grille/lib/storage/redis.js

Simple CMS using Google Spreadsheets

'use strict';

var redis = require('redis');

/**
 * Sample storage engine for Grille CMS
 */
var RedisGrilleStorage = function(config) {
  if (!config) {
    config = {};
  }

  this.host = config.host || '127.0.0.1';
  this.port = config.port || 6379;

  this.keys = {};
  this.keys.current = config.current || 'grille-current';
  this.keys.collection = config.collection || 'grille-content';

  this.redis = redis.createClient(this.port, this.host, {});
};

/**
 * Saves this version of CMS data
 */
RedisGrilleStorage.prototype.save = function(version, data, callback) {
  if (!version) {
    throw new Error("Invalid Version for RedisGrilleStorage.save()!");
  }

  data = JSON.stringify(data);

  this.redis.hset(this.keys.collection, version, data, function(err) {
    if (err) {
      return callback(err);
    }

    callback(null);
  });
};

/**
 * Sets the current version number
 */
RedisGrilleStorage.prototype.setDefaultVersion = function(version, callback) {
  if (!version) {
    throw new Error("Invalid Version for RedisGrilleStorage.setDefaultVersion()!");
  }

  this.redis.set(this.keys.current, version, function(err) {
    if (err) {
      return callback(err);
    }

    callback(null);
  });
};

/**
 * Returns the current version number
 */
RedisGrilleStorage.prototype.getDefaultVersion = function(callback) {
  this.redis.get(this.keys.current, function(err, version) {
    if (err) {
      return callback(err);
    }

    if (!version) {
      return callback(new Error("Cannot get default version"));
    }

    callback(null, version);
  });
};

/**
 * Loads CMS data using the specified version number
 */
RedisGrilleStorage.prototype.load = function(version, callback) {
  if (!version) {
    throw new Error("Invalid Version for RedisGrilleStorage.load()!");
  }

  this.redis.hget(this.keys.collection, version, function(err, data) {
    if (err) {
      return callback(err);
    }

    if (!data) {
      return callback(new Error("Cannot find data matching this version number"));
    }

    data = JSON.parse(data);

    callback(null, data);
  });
};

/**
 * Loads the current version of CMS data
 * load(getDefaultVersion())
 */
RedisGrilleStorage.prototype.loadDefaultVersion = function(callback) {
  var self = this;

  this.getDefaultVersion(function(err, version) {
    if (err) {
      return callback(err);
    }

    self.load(version, function(err, data) {
      if (err) {
        return callback(err);
      }

      callback(null, data, version);
    });
  });
};

/**
 * Gets a list of CMS versions (not guaranteed to be in order
 */
RedisGrilleStorage.prototype.list = function(callback) {
  this.redis.hkeys(this.keys.collection, function(err, versions) {
    if (err) {
      return callback(err);
    }

    callback(null, versions);
  });
};

/**
 * Cleans everything up
 */
RedisGrilleStorage.prototype.clear = function(callback) {
  this.redis.multi()
    .del(this.keys.collection)
    .del(this.keys.current)
    .exec(callback);
};

module.exports = RedisGrilleStorage;