Pass data to javascript

[Linus Pettersson]

Hi!

I'm creating a bar graph using Morris.js. What I'm showing in the graph is dates on the X-axis and the number of times an event has occurred on that date on the Y-axis.

So, I followed Ryan Bates episode on Morris.js: http://railscasts.com/episodes/223-charts-graphs-revised (It's a PRO episode so I will explain more).

I created a class method in my model that fetches all records, groups by date and count the occurrences. This method is called by a helper method from my view. The helper method loops over the date range and checks the number of occurrences for that date and adds it to a hash (dates that doesn't exist in the database is set to 0).

This hash is then simply added to my view as a data attribute (data-events="{....}") which I'm fetching using JS and adding to the graph.

The questions I have are:

- Is this a good approach?

- Would it be better to add another action to my controller and have that return the data needed as JSON and call just this using javascript?

What are the benefits/drawbacks of the different approaches?

[Linus Pettersson]

Another option would be to fetch the raw JSON data using javascript from .../events.json and then do the grouping and whatever client-side and pass to the graph... Maybe too inefficient?

// Linus

[Robert Walker]

Linus Pettersson wrote in post #1093722:

> I created a class method in my model that fetches all records, groups by
> date and count the occurrences. This method is called by a helper method
> from my view. The helper method loops over the date range and checks the
> number of occurrences for that date and adds it to a hash (dates that
> doesn't exist in the database is set to 0).
> This hash is then simply added to my view as a data attribute
> (data-events="{....}") which I'm fetching using JS and adding to the
> graph.
>
> The questions I have are:
> - Is this a good approach?
> - Would it be better to add another action to my controller and have
> that
> return the data needed as JSON and call just this using javascript?
>
> What are the benefits/drawbacks of the different approaches?

Generally speaking try to avoid pre-mature optimization.

1. Go with the simplest solution that could possibly work.

2. Gather some metrics.

3. Try a different approach that you think might improve performance.

4. Goto step 2 until step 3 is exhausted.

--
Posted via http://www.ruby-forum.com/.

[Robert Walker]

Robert Walker wrote in post #1094237:

>> What are the benefits/drawbacks of the different approaches?
>
> Generally speaking try to avoid pre-mature optimization.
>
> 1. Go with the simplest solution that could possibly work.
>
> 2. Gather some metrics.
>
> 3. Try a different approach that you think might improve performance.
>
> 4. Goto step 2 until step 3 is exhausted.

Oh! Forgot to mention that Ryan Bates also created an episode that might
be useful for you.

http://railscasts.com/episodes/324-passing-data-to-javascript