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How to extract data from JSON object

I am using Google Script to fetch an url that returns me the following JSON object:
[
{
"rsid":"op-bigideas",
"site_title":"Big Ideas",
"evars":[
{
"name":"Tracking Code",
"type":"text_string",
"id":"trackingcode",
"expiration_type":"week",
"expiration_custom_days":"1",
"allocation_type":"most_recent_last"
},
{
"name":"Custom eVar 1",
"description":"",
"type":"text_string",
"enabled":false,
"id":"evar1",
"expiration_type":"visit",
"expiration_custom_days":1,
"allocation_type":"most_recent_last"
}
]
}
]
How can I extract the name property from evars using javascript with Google Apps Script?
This is the code that returns me the JSON object:
var elements = JSON.parse(UrlFetchApp.fetch(url, options));
I already tried the following but only receiving undefined message:
1.
for(var elem in elements) {
Logger.log(elements[elem]['evars'].name);
}
2.
for(var elem in elements) {
Logger.log(elements[elem].evars.name);
}
3.
var newData = JSON.parse(elements);
Logger.log(newData.evars.name)

If I understand you correctly, you want to get the values of the name properties. This code will log the name properties:
for (var elem in elements) {
for (var evar in elements[elem].evars) {
Logger.log(elements[elem].evars[evar].name);
}
}
This will output:
"Tracking Code"
"Custom eVar 1"

There are multiple name properties for each element, so I think you want to map twice:
elements.map(function(elt) {
return !elt.evars ? [] : elt.evars.map(function(evar) {
return evar.name;
});
});
This will give you an array of arrays; the outer array is the elements, each of which contains an array of the names. For your example, this will be:
[
["Tracking Code", "Custom eVar 1"]
]

for (var elem in elements[0].evars) {
Logger.log(elements[0].evars[elem].name);
}

Angular.js group by sub property

I have such JSON file:
{
"dates":
[
{
"day": "Monday",
"shifts": [
{
"shift-name": "shift 1",
"assignments": [
{
"position-name": "supervisor",
"location-name": "Location 2",
"persons": [
{
"person-name": "USI, ANTHONY RN"
}
]
},
{
"position-name": "driver(s?)",
"location-name": "LOCATION 1",
"persons": [
{
"person-name": "LOVELAND, VIVIENNEW"
},
{
"person-name": "LOVELAND, VIVIENNEW"
}
]
}...
And I need to create a loop using this JSON. But I need to make it in a way that all persons are grouping by location-name. But I don't know how to do it as location name could be duplicated. So the structure should be like this:
Date
Location1
Shift1
Supervisors
Drivers
Shift2
Supervisors
Drivers
Location2
Shift1
Supervisors
Drivers
Shift2
Supervisors
Drivers
Thank you!

For example I take abstract test.json file with your structure. And get the data form XmlHttpRequest:
var xhr = new XMLHttpRequest();
xhr.open("GET", 'test.json', true);
xhr.onload = function(){
// get result
var data = JSON.parse(xhr.responseText);
// result
var result = {};
// go loop!
data.dates.forEach(function(day){
// check if day exists
result[day.day] = result[day.day] || {};
day.shifts.forEach(function(shift){
shift.assignments.forEach(function(assignment){
//check if location exists
result[day.day][assignment['location-name']] = result[day.day][assignment['location-name']] || {};
// ... if shift exists in this location
result[day.day][assignment['location-name']][shift['shift-name']] = result[day.day][assignment['location-name']][shift['shift-name']] || {};
// ... if position-name exists in this location -> shift
result[day.day][assignment['location-name']][shift['shift-name']][assignment['position-name']] = result[day.day][assignment['location-name']][shift['shift-name']][assignment['position-name']] || [];
// ... push persions in position-name array
assignment.persons.forEach(function(person){
result[day.day][assignment['location-name']][shift['shift-name']][assignment['position-name']].push(person);
})
});
});
});
// print result
console.log(result)
};
xhr.send();

You need to map this data to a new flatter structure that represents what you want to use it for
Generally the best way to approach something like this is to create a temporary object that uses the common value as keys. Then push items to array(s) based on those keys.
So first you would iterate dates.
Within each iteration of dates create an empty object.
Then you would loop over assignments creating object keys using location-name values as keys.
That object would look something like:
{
"Location 1":{"supervisors":[], "drivers":[]},
"Location 2":{"supervisors":[], "drivers":[]}
}
Then as you iterate over persons you use "position-name" to determine which array to push to. That step would look something like:
Finally you iterate that object to create the arrays needed for locations for that date and the dates loop continues and repeats process in next iteration

Access the nested value in JSON without looping through it

This is my JSON, I want to directly get the zipCodes values from the JSON without looping through the JSON. How can I do it?
countries:[
{
name:'India',
states:[{
name:'Orissa',
cities:[{
name:'Sambalpur',
zipCodes:{'768019','768020'}
}]
}]
}
]

I think you are looking for
countries[0].states[0].cities[0].zipCodes
Please note, this works for the above JSON as there is only 1 country in countries array and same as for states and cities. However, if there are more than 1 country, state or city then, you will have to iterate to extract information until and unless you know the exact index.

