Pass data to javascript

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?

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

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.

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