Code For America 2015 Interview question. Take the provided CSV, use your preferred language to parse it and display the data. Requested information was 1) the number of violations in each category, 2) the earliest violation date for each category and 3) the latest violation date for each category. jQuery is listed as a dependency but only for p…

Violations-2012.csv

ViolationsParse.js

(function(window, document, $, undefined){

  var VIOLATION_CATEGORIES = []; // To be constructed while parsing data

  // Simple Violation 'Model'
  function Violation(v_id, inspection_id, v_category, v_date, v_date_closed, v_type){
    this.v_id = v_id;
    this.inspection_id = inspection_id;
    this.v_category = v_category;
    this.v_date = new Date(v_date);
    this.v_date_closed = new Date(v_date_closed);
    this.v_type = v_type;

    return this;
  }

  // Returns an object with violation categories as keys.  Each key points to a new object with the following keys:
  // 'earliestViolation' => (Date) 
  // 'latestViolation' => (Date)
  // 'violations' => (Array) All violations contained under that category
  function csvParse(inputData) {

    var parseResult = {};

    var csvLineByLine = inputData.split('\n'); // Split lines of the file by the whitespace line delimiter

    var csvHeaders = csvLineByLine.shift(); // Remove the first element (line of the CSV) since it contains the header information


    for (var i = csvLineByLine.length - 1; i >= 0; i--) {
      
      var lineToArray = csvLineByLine[i].split(','); // COMMA separated value list

      var violation = new Violation(lineToArray[0], lineToArray[1], lineToArray[2], lineToArray[3], lineToArray[4], lineToArray[5]), // Create a Violation model instance
          vCategory = violation.v_category; // Make shortcut to obj prop

      if(!parseResult.hasOwnProperty(vCategory)){ // Create the category in the parseResult and initialize it with the date of the violation for earliest and latest, and the array of violations in that category

        VIOLATION_CATEGORIES.push(vCategory);

        parseResult[vCategory] = {
          earliestViolation: violation.v_date,
          latestViolation: violation.v_date,
          violations: [violation]
        };
      }
      else {
        
        var parseResultCat = parseResult[vCategory];
        var violationDate = violation.v_date;

        parseResultCat.violations.push(violation);

        if(violationDate < parseResultCat.earliestViolation){ // Overwrite the earliest violation date if this violation is earlier
          parseResult[vCategory].earliestViolation = violationDate;
        }
        if(violationDate > parseResultCat.latestViolation){ // Overwrite the earliest violation date if this violation is later
          parseResultCat.latestViolation = violationDate;
        }

      }

    }

    return parseResult;
  }

  function csvLoaded(csv){
    console.log(csv);
    var data = csvParse(csv);

    console.log("2012 City Violations (Organized by violation type)");
    console.log("==================================================");
    console.log("");


    // List the info in the console
    for (var i = VIOLATION_CATEGORIES.length - 1; i >= 0; i--) {
      var cat = VIOLATION_CATEGORIES[i];
      var categoryData = data[cat];

      console.log('=='+ cat +'==');

      console.log('Total number: ' + categoryData.violations.length);

      console.log('Earliest violation date: ' + categoryData.earliestViolation.toLocaleDateString());

      console.log('Latest violation date: ' + categoryData.latestViolation.toLocaleDateString());

      console.log('');

    }
    
  }

  $.ajax({
    url: 'Violations-2012.csv',
  })
  .done( csvLoaded );

})(window, document, jQuery);

ViolationsParseOutput

2012 City Violations (Organized by violation type)
=================================================

==Vegetation==
Total number: 67
Earliest violation date: 2/1/2012
Latest violation date: 12/5/2012

==Chemical Hazards==
Total number: 17
Earliest violation date: 2/8/2012
Latest violation date: 12/6/2012

==Biohazards==
Total number: 7
Earliest violation date: 4/13/2012
Latest violation date: 12/18/2012

==Air Pollutants and Odors==
Total number: 2
Earliest violation date: 12/5/2012
Latest violation date: 12/19/2012

==Garbage and Refuse==
Total number: 126
Earliest violation date: 1/3/2012
Latest violation date: 12/21/2012

==Unsanitary Conditions==
Total number: 83
Earliest violation date: 1/3/2012
Latest violation date: 12/19/2012

==Retail Food==
Total number: 1
Earliest violation date: 12/20/2012
Latest violation date: 12/20/2012

==Building Conditions==
Total number: 62
Earliest violation date: 1/12/2012
Latest violation date: 12/26/2012

==Animals and Pests==
Total number: 180
Earliest violation date: 1/3/2012
Latest violation date: 12/28/2012