I am having trouble to display the top tracks of a searched artist using the LastFM api to get data. The api returns an object toptracks. I would like to grab details about each of the top tracks from that api data.
I am not sure if I am on the right track. Can someone take a look and let me know if I am doing something wrong?
Sample data from api:
{
"toptracks": {
"track": [{
"name": "Best I Ever Had",
"playcount": "3723918",
"listeners": "1086968",
"mbid": "00bde944-7562-446f-ad0f-3d4bdc86b69f",
"url": "https://www.last.fm/music/Drake/_/Best+I+Ever+Had",
"streamable": "0",
"artist": {
"name": "Drake",
"mbid": "b49b81cc-d5b7-4bdd-aadb-385df8de69a6",
},
"#attr": {
"rank": "1"
}
},
{
"name": "Forever",
"playcount": "1713492",
"listeners": "668998",
"url": "https://www.last.fm/music/Drake/_/Forever",
"streamable": "0",
"artist": {
"name": "Drake",
"mbid": "b49b81cc-d5b7-4bdd-aadb-385df8de69a6",
},
"#attr": {
"rank": "2"
}
}
}
function renderTracks(trackArray) {
function createHTML(track){
return `<h1>${track.name}</h1>
<h2>${track.artist[0]}</h2>
<h3>${toptracks[1].rank}</h3>
<h3>${track.playcount}</h3>`;
};
trackHTML = trackArray.map(createHTML);
return trackHTML.join("");
};
var searchString = $(".search-bar").val().toLowerCase();
var urlEncodedSearchString = encodeURIComponent(searchString);
const url = "lastFMwebsite"
axios.get(url + urlEncodedSearchString).then(function(response) {
// createHTML.push(response.data.track);
// $(".tracks-container").innerHTML = renderTracks(response.data.track);
// comented out old code above
createHTML.push(response.toptracks.track);
$(".tracks-container").innerHTML = renderTracks(response.toptracks.track);
})
I've notice that you have not parsed the response:
axios.get(url + urlEncodedSearchString).then(function(response) {
var parsed = JSON.parse(response);
$(".tracks-container").innerHTML = renderTracks(parsed.toptracks.track)
});
Another correction that I can suggest is to change the track.artist[0] to track.artist["name"] once this property returns an object instead of an array.
And about this: <h3>${toptracks[1].rank}</h3>. You will be not able to access that property because at your function you are providing just the trackproperty.
In this case you have two options: provide the whole response array or add a new parameter providing this.
function renderTracks(trackArray) {/**...*/};
//...
$(".tracks-container").innerHTML = renderTracks(parsed.toptracks)
Or
function renderTracks(trackArray, toptracks) {/**...*/};
//...
$(".tracks-container").innerHTML = renderTracks(parsed.toptracks.track, parsed.toptracks)
I hope this can help you :)
Your input JSON is not valid. You'll need to format it correctly. Once the data is correct:
createHTML.push(response.toptracks.track[0])
or
let i = 0;
for(; i < response.toptracks.track.length; i++){
createHTML.push(response.toptracks.track[i]);
}
I have 3 different jsons, I need to extrapolate some data from each and create a new json with it. The three jsons have an id identifier in common, a unique identifier, so We could use that as a match since they are actually three different big jsons.
On json one we have "id":"265", on two and three "article_id":"265", so these can be the reference point when we loop.
I never worked with json this way so I wouldn't know how to approach it. I have put jQuery and JS as tags as they're what I know best.
1
{
"id":"265",
"title":"Battle of Gettysburg",
"page_id":"4849",
"language_id":"en",
"original_time":"July 1\u20133, 1863"
}
2
{
"id":"185",
"original_name":"United States",
"country_id":"24",
"article_id":"265"
}
3
{
"id":"73",
"month":"July",
"year":"1863",
"suffix":"",
"article_id":"265"
}
So the end result I am looking for is a single json exactly like this, we take id and title as objects from json 1, then we grab original_name from json two and year object from json three and we'll have:
{
"id":"265",
"title":"Battle of Gettysburg",
"original_name":"United States",
"year":"1863"
}
NOTE
The json above are just examples, in reality they are three huge lists, what I could do (manually), is to join them in order to have a single json.
There is some terminology confusion here; based on your comments you could be asking one of two very different questions. Fortunately one of them is very simple to answer so let's do both.
(I am handwaving past the details of loading json strings into the browser and converting them into javascript objects.)
