Add support for switching between widgets

[juhamust]

While switching between dashboards is nice, sometimes one wants to switch only certain widgets (while keeping the others). Thus, Mozaik should support defining multiple widgets per region.

Ideally it would be as easy as:

{
  type: ['github.user_badge', 'heroku.app_info'],
  user: 'plouc',
  app: 'mozaik',
  columns: 1, rows: 1,
  x: 0, y: 0
}

As for the widget params, both should be defined. Naturally this can be challenging with conflicting names, but it could use same array approach:

{
  type: ['weather.weather', 'weather.weather'],
  city: ['Tokyo', 'London'],
  country: ['JP', 'EN'],
  lang: 'en',
  limit: 2,
  columns: 1, rows: 1,
  x: 0, y: 1
}

I've implemented similar feature in Dashing, but I'm not yet that familiar with Flux and/or Mozaik so that I could create a PR at this point.

[plouc]

I've thought of a similar feature, (with a nice flipping effect, it could be nice), but while the second approach is feasible, the first one isn't because of the different requirements for each widgets, another option:

{
  type: 'widget.switcher',
  switchTime: 2000,
  widgets: [
    {
      type: 'weather.weather',
      //…
    },
    {
      type: 'time.clock',
      //…
    }
  ]
}

[juhamust]

Yes, a special widget type could be an option, too :) With my first example I thought that: "all the parameters are passed to both widgets, it does not matter whether they needed them or not".

But additional challenge with my proposal comes if parameter value happens to be an array. Thus, I prefer your proposal.

[juhamust]

With multiple widgets, this feature comes more and more wanted. Thus, here is my initial version for it: https://github.com/juhamust/mozaik-ext-switcher

However, it has some problem with data loading, as sometimes (most of the time) the data is not loaded properly. Care to share some consultancy, @plouc, what might be the issue ?

[juhamust]

Never mind, I figured out by myself: juhamust/mozaik-ext-switch@81e3a64#diff-3654cc213698058980abcf63f19994a0R40

[juhamust]

Described behavior can be achieved with mozaik-ext-switch