Ghost Kudos Plugin Example

index.js

var fs = require('fs'),
    path = require('path'),
    _ = require('underscore'),
    when = require('when'),
    express = require('express'),
    GhostPlugin = require('../../../core/server/plugins/GhostPlugin'),
    knex = require('../../../core/server/models/base').Knex,
    KudosPlugin;

KudosPlugin = function (ghost) {
    _.bindAll(this, "addKudosToPost");

    var templateContents = fs.readFileSync(path.join(__dirname, 'assets', 'kudos.tpl')).toString();

    this.htmlTemplate = _.template(templateContents);

    GhostPlugin.call(this, ghost);
};

_.extend(KudosPlugin.prototype, GhostPlugin.prototype);

_.extend(KudosPlugin.prototype, {
    install: function () {
        // Create table to hold kudos counts for posts
        return when.all([
            knex.Schema.createTable('posts_kudos', function (t) {
                t.integer('post_id')
                 .primary();

                t.integer('kudos').defaultTo(0);
            })
        ]);
    },

    uninstall: function () {
        // Drop our table to hold kudos counts
        return when.all([
            knex.Schema.dropTableIfExists('posts_kudos')
        ]);

        // TODO: How do I unregister the scripts folder and routes?
    },

    activate: function () {
        var self = this;

        // Register the assets folder as /plugins/Kudos
        this.app.server.use("/plugins/kudos/assets", express.static(path.join(__dirname, 'assets')));
        
        // Register the route for incrementing kudos
        this.app.server.post("/plugins/kudos/api/", function (req, res) {
            // TODO: Request throttling or something?
            var postId = req.param('postId', 0);

            if (!postId) {
                return res.send(404, "Post Not Found with id " + postId);
            }

            self.incrementPostKudos(postId).then(function () {
                res.json({ success: true });
            }, function (e) {
                res.json({ error: e.message });
            });
        });
        
        // Add the css reference for our kudos functionality
        this.app.registerFilter("ghost_head", this.addCSSReference);
        // Add the script reference for our kudos functionality
        this.app.registerFilter("ghost_foot", this.addScriptReference);
        // Add the html for the kudos view to the bottom of the post
        this.app.registerFilter("prePostsRender", this.addKudosToPost);

        // TODO: Would be nice to have a filter for when a post is created, so that we could insert the post_kudos default row
    },

    deactivate: function () {
        // Add the css reference for our kudos functionality
        this.app.unregisterFilter("ghost_head", this.addCSSReference);
        // Add the script reference for our kudos functionality
        this.app.unregisterFilter("ghost_foot", this.addScriptReference);
        // Add the html for the kudos view to the bottom of the post
        this.app.unregisterFilter("prePostsRender", this.addKudosToPost);
    },

    incrementPostKudos: function (postId) {

        return knex('posts_kudos').increment('kudos', 1)
            .where('post_id', postId);
    },

    addKudosToPost: function (post) {
        if (_.isArray(post)) {
            // Don't do anything on the list view, just for single posts
            return post;
        }

        return this.addKudosContent(post);
    },

    addCSSReference: function (styles) {
        styles.push('<link rel="stylesheet" type="text/css" href="/plugins/kudos/assets/kudos.css">');

        return styles;
    },

    addScriptReference: function (scripts) {
        // TODO: Check existing scripts for underscore/backbone already loaded
        // TODO: The underscore and backbone additions could just be there own plugins
        scripts.push('<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.5.2/underscore-min.js"></script>');
        scripts.push('<script src="//cdnjs.cloudflare.com/ajax/libs/backbone.js/1.0.0/backbone-min.js"></script>');
        scripts.push('<script src="/plugins/kudos/assets/kudos.js"></script>');

        return scripts;
    },

    addKudosContent: function (post) {
        var self = this;

        // Add Kudo count from database
        return knex('posts_kudos').select('kudos').where({
            post_id: post.id
        }).then(function (kudosVal) {
            // Default to 0
            var kudosCount = kudosVal && kudosVal.length > 0 ? kudosVal[0].kudos : 0;

            // Add the kudo figure html
            post.html += self.htmlTemplate({
                kudos: kudosCount
            });

            // Add the post id to the Kudo object
            // TODO: This should be made available by Ghost somewhere on the page
            post.html += "\n<script>window.Kudo = window.Kudo || {}; window.Kudo.postId = " + post.id + ";</script>";

            if (kudosVal.length < 1) {
                // Add the default kudos row
                return knex('posts_kudos').insert({
                    post_id: post.id,
                    kudos: 0
                }).then(function () {
                    return when.resolve(post);
                });
            } 

            return when.resolve(post);
            
        }).otherwise(function (e) {
            console.log("Problem loading post kudos", e);
        });
    }
});

module.exports = KudosPlugin;