If you have three objects
...then this is just a matter of plucking out the fields you need individually when constructing an output object:
var in1 = {
"id": "265",
"title": "Battle of Gettysburg",
"page_id": "4849",
"language_id": "en",
"original_time": "July 1\u20133, 1863"
};
var in2 = {
"id": "185",
"original_name": "United States",
"country_id": "24",
"article_id": "265"
}
var in3 = {
"id": "73",
"month": "July",
"year": "1863",
"suffix": "",
"article_id": "265"
}
// construct a new object using the selected fields
// from each object in1, in2, or in3:
var out = {
id: in1.id,
title: in1.title,
original_name: in2.original_name,
year: in3.year
}
console.log(out);
If you have three lists of objects:
...in this case it's a lot more complicated (and a lot more interesting). In this case you would need to match fields from the objects in each list which share the same IDs.
The following is definitely not the most efficient or memory-conserving way to do this; I've spread things out to (hopefully) make it easier to follow what it's doing.
I'm making two assumptions:
within each list, all IDs are unique (meaning you won't have two objects with the same ID in one JSON file)
Every ID will appear in all three lists (meaning you don't need to handle missing fields in output)
/* Again handwaving past loading JSON strings and parsing
them into javascript objects, we'll just start with
three arrays: */
var input1 = [{
"id": "265",
"title": "Battle of Gettysburg",
"page_id": "4849",
"language_id": "en",
"original_time": "July 1\u20133, 1863"
},
{
"id": "1",
"title": "Foo",
"page_id": "123",
"language_id": "en",
"original_time": "July 1\u20133, 1863"
}
];
var input2 = [{
"id": "1",
"original_name": "Bar",
"country_id": "24",
"article_id": "265"
},
{
"id": "265",
"original_name": "United States",
"country_id": "24",
"article_id": "265"
}
]
var input3 = [{
"id": "1",
"month": "July",
"year": "Baz",
"suffix": "",
"article_id": "265"
},
{
"id": "265",
"month": "July",
"year": "1863",
"suffix": "",
"article_id": "265"
}
]
/* It would be much easier to find corresponding IDs
across these arrays if they weren't arrays. We'll
start by converting them into objects keyed by the
item ids: */
var convertArray = function(arr) {
var output = {};
arr.forEach(function(o) {
output[o.id] = o;
});
return output;
}
var obj1 = convertArray(input1);
var obj2 = convertArray(input2);
var obj3 = convertArray(input3);
/* Now if we need to find (say) the object with id "foo", we don't
need to search the whole array, but can just use `obj1["foo"]` or
`obj1.foo`.
The last step is to iterate over the list of IDs and repeatedly
do basically the same thing as in the "if you have three objects"
part above. The only difference is that we need to access the
object with the same ID in each of the input lists: */
var constructOutput = function(in1, in2, in3) {
var output = []; // we'll be outputting a list of objects again.
// step through every ID (assuming in1 contains all of them):
Object.keys(in1).forEach(function(id) {
var obj = {
id: id,
title: in1[id].title,
original_name: in2[id].original_name,
year: in3[id].year
}
output.push(obj);
});
return output;
}
var final = constructOutput(obj1, obj2, obj3)
console.log(final)
Essentially what you have to do is mimic a SQL JOIN using JavaScript objects:
Use JSON.parse() on all three JSON collections to turn them into arrays of objects.
Iterate through JSON 1 objects; for each object...
Iterate through JSON 2 objects, testing if article ID matches the ID from JSON 1 that we are iterating over. Save this object.
Iterate through JSON 3 objects, testing if ID matches the ID of the object we found from JSON 2. Save this object.
After you have all three objects, make a new object literal that contains only the fields you want:
{
Id: obj1.id,
Title: obj1.title,
Original_name: obj2.original_name,
Year: obj3.year
}
Should you want to combine n number of JSON objects, e.g. a list of objects you can take a functional approach and utilise reduce + filter.
const data = [{
"id":"265",
"title":"Battle of Gettysburg",
"page_id":"4849",
"language_id":"en",
"original_time":"July 1\u20133, 1863"
},
{
"id":"185",
"original_name":"United States",
"country_id":"24",
"article_id":"265"
},
{
"id":"73",
"month":"July",
"year":"1863",
"suffix":"",
"article_id":"265"
}];
const final = data.reduce((accu, { id, title }, index, array) => {
// Find any related objects
const matches = array.filter(data => data.article_id === id);
if (matches.length) {
// Flatten them for ease of access. Duplicate keys will override.