As this is not an associative array, your option is only to use indexes like this:
countries[x].states[y].cities[0].zipCodes
Where x would be each representation of state in your array, in case, of course, that you have more than one.
Similarly y would be each state in each state in each country, in case you have more of those and you can do the same for cities if you need to.
EDIT:
Here's how you can iterate the array:
for(var c in countries)
{
var name = countries[c].name;
if (name === "CountryIAmLookingFor")
{
var statesList = countries[c].states;
for (var s in statesList)
{
var stateName = statesList[s].name;
.....
}
}
}
You can keep iterating until you find the country, state, and city you need, then extract the zipCodes from there as shown in the previous code snippet.

Without "looping"
You can do this crazy trick (not saying this is the best way, but this way you aren't looping through the JSON):
var myData = { 'Put Your Data': 'HERE' };
function getCodes(name, data) {
var sv = data.match(new RegExp(name+'([\\S\\s]*?}][\\S\\s]*?}])'))[1].match(/zipCodes":\[(.*?)\]/g), r = [];
sv.forEach(function (item) {
item.match(/\d+/g).forEach(function (sub) {
r.push(+sub);
});
});
return r;
}
getCodes('India', JSON.stringify(myData));
If your data is already string, then you don't need the JSON.stringify. The forEach you see isn't actually "looping" through the JSON. It's already extracted the zip codes and the code just adds the zip codes to the array. . This line:
var sv = JSON.stringify(data).match(new RegExp(name+'([\\S\\s]*?}][\\S\\s]*?}])'))[1].match(/zipCodes":\[(.*?)\]/g), r = [];
is what grabs the zip codes, it gets something like:
["zipCodes":["768019","768020"]"]
The next line:
item.match(/\d+/g)
will grab the numbers outputting something like:
["768019", "768020"]
The loop just adds the zip-codes to another array
With looping
You're better off looping through the JSON:
var myData = {}, // Your data
zips = [];
myData.countries.forEach(function(i) {
if (i.name === 'India') {
i.states.forEach(function(j) {
j.cities.forEach(function(l) {
l.zipCodes.forEach(function(m) {
zips.push(m);
});
});
});
}
});
//use "zips" array
PERFORMANCE AND SPEED TESTS
After testing copying an array about 500MB (half a gig) took about 30 seconds. That's a lot. Considering an extremely large JSON would be about ~5MB, looping through a little over 5MB of JSON takes about 0.14 seconds. You should never worry about speed.

Here's my "trick" for avoiding explicit iteration. Let JSON.parse or JSON.stringify do the work for you. If your JSON is in string form, try this:
var array = [];
JSON.parse(jsonString, function (key, value) {
if (key === "zipCodes") {
array = array.concat(value);
}
return value;
});
console.log(array); // all your zipCodes

Suppose your Json is like
countries =[
{
name:'India',
states:[{
name:'Orissa',
cities:[{
name:'Sambalpur',
zipCodes:768019768020
}]
},{
name:'mumbai',
cities:[{
name:'rea',
zipCodes:324243
}]
}]
}
]
So now we use MAP it will give you ZipCode of every cities
countries.map(function(s){
s.states.map(function(c){
c.cities.map(function(z){
console.log(z.zipCodes)
})
})
})
OR
If you use return statement then it will give you 2 array with two zip code as per over JSON
var finalOP = countries.map(function(s){
var Stalist = s.states.map(function(c){
var zip = c.cities.map(function(z){
return z.zipCodes
})
return zip
})
return Stalist
})
console.log(finalOP)

Best way to store this data (array, object, etc)

I need to store (many) objects or arrays of data, which need to have the following criteria:
I need to be able to add a new set of data into the existing data easily
I need to be able to sort the data by date/ time added easily (array in order of when entries were pushed to it)
I need to be able to grab an entry easily using a reference, either integer or string. This is important, at the moment I have to do an $.each() to loop through my data until I find the entry I want.
I have tried using a structure like:
saved_info = {
1001: {//all my data for ref 1001},
1002: {//all my data for ref 1002}
}
which gave me what wanted of being able to grab the info easily given a reference:
info = saved_info[1001];
however, the reference numbers I use aren't in order - I use a reference given to me (its a unique identifier), therefore the object isn't in order of when items were added/saved/pushed.

