Added ability for each spec to set readFromCache to true/false

[crwang]

What/Why

• Sometimes we want always to pull back certain data (readFromCache: false), and sometimes we want it to be the default. While, there could be a nested approach, this simplifies how to set it by specifying it in the fetch spec

  How tested

• Wrote tests
• Tested by using it in our own own app

  Example

With this PR:

This would be possible

module.exports = {
    index: function(params, callback) {
        var spec = {
            collection: {
                collection: 'Users',
                params: params
            }
        };
        this.app.fetch(spec, function(err, result) {
            callback(err, result);
        });
    },

    show: function(params, callback) {
        var spec = {
            model: {
                model: 'User',
                params: params,
                readFromCache: false
            },
            repos: {
                collection: 'Repos',
                params: {
                    user: params.login
                },
                readFromCache: true // or omit for default
            }
        };
        this.app.fetch(spec, function(err, result) {
            callback(err, result);
        });
    }
};

As before, always reading from cache is still possible

module.exports = {
    index: function(params, callback) {
        var spec = {
            collection: {
                collection: 'Users',
                params: params
            }
        };
        this.app.fetch(spec, function(err, result) {
            callback(err, result);
        });
    },

    show: function(params, callback) {
        var spec = {
            model: {
                model: 'User',
                params: params               
            },
            repos: {
                collection: 'Repos',
                params: {
                    user: params.login
                }
            }
        };
        this.app.fetch(spec, function(err, result) {
            callback(err, result);
        });
    }
};

As before, never reading from cache is still possible

module.exports = {
    index: function(params, callback) {
        var spec = {
            collection: {
                collection: 'Users',
                params: params
            }
        };
        this.app.fetch(spec, function(err, result) {
            callback(err, result);
        });
    },

    show: function(params, callback) {
        var spec = {
            model: {
                model: 'User',
                params: params
            },
            repos: {
                collection: 'Repos',
                params: {
                    user: params.login
                }
            }
        };
        this.app.fetch(spec, { readFromCache: false }, function(err, result) {
            callback(err, result);
        });
    }
};

[coveralls]

Coverage increased (+0.28%) to 84.5% when pulling 435c7c79994ff21afd7b9f861d357f6cde83f1e7 on crwang:selective-read-from-cache into 5ada76ac4d284008e966037c7e0d86b83190f326 on rendrjs:master.

[pjanuario]

:+1:

[saponifi3d]

Nice! :+1: looks awesome!

I'm probably going to open up a companion PR to this shortly that it'd be awesome if you could take a look at. I'm planning on making it allowing an option to be be passed to constructors as well to save to the cache or not.