Develop Reference

get previous json item in Json

I have a JSON file titled stuff.json. I am trying to get the previous json item given a certain item. For example, if I am given the key ["also-random-here"], how do I get the previous JSON item "sample-name"?
My JSON data looks as follows:
{
"random-name-here": {
"name": "name is item1"
},
"sample-name": {
"name": "name is item2"
},
"also-random-here": {
"name": "name is item3"
}
}

try this
var names={
"random-name-here": {
"name": "name is item1"
},
"sample-name": {
"name": "name is item2"
},
"also-random-here": {
"name": "name is item3"
}
};
var prevName= findPrevName(names, "also-random-here") ;
function findPrevName(item, key) {
var prevName;
for (const property in item)
{
if(property==key) break;
prevName=property;
};
return { [prevName]: item[prevName]};
};

filter result using 2 JSON

This is my saved localstorage,
[{"industry_Id":1,"merchant_id":2}]
I want to filter below result, to get HP.
{
"industries": [
{
"id": 1,
"name": "oil and gas",
"merchant": [
{
"id": 1,
"name": "ABC",
},
{
"id": 2,
"name": "DEF",
},
{
"id": 3,
"name": "GHJ",
}
]
},
{
"id": 2,
"name": "IT",
"merchant": [
{
"id": 1,
"name": "Apple",
},
{
"id": 2,
"name": "HP",
},
{
"id": 3,
"name": "Google",
}
]
}
]
}
I thought of using multiple $.each but it have to iterate few times and it's quite redundant.

I would prefer using Javascript for loop, that way you can skip iterating over every object once required element is found.
Without jQuery (using for)
var i, j, merchant = null;
for(i = 0; i < data['industries'].length; i++){
if(data['industries'][i]['id'] == arg[0]['industry_Id']){
for(j = 0; j < data['industries'][i]['merchant'].length; j++){
if(data['industries'][i]['merchant'][j]['id'] == arg[0]['merchant_id']){
merchant = data['industries'][i]['merchant'][j];
break;
}
}
if(merchant !== null){ break; }
}
}
With jQuery (using $.each)
var merchant_found = null;
$.each(data['industries'], function(i, industry){
if(industry['id'] == arg[0]['industry_Id']){
$.each(industry['merchant'], function(i, merchant){
if(merchant['id'] == arg[0]['merchant_id']){
merchant_found = merchant;
}
return (!merchant_found);
});
}
return (!merchant_found);
});
var arg = [{"industry_Id":1,"merchant_id":2}];
var data = {
"industries": [
{
"id": 1,
"name": "oil and gas",
"merchant": [
{
"id": 1,
"name": "ABC",
},
{
"id": 2,
"name": "DEF",
},
{
"id": 3,
"name": "GHJ",
}
]
},
{
"id": 2,
"name": "IT",
"merchant": [
{
"id": 1,
"name": "Apple",
},
{
"id": 2,
"name": "HP",
},
{
"id": 3,
"name": "Google",
}
]
}
]
};
var i, j, merchant = null;
for(i = 0; i < data['industries'].length; i++){
if(data['industries'][i]['id'] == arg[0]['industry_Id']){
for(j = 0; j < data['industries'][i]['merchant'].length; j++){
if(data['industries'][i]['merchant'][j]['id'] == arg[0]['merchant_id']){
merchant = data['industries'][i]['merchant'][j];
break;
}
}
if(merchant !== null){ break; }
}
}
console.log(merchant);
document.writeln("<b>Without jQuery:</b><br>");
document.writeln((merchant !== null) ? "Found " + merchant['name'] : "Not found");
var merchant_found = null;
$.each(data['industries'], function(i, industry){
if(industry['id'] == arg[0]['industry_Id']){
$.each(industry['merchant'], function(i, merchant){
if(merchant['id'] == arg[0]['merchant_id']){
merchant_found = merchant;
}
return (!merchant_found);
});
}
return (!merchant_found);
});
console.log(merchant_found);
document.writeln("<br><br><b>With jQuery:</b><br>");
document.writeln((merchant_found) ? "Found " + merchant_found['name'] : "Not found");
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

selectors.map(function(selector) {
return data.industries.filter(function(industry) {
return industry.id == selector.industry_Id;
})[0].merchant.filter(function(merchant) {
return merchant.id == selector.merchant_id;
})[0].name;
});
// => DEF
If you want "HP", you want industry 2, not industry 1.
.filter(...)[0] is not really optimal. You could use .find(...), but that is not yet universally supported. Or you could use plain old JavaScript and write for loops instead to make it fast. Or you could use objects with ID keys instead of arrays to make lookups faster.

