Nat  Grady

Nat Grady

1658473800

Check If Code is Running in Electron Renderer Process

is-electron-renderer

Check if code is running in Electron renderer process.

Why?

Electron code can run in either the main process or the renderer process. This is the same as asking if the code is running in a web page with access to the DOM or not.

Use Cases:

  • Creating a single module that acts differently whether it's running in main or renderer.
  • Logging utility. One process (main) would be responsible for writing to log files, while renderers would send log data to the main. Would allow your code to have one log method.
  • Testing. Your test code may behave differently if the DOM is available.
  • Normalize console.log behavior. console.log behavior is weird in renderer, this can easily be fixed.

Install

npm i --save is-electron-renderer

Usage

You'll notice that when using console.log in Electron that in the renderer process outputs some weird log level garbage to stderr before your actual console message. You can normalize this behavior:

console-hook.js:

// clean up Electron output
function hook () {
  var isRenderer = require('is-electron-renderer')
  var pre = '(' + (isRenderer ? 'RENDERER' : 'MAIN') + ') '
  console.log = function (msg) {
    process.stdout.write(pre + msg + '\n')
  }
}

module.exports = {
  hook: hook
}

index.js:

require('./console-hook').hook()
console.log('hello')

output (main):

(MAIN) hello

output (renderer):

(RENDERER) hello

API

var isRenderer = require('is-electron-renderer')
console.log(isRenderer)
// => (BOOLEAN)

 Read more here: https://github.com/atom/electron/blob/master/docs/tutorial/quick-start.md

Author: jprichardson
Source Code: https://github.com/jprichardson/is-electron-renderer 
License: MIT

#electron #renderer 

What is GEEK

Buddha Community

Check If Code is Running in Electron Renderer Process
Nat  Grady

Nat Grady

1658473800

Check If Code is Running in Electron Renderer Process

is-electron-renderer

Check if code is running in Electron renderer process.

Why?

Electron code can run in either the main process or the renderer process. This is the same as asking if the code is running in a web page with access to the DOM or not.

Use Cases:

  • Creating a single module that acts differently whether it's running in main or renderer.
  • Logging utility. One process (main) would be responsible for writing to log files, while renderers would send log data to the main. Would allow your code to have one log method.
  • Testing. Your test code may behave differently if the DOM is available.
  • Normalize console.log behavior. console.log behavior is weird in renderer, this can easily be fixed.

Install

npm i --save is-electron-renderer

Usage

You'll notice that when using console.log in Electron that in the renderer process outputs some weird log level garbage to stderr before your actual console message. You can normalize this behavior:

console-hook.js:

// clean up Electron output
function hook () {
  var isRenderer = require('is-electron-renderer')
  var pre = '(' + (isRenderer ? 'RENDERER' : 'MAIN') + ') '
  console.log = function (msg) {
    process.stdout.write(pre + msg + '\n')
  }
}

module.exports = {
  hook: hook
}

index.js:

require('./console-hook').hook()
console.log('hello')

output (main):

(MAIN) hello

output (renderer):

(RENDERER) hello

API

var isRenderer = require('is-electron-renderer')
console.log(isRenderer)
// => (BOOLEAN)

 Read more here: https://github.com/atom/electron/blob/master/docs/tutorial/quick-start.md

Author: jprichardson
Source Code: https://github.com/jprichardson/is-electron-renderer 
License: MIT

#electron #renderer 

Tyrique  Littel

Tyrique Littel

1604008800

Static Code Analysis: What It Is? How to Use It?

Static code analysis refers to the technique of approximating the runtime behavior of a program. In other words, it is the process of predicting the output of a program without actually executing it.

Lately, however, the term “Static Code Analysis” is more commonly used to refer to one of the applications of this technique rather than the technique itself — program comprehension — understanding the program and detecting issues in it (anything from syntax errors to type mismatches, performance hogs likely bugs, security loopholes, etc.). This is the usage we’d be referring to throughout this post.

“The refinement of techniques for the prompt discovery of error serves as well as any other as a hallmark of what we mean by science.”

  • J. Robert Oppenheimer

Outline

We cover a lot of ground in this post. The aim is to build an understanding of static code analysis and to equip you with the basic theory, and the right tools so that you can write analyzers on your own.

We start our journey with laying down the essential parts of the pipeline which a compiler follows to understand what a piece of code does. We learn where to tap points in this pipeline to plug in our analyzers and extract meaningful information. In the latter half, we get our feet wet, and write four such static analyzers, completely from scratch, in Python.

Note that although the ideas here are discussed in light of Python, static code analyzers across all programming languages are carved out along similar lines. We chose Python because of the availability of an easy to use ast module, and wide adoption of the language itself.

How does it all work?

