Add filters and paging to the workshop materials admin list

[aoby]

Also consolidated paging logic (now shared between teacher applications and workshop material orders) into a common Pd::PageHelper

Task

[mehalshah]

Optional suggestion for making the factory a singleton.

Does the Helper module get exercised as part of a test anywhere?

[mehalshah]

You could rewrite this as
"btn btn-default#{(disabled && ' disabled').presence}" if you don't like the ternary

[mehalshah]

Not sure if this is standard practice, but should we also have a param helper method here to filter out params other than email / filter and such?

[aoby]

This method is for Strong Parameters since these are being passed into the model in Create. Without specifying them explicitly Rails won't allow them in. This method is called by CanCan's load_and_authorize_resource in the create action and then used to populate the model.

We don't need this for params we reference explicitly in the controller that aren't passed to a model, and I'm not sure what it would add.

[mehalshah]

Optional - you could make the Factory a singleton, and pass in the base params when creating the buttons. Save you the trouble of making a new factory each time. This is a little Java Spring-y - IIRC factories are typically singletons there

[aoby]

The only reason I created the factory was to only need to specify base_params once. If we prefer to supply that for each button, then they can just be private methods in the helper.

Now that I look at it, that's probably simpler. I'll remove the factory and:

button_factory.new_page_button('<<', page: 1, disabled: collection.first_page?)

will become

new_page_button('<<', base_params.merge(page: 1), disabled: collection.first_page?)