You can use two objects:
One that stores the data by key
Another that stores the sort order
This way you can (i) lookup an element by key (ii) loop over elements in the order they were inserted. Rough outline of the structure:
var DataObject = {
data: {},
sort: []
};
Here is how you add data to this structure:
DataObject.data[1004] = {name: "Test 4"};
DataObject.sort.push(1004);
DataObject.data[1001] = {name: "Test 1"};
DataObject.sort.push(1001);
DataObject.data[1003] = {name: "Test 3"};
DataObject.sort.push(1003);
DataObject.data[1002] = {name: "Test 2"};
DataObject.sort.push(1002);
Here is how you perform a random access:
console.log(DataObject.data[1001].name);
console.log(DataObject.data[1003].name);
And here is how you iterate over all elements in the order they were added:
var i;
for (i = 0; i < DataObject.sort.length; i++) {
console.log(DataObject.data[DataObject.sort[i]].name);
}
It is possible to wrap the entire logic inside a class:
function DataObject() {
this.data = {};
this.sort = [];
this.setItem = function (k, v) {
this.data[k] = v;
this.sort.push(k);
};
this.getItemByKey = function (k) {
return this.data[k];
};
this.getItemByPos = function (i) {
return this.data[this.sort[i]];
};
this.getAllItems = function () {
var i, r = [];
for (i = 0; i < this.sort.length; i++) {
r.push(this.data[this.sort[i]]);
}
return r;
};
}
var t = new DataObject();
t.setItem(1001, {name: "Test 1"});
t.setItem(1002, {name: "Test 2"});
t.setItem(1003, {name: "Test 3"});
t.setItem(1004, {name: "Test 4"});
console.log(t.getItemByKey(1001));
console.log(t.getItemByPos(0));
console.log(t.getAllItems());

Try to build a Json like this,
var xJson = {
"1001":{//all my data for ref 1001},
"1002":{//all my data for ref 1002}
};
and you can fetch the records as per your wish using the bracket notation, since we are using a numeric value as a key.
var xData = xJson["1001"];

Ordered JSONObject

I have a servlet which talks with the database then returns a list of ordered (ORDER BY time) objects. At the servlet part, I have
//access DB, returns a list of User objects, ordered
ArrayList users = MySQLDatabaseManager.selectUsers();
//construct response
JSONObject jsonResponse = new JSONObject();
int key = 0;
for(User user:users){
log("Retrieve User " + user.toString());
JSONObject jsonObj = new JSONObject();
jsonObj.put("name", user.getName());
jsonObj.put("time", user.getTime());
jsonResponse.put(key, jsonObj);
key++;
}
//write out
out.print(jsonResponse);
From the log I can see that the database returns User objects in the correct order.
At the front-end, I have
success: function(jsonObj){
var json = JSON.parse(jsonObj);
var id = 0;
$.each(json,function(i,item) {
var time = item.time;
var name = item.name;
id++;
$("table#usertable tr:last").after('<tr><td>' + id + '</td><td width="20%">' + time +
'</td><td>' + name +
'</td></tr>');
});
},
But the order is changed.
I only noticed this when the returned list has large size (over 130 users).
I have tried to debug using Firebug, the "response tab" in Firebug shows the order of the list is different with the log in the servlet.
Did i do anything wrong?
EDIT: Example
{"0":{"time":"2011-07-18 18:14:28","email":"xxx#gmail.com","origin":"origin-xxx","source":"xxx","target":"xxx","url":"xxx"},
"1":{"time":"2011-07-18 18:29:16","email":"xxx#gmail.com","origin":"xxx","source":"xxx","target":"xxx","url":"xxx"},
"2":
,...,
"143":{"time":"2011-08-09 09:57:27","email":"xxx#gmail.com","origin":"xxx","source":"xxx","target":"xxx","url":"xxx"}
,...,
"134":{"time":"2011-08-05 06:02:57","email":"xxx#gmail.com","origin":"xxx","source":"xxx","target":"xxx","url":"xxx"}}

As JSON objects do not inherently have an order, you should use an array within your JSON object to ensure order. As an example (based on your code):
jsonObj =
{ items:
[ { name: "Stack", time: "..." },
{ name: "Overflow", time: "..." },
{ name: "Rocks", time: "..." },
... ] };
This structure will ensure that your objects are inserted in the proper sequence.
Based on the JSON you have above, you could place the objects into an array and then sort the array.
var myArray = [];
var resultArray;
for (var j in jsonObj) {
myArray.push(j);
}
myArray = $.sort(myArray, function(a, b) { return parseInt(a) > parseInt(b); });
for (var i = 0; i < myArray.length; i++) {
resultArray.push(jsonObj[myArray[i]]);
}
//resultArray is now the elements in your jsonObj, properly sorted;
But maybe that's more complicated than you are looking for..

As mentioned by ghayes , json objects are unordered.
There are multiple solutions to this problem.
You can use array and the sort it to get the ordered list.
You can use gson library to get the desired order of elements.
I would prefer the second option as it is easy to use.

As JSONObject is order less and internally uses Hashmap. One way to use it to download the all classes from org.json and use in your project directly by changing the internal HashMap implementation to LinkedHashMap in JSONObject.java file. below is the sorted json files
https://github.com/abinash1/Sorted-Json-Object