const flat = matches.reduce((arr, item) => ({ ...arr, ...item }), [])
// Return new object
return accu.concat({
...flat,
id,
title,
});
}
return accu;
}, []);
console.log(final, '<<')
// Witness
document.getElementById('results').innerHTML = JSON.stringify(final);
<div id="results" style="font-family: Courier; font-size 14px; color: #fff; background: #000; padding: 20px; max-width: 80vw;"></div>
Edited*
Maybe this is what you need?
let arrPages = [{
"id":"265",
"title":"Battle of Gettysburg",
"page_id":"4849",
"language_id":"en",
"original_time":"July 1\u20133, 1863"
}];
let arrArticles = [{
"id":"185",
"original_name":"United States",
"country_id":"24",
"article_id":"265"
},
{
"id":"73",
"month":"July",
"year":"1863",
"suffix":"",
"article_id":"265"
}];
let getResult = (arrInput, arrCompare) => {
let joinedItems = [];
arrInput.forEach(item => {
let newItem = { id: item.id, title: item.title };
arrCompare.forEach(subItem => {
if(subItem.article_id !== undefined && subItem.article_id === item.id){
if(subItem.original_name !== undefined)
newItem.original_name = subItem.original_name;
if(subItem.year !== undefined)
newItem.year = subItem.year;
}
});
joinedItems.push(newItem);
});
return joinedItems;
};
let result = getResult(arrPages, arrArticles);
console.log(result);
In the first part of the code i create a var that has the json data.
To solve the problema i create 2 functions, the order of the creation dosen't metter, the first function getJSONData() take the json data as parameter and return a object filtered by the keys defined in the array keys. The secound function just check if the current key is present in the array of keys, this function could be replaced by the jQuery.inArray() method.
// JSON data
var json = [{
"id":"265",
"title":"Battle of Gettysburg",
"page_id":"4849",
"language_id":"en",
"original_time":"July 1\u20133, 1863"
},
{
"id":"185",
"original_name":"United States",
"country_id":"24",
"article_id":"265"
},
{
"id":"73",
"month":"July",
"year":"1863",
"suffix":"",
"article_id":"265"
}]
// keys that i want
var keys = ["title", "original_name", "year"];
// var that will have the filtered data
var newJSON = getJSONData(json);
console.log(JSON.stringify(newJSON))
// this is the main function of the code
// here we iterate in the json creating a new object that has all the tags definid in the keys array
function getJSONData(arrayJSON){
var JSONFiltered = {};
for(var i in arrayJSON){
for(var key in arrayJSON[i]){
if(hasElement(key)){
JSONFiltered[key] = arrayJSON[i][key];
}
}
}
return JSONFiltered;
}
// this function is used to check a key is present in the array of keys
function hasElement(key){
for(var elem in keys){
if(keys[elem] == key) return true;
}
return false;
}
Up until now I've been using .get() and _.clone() on the array attributes then making my object up before setting the model but this feels completely wrong and I'm not sure how to improve upon this. I feel the array attributes should be transformed into collections but 1) I'm not sure how to do this and 2) I'm not sure of the real benefits compared to my current approach. Can anyone help me improve on my approach? Also note, the POST object needs to be created to be sent via AJAX to a non RESTful service
Example model:
{
"id": 1,
"name": "Joe Bloggs",
"teams": [],
"ageGroups": [],
"categories": []
}
Example of how my data should look when posting back to server
{
"id": 1,
"name": "Joe Bloggs",
"teams": [
{
"id": 123,
"name": "Team One",
"location": "UK"
}, {
"id": 321,
"name": "Team Two",
"location": "USA"
}
],
"ageGroups": ["16", "18", "21"],
"categories": [
{
"id": 45,
"name": "Category One"
}, {
"id": 65,
"name": "Category Two"
}
]
}
A very stripped down example:
var myView = new View({
addToCategory: function() {
var categories = _.clone(this.model.get('categories'));
// Grab values I need from user input...
var categoryDetails = {
"id": userId,
"name": userName
};
this.model.set({
categories: categoryDetails
});
},
addToAgeGroups: function() {
var ageGroups = _.clone(this.model.get('ageGroups'));
// Grab my age group via user input ...
ageGroups.push(newAgeGroup);
this.model.set({
ageGroups: ageGroups
});
}
});
Backbone (intentionally?) does not handle nested data particularly well. After some experience I've resisted the urge to make my Model have an attribute on it that is a Collection, etc. It generally makes things more confusing for little benefit.
I suggest making your Models smarter to handle the array attributes, moving some of the logic in your View into the Model itself. If you really think some parts of your application would like to treat that data as a full-blown Collection, have the Model handle that internally too.