Before a computer can finally “understand” and execute a piece of code, it goes through a series of complicated transformations:

static analysis workflow

As you can see in the diagram (go ahead, zoom it!), the static analyzers feed on the output of these stages. To be able to better understand the static analysis techniques, let’s look at each of these steps in some more detail:

Scanning

The first thing that a compiler does when trying to understand a piece of code is to break it down into smaller chunks, also known as tokens. Tokens are akin to what words are in a language.

A token might consist of either a single character, like (, or literals (like integers, strings, e.g., 7Bob, etc.), or reserved keywords of that language (e.g, def in Python). Characters which do not contribute towards the semantics of a program, like trailing whitespace, comments, etc. are often discarded by the scanner.

Python provides the tokenize module in its standard library to let you play around with tokens:

Python

1

import io

2

import tokenize

3

4

code = b"color = input('Enter your favourite color: ')"

5

6

for token in tokenize.tokenize(io.BytesIO(code).readline):

7

    print(token)

Python

1

TokenInfo(type=62 (ENCODING),  string='utf-8')

2

TokenInfo(type=1  (NAME),      string='color')

3

TokenInfo(type=54 (OP),        string='=')

4

TokenInfo(type=1  (NAME),      string='input')

5

TokenInfo(type=54 (OP),        string='(')

6

TokenInfo(type=3  (STRING),    string="'Enter your favourite color: '")

7

TokenInfo(type=54 (OP),        string=')')

8

TokenInfo(type=4  (NEWLINE),   string='')

9

TokenInfo(type=0  (ENDMARKER), string='')

(Note that for the sake of readability, I’ve omitted a few columns from the result above — metadata like starting index, ending index, a copy of the line on which a token occurs, etc.)

#code quality #code review #static analysis #static code analysis #code analysis #static analysis tools #code review tips #static code analyzer #static code analysis tool #static analyzer

Beth  Cooper

Beth Cooper

1659694200

Easy Activity Tracking for Models, Similar to Github's Public Activity

PublicActivity

public_activity provides easy activity tracking for your ActiveRecord, Mongoid 3 and MongoMapper models in Rails 3 and 4.

Simply put: it can record what happens in your application and gives you the ability to present those recorded activities to users - in a similar way to how GitHub does it.

!! WARNING: README for unreleased version below. !!

You probably don't want to read the docs for this unreleased version 2.0.

For the stable 1.5.X readme see: https://github.com/chaps-io/public_activity/blob/1-5-stable/README.md

About

Here is a simple example showing what this gem is about:

Example usage

Tutorials

Screencast

Ryan Bates made a great screencast describing how to integrate Public Activity.

Tutorial

A great step-by-step guide on implementing activity feeds using public_activity by Ilya Bodrov.

Online demo

You can see an actual application using this gem here: http://public-activity-example.herokuapp.com/feed

The source code of the demo is hosted here: https://github.com/pokonski/activity_blog

Setup

Gem installation

You can install public_activity as you would any other gem:

gem install public_activity

or in your Gemfile:

gem 'public_activity'

Database setup

By default public_activity uses Active Record. If you want to use Mongoid or MongoMapper as your backend, create an initializer file in your Rails application with the corresponding code inside:

For Mongoid:

# config/initializers/public_activity.rb
PublicActivity.configure do |config|
  config.orm = :mongoid
end

For MongoMapper:

# config/initializers/public_activity.rb
PublicActivity.configure do |config|
  config.orm = :mongo_mapper
end

(ActiveRecord only) Create migration for activities and migrate the database (in your Rails project):

rails g public_activity:migration
rake db:migrate

Model configuration

Include PublicActivity::Model and add tracked to the model you want to keep track of:

For ActiveRecord:

class Article < ActiveRecord::Base
  include PublicActivity::Model
  tracked
end

For Mongoid:

class Article
  include Mongoid::Document
  include PublicActivity::Model
  tracked
end

For MongoMapper:

class Article
  include MongoMapper::Document
  include PublicActivity::Model
  tracked
end

And now, by default create/update/destroy activities are recorded in activities table. This is all you need to start recording activities for basic CRUD actions.

Optional: If you don't need #tracked but still want the comfort of #create_activity, you can include only the lightweight Common module instead of Model.

Custom activities

You can trigger custom activities by setting all your required parameters and triggering create_activity on the tracked model, like this:

@article.create_activity key: 'article.commented_on', owner: current_user

See this entry http://rubydoc.info/gems/public_activity/PublicActivity/Common:create_activity for more details.

Displaying activities

To display them you simply query the PublicActivity::Activity model:

# notifications_controller.rb
def index
  @activities = PublicActivity::Activity.all
end

And in your views:

<%= render_activities(@activities) %>

Note: render_activities is an alias for render_activity and does the same.

