Programmatically invoke eleventy's `.restart()`, or watch variables

[khawkins98]

I've successfully mapped a JS object (like this) and that's working smoothly.

What I'd now like to do is for the 11ty watch to trigger when that javascript changes.

Conceptual example:

myData.js

module.exports = {
  numberOfTweets: somePassedObjectOfTweets.tweetCount
};

Then when somePassedObjectOfTweets changes, I'd like for the 11ty watch to trigger; sort of something like this:

.eleventy.js

Object.observe(somePassedObjectOfTweets, function() {
  trigger11tyWatch();
});

Any ideas?

My workaround

For the time being I'm just doing this:

.eleventy.js

const touch = require("touch");
// https://www.npmjs.com/package/touch
Object.observe(somePassedObjectOfTweets, function() {
   touch('src/site/_data/myJsDataFile.js');
});

[chrissy-dev]

I'm confused, sorry. Do you need/want to rebuild your site when you post a tweet?
What would cause the contents of your myData.js file to change?

[khawkins98]

In this case I have a parallel node process running (component library: fractal) and the object of components is exposed to 11ty via data.js file, however I need 11ty to take note when that object updates.

The data object is successfully passed on fractal update, however 11ty doesn't trigger its watch rebuild.

So for now it's working by "touching" a watched folder on fractal update.

It would be great if there was some kind of rebuild function available inside eleventy.js

[khawkins98]

If that's still not clear, here's my commit with my working touch workaround: visual-framework/vf-demo-design-system@69f404d

[Ryuno-Ki]

I'm wondering, whether it's the right approach.
I mean, eleventy is a SSG.
I think, what you're looking for is something, which invokes a command whenever a certain event is received.
I'm pretty sure, that there is such a library.
The command would then trigger a build.

[chrissy-dev]

@Ryuno-Ki I agree, @khawkins98 I feel your approach is perhaps trying to use the 11ty config as a task runner. I'd probably use gulp to watch the files then trigger an eleventy build when your files have changed.

[khawkins98]

The static build aspect is working fine, but what I'd like to do is extend the local development "watch" style behaviour. Much the same as if a process pulled in a Twitter feed to a local json file, then I'd want eleventy's watch to invoke.

But in my case it's not a file system that's been updated, but a variable.

Looking at the code for eleventy there are probably two fundamental things that are stopping this:

• the current watch behaviour is designed for filesystem changes, and I want to observe a data object
• alternatively, I can bypass eleventy's watch and create my own data object observer. But that falls short as eleventy is not structured to allow for easy access to .restart(), at least not without locally maintaining my own cmd.js (please do let me know if I'm off there)

That said there are two workarounds that would easily work in my case:

• Export the data object to the file system where 11ty would observe the change
• Carry on with the previously mentioned touch()-based hack that triggers the watch event

At any rate, my original ask seems clearly not in scope.

[khawkins98]

Updated the title again for future googling.

[Ryuno-Ki]

Hm … the other day, I was wondering, whether some ideas could be stolen from harp.js, which can be used as middleware (in, e.g., Express.js).

As a more broad concept behind this …
@zachleat Shall I open a new issue for this?