For instance:
var MyModel = Backbone.Model.extend({
getCategories: function() {
if (!this._categoriesCollection) {
var categories = this.get('categories');
this._categoriesCollection = new Backbone.Collection(categories);
}
return this._categoriesCollection;
}
addCategory: function(categoryDetails) {
var currentCategories = this.getCategories();
currentCategories.add(categoryDetails);
}
});
Caching the result of getCategories() means you can ensure there is only ever one instance of the collection of categories. You can add more methods to handle the Parent/Child relationship within the Model, making him the sole owner of that data.
Handling how to POST the data to server seems like a separate question, but generally I've overridden the Model.sync() method to do that sort of thing.
I have an array in Knockout view model which looks like so:
this.Activities = ko.observableArray([
{ "date": "28/11/2012 00:00:00",
"activities": [
{ "company": "BOW",
"description": "Backup Checks",
"length": "60"
},
{ "company": "AMS",
"description": "Data Request",
"length": "135"
},
]},
{ "date": "30/11/2012 00:00:00",
"activities": [
{ "company": "BOW",
"description": "Backup Checks",
"length": "60"
},
{ "company": "SLGT",
"description": "Software Development",
"length": "240"
},
{ "company": "BOW",
"description": "Data Request",
"length": "30"
},
]},
]);
I use this code to add a new element to it:
this.Activities.push(new NewActivity(company, description, length, fullDate));
Which uses NewActivity function:
function NewActivity(company, description, length, date) {
this.date = date;
this.activities = [{ "company": company, "description": description, "length": length }];
}
And it works fine. However, it creates an entirely new object every time it is getting released. I need to implement a condition when the code would check for the date of the objects already created. If the newly created object had the same date, activity details should be added to activities array within the Activities array for that date.
How can I do it?
All of the data for the Activities array comes from the model in the strongly typed view in MVC application:
this.Activities = ko.observableArray([
#foreach (ActivitySet aSet in Model)
{
#:{ "date": "#aSet.Date",
#:"activities": [
foreach(Activity a in aSet.Activities)
{
#:{ "company": "#a.Companies.Select(c => c.Title).Single()",
#:"description": "#a.Descriptions.Select(c => c.Title).Single()",
#:"length": "#a.LengthInMinutes"
#:},
}
#:]},
}
]);
I suggest that you create a few entities describing your activities:
// Details
function ActivityDetails(company, description, length) {
this.company = ko.observable(company);
this.description = ko.observable(description);
this.length = ko.observable(length);
}
// Activity
function Activity(date, activityDetails) {
this.date = ko.observable(date);
this.details = ko.observableArray(activityDetails);
}
The you can control activities in the following manner:
function ViewModel () {
var self = this;
this.Activities = ko.observableArray([
// Activities here
]);
this.addActivity = function (activity) {
var flag = false;
ko.utils.arrayMap(self.Activities(), function (item) {
// Flag is here so it doesn't keep checking further in iterations
if (!flag) {
if (item.date() === activity.date()) {
item.details.push(activity.details);
flag = true;
}
}
});
// Case where activity date was not found in existing records
if (!flag) {
self.Activities.push(activity);
}
}
}
This requires your view model to have a custom add method which I have provided an example of. Note that everywhere I am resolving observable values, so if you are using non-observable ones remove the function calls.
I have a json tree structure that is appended to by pressing invoke on this fiddle : http://jsfiddle.net/adrianjsfiddlenetuser/C6Ssa/4/
Press invoke multiple tiles on the fiddle & copy/paste the produced jSon intohttp://jsonlint.com/, the produced json is not valid
I need to produce this :
{
"nodes": [
{
"url": "asdfas",
"date": ""
},
{
"url": "asdfas",
"date": ""
},
{
"url": "asdfasfdasas",
"date": ""
}
]
}
Can this be amended so that multiple children can be added to the tree structure, I think I need to amend the var data somehow ?
Try:
var data = {nodes: []};
$("#add").on('click', function () {
data.nodes.push({
url: "some url",
date: new Date
});
$("#myDiv").text(JSON.stringify(data));
});
if not, I didn't understand your question ;)
http://jsfiddle.net/gY5yQ/
See if this helps http://jsfiddle.net/C6Ssa/12/
var data = [];
$("#add").click(add);
function add() {
data.push({
param1: "stuff",
param2:1,
param3:1
});
var sample = {};
sample.node = data
$("#myDiv").text(JSON.stringify(sample));
}