Na weekendzie zostalem poproszony o napisanie prostego API w ramach testu programistycznego. Zadanie polegalo na polaczeniu dwoch plików JSON odpowiednim polem i posortowanie samochodow i modeli w zaleznosci od wybranych filtrow. Front-end do uzywania API byl za punkty bonusowe.
Jesli ktos zechcialby rzucic okiem i pomóc co moznaby poprawic w kodzie (test oblalem), nie dostalem konkretnego feedbacku a zapewne nie zdaje sobie sprawy z wielu bledow i "zlych praktyk".
(function() {
document.addEventListener("DOMContentLoaded", function() {
var cars = [
{
"id": "00000001",
"modelId": "ac5c3b18-6804-4e34-ac19-cf3d693f5cdf",
"mileage": 25000,
"registration": "PS128DE",
"transmission": "Manual",
"owners": 1,
"description": "<title>Car advert</title><h1>Car ad title</h1><p>Lorem ipsum dolor</p>",
"price": 13250,
"photos": [
...
]
},
{
"id": "00000002",
"modelId": "7ee87de1-a30f-4666-9741-726c9facbba7",
"mileage": 95000,
"registration": "LS05DTR",
"transmission": "Manual",
"owners": 2,
"description": "<title>Car advert</title><h1>Car ad title</h1><p>Lorem ipsum dolor</p>",
"price": 6000,
"photos": [
...
]
},
{
"id": "00000003",
"modelId": "5905c84b-4a70-47c9-be56-e814553b3015",
"mileage": 12000,
"registration": "LD58UBQ",
"transmission": "Manual",
"owners": 1,
"description": "<title>Car advert</title><h1>Car ad title</h1><p>Lorem ipsum dolor</p>",
"price": 18000,
"photos": [
...
]
},
{
"id": "00000004",
"modelId": "5905c84b-4a70-47c9-be56-e814553b3015",
"mileage": 45000,
"registration": "LD58UBQ",
"transmission": "Automatic",
"owners": 2,
"description": "<title>Car advert</title><h1>Car ad title</h1><p>Lorem ipsum dolor</p>",
"price": 12000,
"photos": [
...
]
}
];
var models = [
{
"modelId": "ac5c3b18-6804-4e34-ac19-cf3d693f5cdf",
"co2Emmissions": 124,
"mpg": "54.3",
"enginePower": 69,
"engineSize": 1229,
"fuelType": "Petrol"
},
{
"modelId": "7ee87de1-a30f-4666-9741-726c9facbba7",
"co2Emmissions": 230,
"mpg": "54.3",
"enginePower": 185,
"engineSize": 2259,
"fuelType": "Petrol"
},
{
"modelId": "5905c84b-4a70-47c9-be56-e814553b3015",
"co2Emmissions": 165,
"mpg": "54.3",
"enginePower": 130,
"engineSize": 1798,
"fuelType": "Diesel"
}
];
var getData = new QueryData();
var filterSet = [];
var result = [];
var resultMsg = document.getElementById("resultMsg");
//merging two json objects before use
function mergeJSON(dest, source, byField) {
for(var j=0;j<cars.length;j++) {
var tmp = cars[j][byField];
for(var i=0;i<models.length;i++) {
if(tmp == models[i][byField]) {
for(prop in models[i]) {
if(cars[j].hasOwnProperty(prop)) {}
else {
cars[j][prop] = models[i][prop];
}
}
}
}
}
}
//printing out cars object
function printCars(cars) {
resultMsg.innerHTML = "";
if(result.length>0) {
for(var j=0;j<cars.length;j++) {
for(prop in cars[j]) {
resultMsg.innerHTML += prop + ':' + cars[j][prop] + '<br>';
}
if(j!=cars.length-1) {
resultMsg.innerHTML += '<hr>';
}
}
}
else if(result.length==0) {
resultMsg.innerHTML = "No results were found meeting criteria";
}
}
//filtering function, removes from result array those cars that do not meet given criteria
function filter(filter) {
switch(filter) {
case "firstOwner": {
if(getData.firstOwner == 'on') {
for(var x=result.length-1;x>=0;x--) {
if(result[x].owners != 1) {
result.splice(x,1);
}
}
}
} break;
case "fuelType": {
if(getData.fuelType == 'diesel') {
for(var x=result.length-1;x>=0;x--) {
if(result[x].fuelType != 'Diesel') {
result.splice(x,1);
}
}
}
else if(getData.fuelType == 'petrol') {
for(var x=result.length-1;x>=0;x--) {
if(result[x].fuelType != 'Petrol') {
result.splice(x,1);
}
}
}
} break;
case "priceMin": {
if(getData.priceMin != "") {
for(var x=result.length-1;x>=0;x--) {
if(result[x].price<getData.priceMin) {
result.splice(x,1);
}
}
}
} break;
case "priceMax": {