Layouts

You can also pass options to both activity#render and #render_activity methods, which are passed deeper to the internally used render_partial method. A useful example would be to render activities wrapped in layout, which shares common elements of an activity, like a timestamp, owner's avatar etc:

<%= render_activities(@activities, layout: :activity) %>

The activity will be wrapped with the app/views/layouts/_activity.html.erb layout, in the above example.

Important: please note that layouts for activities are also partials. Hence the _ prefix.

Locals

Sometimes, it's desirable to pass additional local variables to partials. It can be done this way:

<%= render_activity(@activity, locals: {friends: current_user.friends}) %>

Note: Before 1.4.0, one could pass variables directly to the options hash for #render_activity and access it from activity parameters. This functionality is retained in 1.4.0 and later, but the :locals method is preferred, since it prevents bugs from shadowing variables from activity parameters in the database.

Activity views

public_activity looks for views in app/views/public_activity.

For example, if you have an activity with :key set to "activity.user.changed_avatar", the gem will look for a partial in app/views/public_activity/user/_changed_avatar.html.(|erb|haml|slim|something_else).

Hint: the "activity." prefix in :key is completely optional and kept for backwards compatibility, you can skip it in new projects.

If you would like to fallback to a partial, you can utilize the fallback parameter to specify the path of a partial to use when one is missing:

<%= render_activity(@activity, fallback: 'default') %>

When used in this manner, if a partial with the specified :key cannot be located it will use the partial defined in the fallback instead. In the example above this would resolve to public_activity/_default.html.(|erb|haml|slim|something_else).

If a view file does not exist then ActionView::MisingTemplate will be raised. If you wish to fallback to the old behaviour and use an i18n based translation in this situation you can specify a :fallback parameter of text to fallback to this mechanism like such:

<%= render_activity(@activity, fallback: :text) %>

i18n

Translations are used by the #text method, to which you can pass additional options in form of a hash. #render method uses translations when view templates have not been provided. You can render pure i18n strings by passing {display: :i18n} to #render_activity or #render.

Translations should be put in your locale .yml files. To render pure strings from I18n Example structure:

activity:
  article:
    create: 'Article has been created'
    update: 'Someone has edited the article'
    destroy: 'Some user removed an article!'

This structure is valid for activities with keys "activity.article.create" or "article.create". As mentioned before, "activity." part of the key is optional.

Testing

For RSpec you can first disable public_activity and add require helper methods in the rails_helper.rb with:

#rails_helper.rb
require 'public_activity/testing'

PublicActivity.enabled = false

In your specs you can then blockwise decide whether to turn public_activity on or off.

# file_spec.rb
PublicActivity.with_tracking do
  # your test code goes here
end

PublicActivity.without_tracking do
  # your test code goes here
end

Documentation

For more documentation go here

Common examples

Set the Activity's owner to current_user by default

You can set up a default value for :owner by doing this:

  1. Include PublicActivity::StoreController in your ApplicationController like this:
class ApplicationController < ActionController::Base
  include PublicActivity::StoreController
end
  1. Use Proc in :owner attribute for tracked class method in your desired model. For example:
class Article < ActiveRecord::Base
  tracked owner: Proc.new{ |controller, model| controller.current_user }
end

Note: current_user applies to Devise, if you are using a different authentication gem or your own code, change the current_user to a method you use.

Disable tracking for a class or globally

If you need to disable tracking temporarily, for example in tests or db/seeds.rb then you can use PublicActivity.enabled= attribute like below:

# Disable p_a globally
PublicActivity.enabled = false

# Perform some operations that would normally be tracked by p_a:
Article.create(title: 'New article')

# Switch it back on
PublicActivity.enabled = true

You can also disable public_activity for a specific class:

# Disable p_a for Article class
Article.public_activity_off

# p_a will not do anything here:
@article = Article.create(title: 'New article')

# But will be enabled for other classes:
# (creation of the comment will be recorded if you are tracking the Comment class)
@article.comments.create(body: 'some comment!')

# Enable it again for Article:
Article.public_activity_on

Create custom activities

Besides standard, automatic activities created on CRUD actions on your model (deactivatable), you can post your own activities that can be triggered without modifying the tracked model. There are a few ways to do this, as PublicActivity gives three tiers of options to be set.

Instant options

Because every activity needs a key (otherwise: NoKeyProvided is raised), the shortest and minimal way to post an activity is:

@user.create_activity :mood_changed
# the key of the action will be user.mood_changed
@user.create_activity action: :mood_changed # this is exactly the same as above

Besides assigning your key (which is obvious from the code), it will take global options from User class (given in #tracked method during class definition) and overwrite them with instance options (set on @user by #activity method). You can read more about options and how PublicActivity inherits them for you here.

Note the action parameter builds the key like this: "#{model_name}.#{action}". You can read further on options for #create_activity here.