When it comes into a position where collection of data is what you're processing, I suggest you to take a look at underscore.js. It's not optimal choice for the best performance but it does make you code more readable and makes more sense especially when compared with loop.
Say data is a variable which stores your JSON data.
Try this:
// Given this selector criteria
var select = [{"industry_Id":1,"merchant_id":2}];
function filterByCriteria(criteria, data){
var match = [];
_.each(criteria, function(crit){
function matchIndustry(rec){ return rec.id===crit.industry_Id }
function matchMerchant(rec){ return rec.id===crit.merchant_id }
// Filter by industry id
var industry = _.first(_.where(data.industry, matchIndustry));
// Filter by merchant id
var merchant = _.where(industry.merchant, matchMerchant);
_.each(merchant, function addToMatchResult(m){
match.push(m.name);
});
});
return match;
}
var filteredData = filterByCriteria(select, data);
From snippet above, any merchants which match the search criteria will be taken to the match list. Is it more readable to you?

Do you even need numerical id's? Gets super easy when you don't.
/*
{
"industry": {
"oil and gas":{
"merchant": {
"ABC": {
"name": "ABC oil"
},
"DEF": {
"name": "DEF gas"
},
"GHJ" :{
"name": "GHJ oil and gas"
}
}
},
"IT": {
"merchant": {
"Apple" : {
"name": "Apple computers"
},
"HP": {
"name": "Hewlett Packard"
},
"Google": {
"name": "Google. Maw haw haw"
}
}
}
}
}
*/
var data = '{"industry": {"oil and gas":{"merchant": {"ABC": {"name": "ABC oil"},"DEF": {"name": "DEF gas"},"GHJ" :{"name": "GHJ oil and gas"}}},"IT": {"merchant": {"Apple" : {"name": "Apple computers"},"HP": {"name": "Hewlett Packard"},"Google": {"name": "Google. Maw haw haw"}}}}}';
data = JSON.parse(data);
var merchant = data.industry['IT'].merchant['HP'];
alert(merchant.name);
//console.log(merchant.name);

How to read array inside JSON Object this is inside another array

I am newbie to JSON, I am parsing a JSON Object and i was struck at a point where i have to read the array Elements inside a Object, that is again in another array..
Here is MY JSON
{
"DefinitionSource": "test",
"RelatedTopics": [
{
"Result": "",
"Icon": {
"URL": "https://duckduckgo.com/i/a5e4a93a.jpg"
},
"FirstURL": "xyz",
"Text": "sample."
},
{
"Result": "",
"Icon": {
"URL": "xyz"
},
"FirstURL": "xyz",
"Text": "sample."
},
{
"Topics": [
{
"Result": "",
"Icon": {
"URL": "https://duckduckgo.com/i/10d02dbf.jpg"
},
"FirstURL": "https://duckduckgo.com/Snake_Indians",
"Text": "sample"
},
{
"Result": "sample",
"Icon": {
"URL": "https://duckduckgo.com/i/1b0e4eb5.jpg"
},
"FirstURL": "www.google.com",
"Text": "xyz."
}
]
}
]
}
Here I need to read URL ,FIRSTURL and Text from RelatedTopics array and Topics array..
Can anyone help me. Thanks in advance.

