activerecord GROUPed BY in batches

We are all familiar with activerecord .find_in_batches. The main idea behind it is not allowing to load thousands of ActiveRecord objects in memory which would cause tear down the server. I looked at this method and I looked at `.group` which applies GROUP BY clause. Just for fun, I thought what if I receive these “grouped_by” data in batches, something like

 scope.grouped_by_in_batches(group_by_column) do |batch, value|
  batch is an array same as we get in case of `find_in_batches`
  value is the grouped value of the column
 end

Hence I worked on this idea, made a pull request which obliviously did not work, as this was not a common use case, thats all fine. I agree to it. Even I never got to use it till date. However in attempt to do so, I really enjoyed writing test cases for it, getting interacted with a couple of ruby/rails expertise. Feeling happy about it.

rspec STDOUT

I happened to write some rspec for one ruby program which was accepting some input text in some form, and then it was expected to print the output to the console, or perhaps I did not want to separate the logic of printing. Anyways, that made me expect rspec should check the console output of my program, and after some googling(thanks to many rubyist) I got to work the following

Wow, I liked it.

And the spec_helper made it for me

Highlight changes being made on ActiveRecord object inside email

I simply needed one helper method which would help me highlight changes being made on any ActiveRecord object inside email. Below is one example of that I have come up with and would like to extend it in my future projects too.

It gave me some insights into ActiveRecord::Base#previous_changes and ActiveRecord::Base#reflections. Nice to learn such ActiveRecord features.

samg/diffy also helped me out decorating text changes

Screenshot from 2014-01-16 13:50:15

Adding to my MailerHelper

a quick javascript lightbox

I had to develop some feature which required some javascript lightbox,
I really not needed a fancy one, but a small or medium one
it was for some small confirmation and in addition a couple of inputs on confirmation
so you can imagine a small html form being poped up
I had to add one then, and I guessed tomorrow there might be couple of more coming

I found very nice options when googled
but I thought of implementing one of my own just for fun, and I got this a quick one

admin.lightbox.show(
  html: "my html goes here"
  title: "my title"
).done(->
  alert "Am done"

hi there

And it really took a very less time to build this one as follows

The most interesting part here is to be able to define callbacks like done and cancel.

And I welcome all suggestions :)

activeadmin cool tweaks

tweak 1: Make some column quick-editable on the index list page

1

Ok… so I want to be quickly able to edit few names, here on the same list page, something like below

2

Thats simply great!

Now it makes me quickly update any name there itself on the list page, <enter> will make it, <escape> will ignore it, and <tab> will move to the next one. awesome.

And to make it work I just need to have one line of code change

All I need to say is `editable_test_column`, and its done.

And here how it works, you will need to define a couple of things

You need to define editable_text_column, this you could place inside app/admin/lib/

Then you will need to add some javascript …

and some css stuff

Thats it.

Next, I would love to quickly alter article type say having a dropdown there to save my time

tweak 2: quick editable dropdowns on list page

6

Ohh, now this is again great!   … no? It actually updates the article type on value change. nice.

Let see the code behind

and to define `column_select`

CustomHelper is one of my helper modules that really helps me render dropdown the way I need, and provides me some nice options, one may choose to use the default rails select helpers

Then you need some javascript

done.

I do have worked out several more tweaks like toggle button for boolean column, show/hide columns on the list page, auto-populate/suggest feature for string filters, one can make use ActiveAdmin icons too, then for one of my requirements I have set up the whole custom header and a dozens of custom pages. I would easily say that ActiveAdmin is just simple and awesome, one can really customize it to the extreme, the code structure will allow you to imagine and implement a number of custom scenarios.

google “chef-solo rails deploy git submodule checkout branch sha”

Working with chef resource deploy, faced several issues with Git provider, for examples

- enable_submodule does not work properly
– it does not get the latest code from submodules
– it does not allow you to choose specific branch and sha of any submodule
– in fact for main repo it does not allow you to switch to any specific branch and sha
– for some reason it says branch=version, who knows why ….

I tried correcting all above, and below is one of my examples, its working for me