helper options

[jonschlinkert]

I think we need to have an option or property somewhere dedicated to helper options.

Currently we're just winging it:

var extend = require('extend-shallow');

template.helper('foo', function (options) {
  var opts = extend({}, this.app.options, options);
  // do stuff
});

It's awesome how easy it is to pass options to helpers, but those options shouldn't be mixed in with the general/global options.

Of course, any helper author can namespace the helper's options however they see fit, but I'd really prefer to have a convention for doing it.

[doowb]

since we're building context for each page, we can do that while binding helpers also... so inside a helper they would be able to access it like...

var extend = require('extend-shallow');

template.helper('foo', function (options) {
  // this.options is only for the specific helper
  var opts = extend({}, this.options, options);
  // do stuff
});

Then when adding options to template for that helper:

template.option({
  foo: {
    bar: 'this is just for the foo helper';
  }
});

And in our bind logic, we only bind options for that helper:

var self = this;
var locals = self.context();
var helpers = self._.helpers;
locals.helpers = _.transform(helpers, function (acc, fn, key) {
    var o = {};
    o.context = locals;
    o.app = self;
    o.options = self.option(key) || {};
    acc[key] = _.bind(fn, o);
});

Just sudo code above, but I think that'll work and it'll match up the helper with the options by the name of the helper.

[jonschlinkert]

great idea. doing this.options has crossed my mind after I posted, but was still thinking it would be better to have a property on template.options, e.g

template.option({
  helperOpts: {}
});

But it didn't occur to me to match up the options like that. we could still implement this.options.helperOpts later if it's proven to be needed

[doowb]

All options are passed into helpers now as this.options. Can this be closed or should the code be updated to only pass in options that match the helper name?

[akileez]

Sorry to interject but just for my understanding ...by doing the following ...

exports.somehelper = function (body, options, locals) {
  // this.options are options for this particular helper ???
  options = extend(Array.prototype.pop.call(arguments), this.options,  locals);
...
}

only affects this particular helper if I define options for it? It does not mess with locals in anyway? doesn't seem like it but I just want to confirm. I use the hell out of locals in all my helpers. any significant alternation means I need to adjust ...

[doowb]

No, the options don't mess with any locals that you're passing into the helper.

[akileez]

thanks @doowb for the confirm.

[jonschlinkert]

closing since this is possible out-of-the-box