
+get = function get(context, options) {
+    options = options || {};
+    options.hash = options.hash || {};
+
+    var self = this,
+        data,
+        apiOptions,
+        apiMethod;
+
+    if (!_.contains(resources, context)) {
+        errors.logWarn('Invalid resource given to get helper');
+        return;
+    }
+
+    if (options.data) {
+        data = hbs.handlebars.createFrame(options.data);
+    }
+
+    // Determine if this is a read or browse
+    apiMethod = doBrowse(context, options) ? api[context].browse : api[context].read;
+    // Parse the options we're going to pass to the API
+    apiOptions = parseOptions(this, options);
+
+    return apiMethod(apiOptions).then(function success(result) {
+        var data = _.merge(self, result);
+        if (_.isEmpty(result[context])) {
+            return options.inverse(self);
+        }
+
+        return options.fn(data, {
+            data: data,
+            blockParams: [result[context]]
+        });
+    }).catch(function error(err) {
+        if (data) {
+            data.error = err.message;
+        }
+        return options.inverse(self, {data: data});
+    });
+};
+
+module.exports = get;

core/server/helpers/index.js

@@ -21,6 +21,7 @@ coreHelpers.date  = require('./date');
 coreHelpers.encode  = require('./encode');
 coreHelpers.excerpt  = require('./excerpt');
 coreHelpers.foreach = require('./foreach');
+coreHelpers.get = require('./get');
 coreHelpers.ghost_foot = require('./ghost_foot');
 coreHelpers.ghost_head = require('./ghost_head');
 coreHelpers.image = require('./image');
@@ -117,6 +118,7 @@ registerHelpers = function (adminHbs) {
     registerAsyncThemeHelper('post_class', coreHelpers.post_class);
     registerAsyncThemeHelper('next_post', coreHelpers.next_post);
     registerAsyncThemeHelper('prev_post', coreHelpers.prev_post);
+    registerAsyncThemeHelper('get', coreHelpers.get);
 
     // Register admin helpers
     registerAdminHelper('asset', coreHelpers.asset);

core/test/unit/server_helpers/get_spec.js

@@ -0,0 +1,63 @@
+/*globals describe, before, beforeEach, afterEach, it*/
+/*jshint expr:true*/
+var should         = require('should'),
+    sinon          = require('sinon'),
+    hbs            = require('express-hbs'),
+    Promise        = require('bluebird'),
+    utils          = require('./utils'),
+
+// Stuff we are testing
+    handlebars     = hbs.handlebars,
+    helpers        = require('../../../server/helpers'),
+    api            = require('../../../server/api');
+
+describe('{{#get}} helper', function () {
+    var sandbox;
+
+    before(function () {
+        utils.loadHelpers();
+    });
+
+    beforeEach(function () {
+        sandbox = sinon.sandbox.create();
+    });
+
+    afterEach(function () {
+        sandbox.restore();
+    });
+
+    it('has loaded get block helper', function () {
+        should.exist(handlebars.helpers.get);
+    });
+
+    describe('posts', function () {
+        var testPostsObj = {
+            posts: [
+                {id: 1}
+            ]
+        };
+        beforeEach(function () {
+            sandbox.stub(api.posts, 'browse', function () {
+                return Promise.resolve(testPostsObj);
+            });
+        });
+
+        it('should handle default posts call', function (done) {
+            var fn = sinon.spy(),
+                inverse = sinon.spy();
+
+            helpers.get.call(
+                {},
+                'posts',
+                {hash: {}, fn: fn, inverse: inverse}
+            ).then(function () {
+                fn.called.should.be.true;
+                fn.firstCall.args[0].should.be.an.Object;
+                fn.firstCall.args[0].should.eql(testPostsObj);
+                inverse.called.should.be.false;
+
+                done();
+            }).catch(done);
+        });
+    });
+});

package.json

@@ -45,6 +45,7 @@
     "html-to-text": "1.3.0",
     "intl": "1.0.0",
     "intl-messageformat": "1.1.0",
+    "jsonpath": "0.1.8",
     "knex": "0.7.3",
     "lodash": "3.10.0",
     "moment": "2.10.3",