Underscore.js(_) : Difference between _.where() and _.findwhere()

Underscore.js is a utility-belt JavaScript library for JavaScript that provides a lot of the functional programming. You can easily manipulate data collection to sort and display it.

_.where ():  

where() function always return the object or list of object contains the specific property from collection of object.

Syntax:

_.where(list, filters);

·         list – collection of item

·         filters – parameters which contains conditions

Here is a collection of objects:

var goal = [

    {

        "category": "education",

        "title": "Charlie University",

        "description": "Lorem ipsum dolor sit amet",

        "date": "01/03/2020",

        "value": 50000,

        "achievability": 2,

        "experimental_achievability": 3,

        "suggested": false,

        "accounts": [],

        "articles": [],

        "related_goals": [],

        "id": "1"

    },

    {

        "category": "education",

        "title": "Charlie University",

        "description": "Lorem ipsum dolor sit amet",

        "date": "01/03/2020",

        "value": 50000,

        "achievability": 3,

        "experimental_achievability": 3,

        "suggested": false,

        "accounts": [],

        "articles": [],

        "related_goals": [],

        "id": "2"

    },

    {

        "category": "education",

        "title": "Charlie University",

        "description": "Lorem ipsum dolor sit amet",

        "date": "01/03/2020",

        "value": 50000,

        "achievability": 2,

        "experimental_achievability": 3,

        "suggested": false,

        "accounts": [],

        "articles": [],

        "related_goals": [],

        "id": "3"

    },

    {

        "category": "education",

        "title": "Charlie University",

        "description": "Lorem ipsum dolor sit amet",

        "date": "01/03/2020",

        "value": 50000,

        "achievability": 3,

        "experimental_achievability": 3,

        "suggested": false,

        "accounts": [],

        "articles": [],

        "related_goals": [],

        "id": "4"

    }

]

var filteredGoal = _.where(goal, { achievability: "3" });

filteredGoal is having all matching objects, which have achievability property value 3.

[

    {

        "category": "education",

        "title": "Charlie University",

        "description": "Lorem ipsum dolor sit amet",

        "date": "01/03/2020",

        "value": 50000,

        "achievability": 3,

        "experimental_achievability": 3,

        "suggested": false,

        "accounts": [],

        "articles": [],

        "related_goals": [],

        "id": "2"

    },

    {

        "category": "education",

        "title": "Charlie University",

        "description": "Lorem ipsum dolor sit amet",

        "date": "01/03/2020",

        "value": 50000,

        "achievability": 3,

        "experimental_achievability": 3,

        "suggested": false,

        "accounts": [],

        "articles": [],

        "related_goals": [],

        "id": "4"

    }

]

_.findwhere() : findwhere () function always returns the first matched object in collection.

Syntax:

_. findwhere (list, filters);

·         list – collection of item

·         filters – parameters which contains conditions

var filteredGoal = _.findwhere(goal, { achievability: "3" });

filteredGoal is having only first matching record of goal collections

    {

        "category": "education",

        "title": "Charlie University",

        "description": "Lorem ipsum dolor sit amet",

        "date": "01/03/2020",

        "value": 50000,

        "achievability": 3,

        "experimental_achievability": 3,

        "suggested": false,

        "accounts": [],

        "articles": [],

        "related_goals": [],

        "id": "2"

    }

Additional link: 

http://underscorejs.org/#where

Installation and Configuration of Karma [Jasmine Unit test runner]

Karma Installation

There are few steps to install Karma ( Jasmine Unit Test Runner )

1.       Download and Install Node.js

2.       Download and Install Python 2.7

3.       Set Python Environment Variable

[npm Config set python python 2.7]

4.       Run command to install Karma

 [npm install –g Karma]  

5.       Configure Karma js file [ Karma excute unit tests according to a karma.config.js configuration file ] you can generate automatically  karma.config.js  file by running following command

[karma init]

6.       Start Karma

Karma start karma.config.js 

Sample js file of karma.config.js

module.exports = function(config) {

    config.set({

        // base path that will be used to resolve all patterns (eg. files, exclude)

        basePath: '',

        // frameworks to use

        // available frameworks: https://npmjs.org/browse/keyword/karma-adapter

        frameworks: ['jasmine'],

        // list of files / patterns to load in the browser

        files: [

           'Scripts/jasmine/jasmine.js',

           'Scripts/angular.js',

           'Scripts/angular-mocks.js',

           'Scripts/angular-route.min.js',

           'Scripts/angular-ui-router.min.js',

           'Scripts/angular-*.js',

           'Scripts/ui*.js',

           'app/app.js', // do not change app.js position

           'app/Area/controllers/summaryController.js',

           'Scripts/Test/*Spec.js' // Jasmine Test

           ],

        // list of files to exclude

        exclude: [],

        // preprocess matching files before serving them to the browser

        // available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor

        preprocessors: {

   

        },

        // test results reporter to use

        // possible values: 'dots', 'progress'

        // available reporters: https://npmjs.org/browse/keyword/karma-reporter

        reporters: ['progress'],

        //reporters: ['spec'],

        //specReporter: {

        //    maxLogLines: 5,         // limit number of lines logged per test

        //    suppressErrorSummary: false,  // do not print error summary

        //    suppressFailed: false,  // do not print information about failed tests

        //    suppressPassed: false,  // do not print information about passed tests

        //    suppressSkipped: true  // do not print information about skipped tests

        //},

        plugins: ['karma-ie-launcher', 'karma-chrome-launcher', 'karma-jasmine'],

        // web server port

        port: 9876,

        // enable / disable colors in the output (reporters and logs)

        colors: true,

        // level of logging

        // possible values: config.LOG_DISABLE || config.LOG_ERROR || config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG

        logLevel: config.LOG_INFO,

        // enable / disable watching file and executing tests whenever any file changes

        autoWatch: true,

        // start these browsers

        // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher

        browsers: ['IE','Chrome'],

        // Continuous Integration mode

        // if true, Karma captures browsers, runs the tests and exits

        singleRun: false,

        // Concurrency level

        // how many browser should be started simultanous

        concurrency: Infinity

    });

}

Additional Source Links :
https://www.jetbrains.com/pycharm/help/running-unit-tests-on-karma.html
http://www.methodsandtools.com/tools/karma.php

Angularjs : foreach loop

angular.forEach() invokes the iterator function once for each item in obj collection, which can be either an object or array.

Syntax of ForEach loop in AngularJS:

angular.forEach($scope.data, function(value, key){});

Here are few example of angular.forEach() function:

1. Object Properties iteration:

   angular.forEach() function can be used to iterate of each property of object.

var values = {name: 'misko', gender: 'male'};

angular.forEach(values, function(value, key)

 {

    console.log(key + ': ' + value);

});

2. Object Collection Iteration:

angular.forEach() function can be used to iterate of each item of collection.

var values = [

  { "Name" : "Thomas", "Password" : "thomasTheKing" },

  { "Name" : "Linda", "Password" : "lindatheQueen" }

]

angular.forEach(values, function(value, key)

 {

  console.log ('Index:' + value.Nam);

  console.log ('Name: ' + value.Name);

  console.log ('Password: ' + value.Password);

});

Here key will work as Index of object in collection

Other blogs related to AngularJs :

AngularJs :$broadcast () , $on() and $emit()

AngularJs :scope.$watch, $watchgroup and $watchCollection

Angularjs : Model or Popup window by ngDialog API