Something like this
function (json) {
json.RelatedTopics.forEach(function (element) {
var url = element.Icon ? element.Icon.URL : 'no defined';
var firstURL = element.FirstURL ? element.FirstURL : 'no defined';
var text = element.Text ? element.Text : 'no defined';
alert("URL: " + url + "\nFirstURL: " + firstURL + "\nText: " + text);
if (element.Topics)
{
element.Topics.forEach(function (topicElement) {
alert("Topics - \n" + "URL: " + topicElement.Icon.URL + "\nFirstURL: " + topicElement.FirstURL + "\nText: " + topicElement.Text);
});
}
});
};
Look fiddle example

Loop through json Array like,
for(var i=0; i< RelatedTopics.length;i++){
if($.isArray(RelatedTopics[i])){
for(var j=0; j< RelatedTopics[i].Topics.length;j++){
var topics=RelatedTopics[i].Topics[j];
var text = topics.Text;
var firsturl = topics.Firsturl;
var url = topics.Icon.url;
}
}
}
if you want push it an array variable

Javascript passing variables

Okay so, I'm trying to get the facebook name and email of a user (succeed in that), and then use mandrill to email me that info. But for some reason, can't seem to get the name and email address to pass into the params object. (I deleted a lot of the facebook login stuff to make it clearer) Help!!
$(function() {
function getCurrentUserInfo() {
FB.api('/me', function(userInfo) {
console.log(userInfo.name + ': ' + userInfo.email);
temp = userInfo.email;
name = userInfo.name;
var needed = {
"name": userInfo.name,
"email": userInfo.email
}
function log(obj) {
$('#response').text(JSON.stringify(obj));
}
var m = new mandrill.Mandrill('key');
// create a variable for the API call parameters
var params = {
"message": {
"from_email":"emailf",
"to":[{"email":"emailg"}],
"subject": "New email",
"html": "*|NAME|* has the email *|EMAIL|* ",
"autotext": "true",
"track_opens": "true",
"track_clicks": "true",
"merge_vars": [
{
"rcpt": "emailrep",
"vars": [
{
"name": "NAME",
"content": "needed["name"]"
},
{
"name": "EMAIL",
"content": "needed["email"]"
}
]
}
]
}
};

You're passing strings when you need the variable:
"vars": [
{
"name": "NAME",
"content":needed["name"]
},
{
"name": "EMAIL",
"content": needed["email"]
}
]

Get Child JSON Values from Objects

I have an endpoint with two JSON Objects as follows:
{
"main" {
"id": 1,
"title": Main Title,
},
{
"secondary" {
"id": 3,
"title": Secondary Title,
},
I am using backbone and have the following $each function, but using dot notation, I can't seem to be able to browse to the titles (ex. main.title or secondary.title). What am I missing?
var collection = new contentArticles([], { id: urlid });
collection.fetch({
dataType: "json",
success: function (model, response) {
console.log(response);
$.each(response, function (index, value) {
console.log(value.main.title);
$("#test2").append('<li>' + value.main.title + '</li>');
});
In my console, it gives an error of: Uncaught TypeError: Cannot read property 'title' of undefined

Assuming your JSON is actually valid when returned (it isn't valid the way you show it), try
$("#test2").append('<li>' + value.title + '</li>');
Your actual JSON should look like:
{
"main": {
"id": 1,
"title": Main Title,
},
"secondary": {
"id": 3,
"title": Secondary Title,
}
}
If you just want the value of main, instead of using $.each(), remove that entire block and do:
$("#test2").append('<li>' + response.main.title + '</li>');
And your final code would look something like:
var collection = new contentArticles([], { id: urlid });
collection.fetch({
dataType: "json",
success: function (model, response) {
console.log(response);
if (response.main.title !== 'undefined'){
$("#test2").append('<li>' + value.main.title + '</li>');
}else{
console.log('Main is undefined');
}
}
});
Final Edit: It looks like you want JSON like:
{
"main": [{
"id": 1,
"title": "Main Title"
}, {
"id": 2,
"title": "Main Title 2"
}, {
"id": 3,
"title": "Main Title 3"
}],
"secondary": [{
"id": 5,
"title": "Secondary Title 5"
}, {
"id": 34,
"title": "Secondary Title 34"
}, {
"id": 36,
"title": "Secondary Title 36"
}]
}
If that is the case your code would look like:
var collection = new contentArticles([], { id: urlid });
collection.fetch({
dataType: "json",
success: function (model, response) {
console.log(response);
$.each(function(index, value){
$.each(item_index, item_value){
$("#test2").append('<li>' + item_value.title + '</li>');
}
});
}
});

The problem lies with input JSON, it should be
{
"main" :{
"id": 1,
"title": "Main Title"
},
"secondary":{
"id": 3,
"title": "Secondary Title"
}
}