if(getData.priceMax != "") {
for(var x=result.length-1;x>=0;x--) {
if(result[x].price>getData.priceMax) {
result.splice(x,1);
}
}
}
} break;
case "engineSize": {
if(getData.engineSize != 'all') {
var eSMin = -1;
var eSMax = -1;
switch(getData.engineSize) {
case "0": {
eSMin=0;
eSMax=999;
} break;
case "1": {
eSMin=1000;
eSMax=1399;
} break;
case "2": {
eSMin=1400;
eSMax=1699;
} break;
case "3": {
eSMin=1700;
eSMax=1999;
} break;
case "4": {
eSMin=2000;
eSMax=2999;
} break;
case "5": {
eSMin=3000;
eSMax=99999;
} break;
}
for(var x=result.length-1;x>=0;x--) {
if(result[x].engineSize<eSMin || result[x].engineSize>eSMax) {
result.splice(x,1);
}
}
}
} break;
case "transmission": {
if(getData.transmission == "manual") {
for(var x=result.length-1;x>=0;x--) {
if(result[x].transmission!='Manual') {
result.splice(x,1);
}
}
}
else if(getData.transmission == 'automatic') {
for(var x=result.length-1;x>=0;x--) {
if(result[x].transmission!='Automatic') {
result.splice(x,1);
}
}
}
} break;
case "mileageMin": {
if(getData.mileageMin != "") {
for(var x=result.length-1;x>=0;x--) {
if(result[x].mileage<getData.mileageMin) {
result.splice(x,1);
}
}
}
} break;
case "mileageMax": {
if(getData.mileageMax != "") {
for(var x=result.length-1;x>=0;x--) {
if(result[x].mileage>getData.mileageMax) {
result.splice(x,1);
}
}
}
} break;
default: {
alert("Unknown filter.");
}
}
if(result == "") {
resultMsg.innerHTML += "No results were found meeting criteria.";
}
return result;
}
function availableFilters() {
var formElems = document.getElementsByTagName("form")[0].elements;
if(formElems!=null) {
for(var d=0;d<formElems.length;d++) {
if(formElems[d].type == 'number' || formElems[d].type == 'select-one' || formElems[d].type == 'radio' ||
formElems[d].type == 'checkbox' || formElems[d].type == 'text') {
filterSet.push(formElems[d].name);
}
}
}
else {
alert("Couldn't find any form elements");
}
// make sure we have only unique values in a filters array
filterSet = filterSet.filter(function(item, pos) {
return filterSet.indexOf(item) == pos;
});
// console.log("number of filters after unique checking: " + filterSet.length);
}
function showFilters(filterSet) {
if(filterSet.length!=0) {
for(var c=0;c<filterSet.length;c++) {
console.log('filterSet(' + c + ') :' + filterSet[c]);
}
}
else {
alert("no filters to show!");
}
}
/*
Checks if any filters were set and if so then apply filters
*/
function filterCars(filterSet = null) {
if(filterSet == null) {
resultMsg.innerHTML = "No filters were passed";
}
else {
for(var f=0;f<filterSet.length;f++) {
if(filter(filterSet[f]) == "") {
return 0;
}
}
}
}
function prepareForm() {
var form = document.getElementsByTagName('form')[0];
if(form.addEventListener) { //modern browsers
form.addEventListener('submit', function(e) {
// getRequest(form.getAttribute('action'));
// run();
}, false);
}
else if(form.attachEvent) { //old IE
form.attachEvent('onsubmit', function(e) {
// e.preventDefault();
// getRequest('index.php');
// run();
});
}
}
function initialize() {
//JSON objects that will be merged together and used as a source of cars
mergeJSON(cars,models,"modelId");
//create a 'copy' of cars object that can't be modified
result = JSON.parse(JSON.stringify(cars));
availableFilters();
filterCars(filterSet);
}
//prepareForm() need to be always executed before 'run()'
// prepareForm();
initialize();
function run() {
printCars(result);
console.log(result);
}
run();
//---------- if the form has been submitted -------------------------------------------------------------------------------
});
}());
JavaScript 
Choć podczas rozmowy telefonicznej uzgodniliśmy ze będę musiał się podszkolić z bibliotek/frameworkow których nie znam. Będę wdzięczny za wszelkie wskazówki, chce popracować nad sobą.
Maciej Cąderek