cctiger36/model_observer

# ModelObserver

A rails plugin to count the model object creations between each request, and help to find out the duplication.

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## Installation

Add to your Gemfile

    group :development do
      gem 'model_observer'
    end

and bundle

    bundle

## Configuration

Initialize ModelObserver at `config/environments/development.rb` with the following code:

    config.after_initialize do
      ModelObserver.summary = true
      ModelObserver.instantiation_log = true
    end

## Summary Log

The summary of each request will be appended to the end like this:

    ===== Model Observer Start =====
    Author: 1 sum(10.6ms) avg(10.6ms)
    Book: 27 sum(25.7ms) avg(1.0ms)
      id(319): 3
      id(377): 3
      id(487): 3
      id(489): 3
      id(493): 3
      id(496): 3
      id(499): 3
      id(507): 3
      id(536): 3
    ===== Model Observer End =======

`id(319): 3` means the models with same class(Book) and same id(319) have been instantiated three times.

## Instantiation Log

The duration include query and instantiate models will be logged after each sql log like this:

    Author Load (0.5ms)  SELECT `authors`.* FROM `authors` WHERE `authors`.`id` = 1 LIMIT 1
    Author Instantiate (1.5ms)  SELECT `authors`.* FROM `authors` WHERE `authors`.`id` = 1 LIMIT 1

1.5ms == 0.5ms(DB query) + 1.0ms(model instantiation)