Extended renderEach with data objects support

[ggodet-bar]

Hello Aaron,

First of all, thanks for the great work on Sammy, this is really a cool project to work with. Back to my pull request: I extended renderEach so that it may handle data objects when interpolating with the template.

Cheers,

Guillaume

[quirkey]

I don't know if I completely understand the use case for this. Can you explain or give a better example of when you'd need two separate interpolation objects?

[ggodet-bar]

Using two interpolation objects allows injecting data that is specific to the array element and generic data that applies to all rendered items.

Case study:
I'm working on yet another task management app. The task template requires a task object (obviously), but also generic data for filling dropdowns, such as the project id, available task statuses or available task priorities (which should be the same for all displayed tasks). Using the new renderEach method, I can thus call:
render_ctx.renderEach('templates/_task.html.erb', 'task', tasks_page, {project_id: project.id(), statuses: task_statuses, priorities: task_priorities}, task_callback) ;