add maxAge option for alfy.cache - fixes #3

[SamVerschueren]

• Extended the Conf class and override the set, get and has methods
• Added tests for the cache
• Added documentation regarding the maxAge option

As described in #3, not sure if we should do it with the CacheConf object here, add that option to Conf or create an external CacheConf module to handle this. Will to do either one of those :).

Feel free to suggest improvements of the code or docs.

[SamVerschueren]

The downside of this approach is that it isn't possible to implement a fallback mechanism like I do in alfred-ng2. If the cache is expired, it tries to load the remote data, if that fails it will still load the "old" cache. It would be nice if it was possible to still support that.

---

It actually is possible if you use alfy.cache.store directly, but I don't want everyone to skip the methods. Maybe we should not remove the item if the data is expired and add an extra option to the get method in order to force retrieval.

alfy.cache.set('foo', 'bar', {maxAge: 5000});

await delay(5000);

alfy.cache.get('foo');
//=> undefined

alfy.cache.get('foo', true);
//=> 'bar'

[sindresorhus]

The downside of this approach is that it isn't possible to implement a fallback mechanism like I do in alfred-ng2. If the cache is expired, it tries to load the remote data, if that fails it will still load the "old" cache. It would be nice if it was possible to still support that.

Hmm, maybe we should bundle got here too, and give it ability to cache requests? That would solve your use-case.

[SamVerschueren]

Not sure if we should bundle got into alphy. How would the interface look like then?

alfy.got.get('https://myapi.com/foo/bar.json', {maxAge: 5000}).then(res => {
    console.log(res.body);
    // {foo: 'bar'}
});

[sindresorhus]

@SamVerschueren Fetching from network is a very common operation in Alfred workflows. Would be nice to simplify it. Dependencies are super cheap anyways as they're bundled with the workflow, not npm install'd.

I'm thinking:

alfy.fetch('https://myapi.com/foo/bar.json', {maxAge: 5000}).then(res => {
    console.log(res.body);
    // {foo: 'bar'}
});

And maybe even make {json: true} the default.

To be clear, this is in addition what's currently in this PR, not instead of. Should probably be a separate PR.

[SamVerschueren]

So we would only expose the get method right? Don't think that post makes sense in an Alfred app. Except if the API endpoint expects a post request with alfy.input as post data. Nah, let's just expose the get as fetch. If they have to use post, they can always install got and use got directly instead of via alfy.

Dependencies are super cheap anyways as they're bundled with the workflow

👍

Should probably be a separate PR.

Will add it after this one gets merged.

Is it ok to remove the cached data then when it is expired? Or should we just ignore it without removing it?

[sindresorhus]

So we would only expose the get method right?

Yup.

Except if the API endpoint expects a post request with alfy.input as post data.

Then they can just pass the method option. We just pass the options object to got.

Is it ok to remove the cached data then when it is expired? Or should we just ignore it without removing it?

For alfy.cache, remove it. For alfy.fetch, remove it after successfully getting new data.

[SamVerschueren]

Then they can just pass the method option. We just pass the options object to got.

👍

For alfy.cache, remove it. For alfy.fetch, remove it after successfully getting new data.

👍

[sindresorhus]

Do a alfy.cache.get('foo'); and show the value before the delay too. For clarity.

[SamVerschueren]

I prefer a require at the top instead of await require('delay')(5000). But if you want it inline, I'll fix it :).

[sindresorhus]

Looks superb, as always :)

[SamVerschueren]

Awesome. Super nice to see this land :)! If #6 is implemented, I nearly don't have to do anything anymore in my alfred-ng2 plugin 😆 .