Now that we've moved the logic to generate the events data to a model,
and we've got access to the model in the component rendering the chart,
we can render the data inside the chart instead of doing an extra AJAX
request to get the same data.
Originally, this was problaby done this way so the page wouldn't take
several seconds to load while preparing the data for the chart when
there are thousands of dates being displayed. With an AJAX call, the
page would load as fast as usual, and then the chart would render after
a few seconds. However, we can have an even better performance
improvement in this scenario if we use a Set instead of an Array. The
method `Array#include?`, which we were calling for every date in the
data, is much slower that `Set#merge`. So now both the page and the
chart load as fast as expected.
We could also use something like:
```
def add
(...)
shared_keys.push(*collection.keys)
end
def build
(...)
shared_keys.uniq.each do |k|
(...)
end
def shared_keys
@shared_keys ||= []
end
```
Or other approaches to avoid using `Array#include?`. The performance
would be similar to the one we get when using `Set`. We're using a `Set`
because it makes more obvious that `shared_keys` is supposed to contain
unique elements.
We've had some tests failing in the past due to these AJAX requests
being triggered automatically during the tests and no expectations
checking the requests have finished, so now we're reducing the amount of
flaky tests.
We were always displaying the event names in English.
Note we're changing the `user_supported_budgets` key because it didn't
make much sense; the investments are supported, and not the budgets.
We're also adding "created" to most of the event names in order to make
the texts more explicit, since not all the events refer to created data.
Note we're delegating the `t` method because i18n-tasks doesn't detect
code like `ApplicationController.helpers.t` and so reports we aren't
using the `admin.stats.graph` translations.
Using <h3> headings for the links had two disadvantages.
First, it was the wrong heading level to use, since there was no <h2>
tag before it.
Second, headings are supposed to be followed by content associated to
that heading; here, we had no content following the headings.
So we're using a list of links and giving it a heading. We're adding
styles so the page still looks like it used to, although these styles
are certainly asking for improvements.
The JavaScript required to display the chart wasn't loaded on the admin
stats page.
We're not adding a test because we're going to move the budgets graph to
a different page on the pull request containing this commit.
Note we're changing the "Go back" link, since using a turbolinks refresh
broke this link when using the Chromium browser. Besides, there was an
inconsistency where some of the "Go back" links in admin stats pointed
to the admin stats page but other links pointed to `:back`.
This is consistent with the component for balloting stats. We're about
to change both components, and the changes are easier to follow if
they're similar.
We're also using consistent names in methods.
To get the heading where a user voted, we were relying on the
`balloted_heading_id` field.
Our guess is this was done so the total number of users is the same as
the sum of users who voted on a heading. That is, if 2000 people voted
just on the "All city" heading, 1000 voted just on the "North district"
heading, and 500 people voted on both, instead of showing "3500 people
voted in total, 2500 voted in all city, 1500 voted in north district",
we show something like "3500 people voted in total, 2250 voted in all
city, and 1250 voted in north district".
However, this approach has some disadvantages.
The first disadvantage is, the stats aren't correct. In the case above,
2500 voted on the "All city heading", so the statistics for this heading
don't show reality.
The second one is we weren't considering the last heading where users
voted inside the budget being displayed, but the last heading where
users voted, period. That means that, if all the people above voted on a
later budget, the stats for the budget above would become "3500 people
voted in total, 0 voted in all city, and 0 voted in north district".
That also means we were including headings from previous budgets in the
statistics for more recent budgets when people hadn't voted on the
recent ones.
So we're removing the `balloted_heading_id` since its data is lost once
people vote on a new budget. And, in order to show the right stats and
simplify the code, we're no longer trying to add votes just to one
heading when users vote on several headings.
Co-Authored-By: Julian Nicolas Herrero <microweb10@gmail.com>
We're also moving the tests, but we're keeping one system test in order
to test the controller and the navigation to get to this page.
Note we're slightly changing the order of the methods in the component;
the order of the instance variables was `user_`, `vote_`, `vote_`,
`user_`, which was hard to follow.