To provide more options, you can do:

@user.create_activity action: 'poke', parameters: {reason: 'bored'}, recipient: @friend, owner: current_user

In this example, we have provided all the things we could for a standard Activity.

Use custom fields on Activity

Besides the few fields that every Activity has (key, owner, recipient, trackable, parameters), you can also set custom fields. This could be very beneficial, as parameters are a serialized hash, which cannot be queried easily from the database. That being said, use custom fields when you know that you will set them very often and search by them (don't forget database indexes :) ).

Set owner and recipient based on associations

class Comment < ActiveRecord::Base
  include PublicActivity::Model
  tracked owner: :commenter, recipient: :commentee

  belongs_to :commenter, :class_name => "User"
  belongs_to :commentee, :class_name => "User"
end

Resolve parameters from a Symbol or Proc

class Post < ActiveRecord::Base
  include PublicActivity::Model
  tracked only: [:update], parameters: :tracked_values
  
  def tracked_values
   {}.tap do |hash|
     hash[:tags] = tags if tags_changed?
   end
  end
end

Setup

Skip this step if you are using ActiveRecord in Rails 4 or Mongoid

The first step is similar in every ORM available (except mongoid):

PublicActivity::Activity.class_eval do
  attr_accessible :custom_field
end

place this code under config/initializers/public_activity.rb, you have to create it first.

To be able to assign to that field, we need to move it to the mass assignment sanitizer's whitelist.

Migration

If you're using ActiveRecord, you will also need to provide a migration to add the actual field to the Activity. Taken from our tests:

class AddCustomFieldToActivities < ActiveRecord::Migration
  def change
    change_table :activities do |t|
      t.string :custom_field
    end
  end
end

Assigning custom fields

Assigning is done by the same methods that you use for normal parameters: #tracked, #create_activity. You can just pass the name of your custom variable and assign its value. Even better, you can pass it to #tracked to tell us how to harvest your data for custom fields so we can do that for you.

class Article < ActiveRecord::Base
  include PublicActivity::Model
  tracked custom_field: proc {|controller, model| controller.some_helper }
end

Help

If you need help with using public_activity please visit our discussion group and ask a question there:

https://groups.google.com/forum/?fromgroups#!forum/public-activity

Please do not ask general questions in the Github Issues.


Author: public-activity
Source code: https://github.com/public-activity/public_activity
License: MIT license

#ruby  #ruby-on-rails 

Samanta  Moore

Samanta Moore

1621137960

Guidelines for Java Code Reviews

Get a jump-start on your next code review session with this list.

Having another pair of eyes scan your code is always useful and helps you spot mistakes before you break production. You need not be an expert to review someone’s code. Some experience with the programming language and a review checklist should help you get started. We’ve put together a list of things you should keep in mind when you’re reviewing Java code. Read on!

1. Follow Java Code Conventions

2. Replace Imperative Code With Lambdas and Streams

3. Beware of the NullPointerException

4. Directly Assigning References From Client Code to a Field

5. Handle Exceptions With Care

#java #code quality #java tutorial #code analysis #code reviews #code review tips #code analysis tools #java tutorial for beginners #java code review

Houston  Sipes

Houston Sipes

1604088000

How to Find the Stinky Parts of Your Code (Part II)

There are more code smells. Let’s keep changing the aromas. We see several symptoms and situations that make us doubt the quality of our development. Let’s look at some possible solutions.

Most of these smells are just hints of something that might be wrong. They are not rigid rules.

This is part II. Part I can be found here.

Code Smell 06 - Too Clever Programmer

The code is difficult to read, there are tricky with names without semantics. Sometimes using language’s accidental complexity.

_Image Source: NeONBRAND on _Unsplash

Problems

  • Readability
  • Maintainability
  • Code Quality
  • Premature Optimization

Solutions

  1. Refactor the code
  2. Use better names

Examples

  • Optimized loops

Exceptions

  • Optimized code for low-level operations.

Sample Code

Wrong

function primeFactors(n){
	  var f = [],  i = 0, d = 2;  

	  for (i = 0; n >= 2; ) {
	     if(n % d == 0){
	       f[i++]=(d); 
	       n /= d;
	    }
	    else{
	      d++;
	    }     
	  }
	  return f;
	}

Right

function primeFactors(numberToFactor){
	  var factors = [], 
	      divisor = 2,
	      remainder = numberToFactor;

	  while(remainder>=2){
	    if(remainder % divisor === 0){
	       factors.push(divisor); 
	       remainder = remainder/ divisor;
	    }
	    else{
	      divisor++;
	    }     
	  }
	  return factors;
	}

Detection

Automatic detection is possible in some languages. Watch some warnings related to complexity, bad names, post increment variables, etc.

#pixel-face #code-smells #clean-code #stinky-code-parts #refactor-legacy-code #refactoring #stinky-code #common-code-smells