Writing from JSON to HTML via JavaScript - javascript

Okay so I have a website that needs to display some data from a JSON file. The file contains different places in Norway with their name (Halden), state number (kommunenummer), number of men (menn) and number of women (kvinner).
I need to write some code that displays every name, state number and the total population of that place (which is the most recent measurement of men + women)
The JSON data looks like this:
"elementer": {
"Halden": {
"kommunenummer": "0101",
"Menn": {
"2016": 15306,
"2017": 15473,
"2018": 15620
},
"Kvinner": {
"2016": 15238,
"2017": 15317,
"2018": 15417
}
}
And so on... The JSON file has a lot of these. The attribute "elementer" is where all the data is stored, so when I open "elementer" in my browser console, I get all of the states listed.
So this is where I need the JSON data to be displayed;
<div id="visOversikt">
<ul>
<li>hei</li>
</ul>
</div>
My JavaScript looks like this:
function load(url, objekt){
var request = new XMLHttpRequest()
request.open('GET', url, true)
request.onreadystatechange = function () {
if(request.readyState === 4 && request.status === 200) {
console.log("Data er lastet inn vellykket...");
}
}
request.onload = function() {
// Begin accessing JSON data here
objekt.data = JSON.parse(this.response)
}
request.send()
}
var befolkning = {
}
load("http://wildboy.uib.no/~tpe056/folk/104857.json", befolkning)
function getNames(data) {
for (var variable in data) {
console.log(variable)
}
function displayOversikt() {
}
}
The function displayOversikt() is where I thought I could write the code to display the data. If anyone can help I would appreciate it. Say I write getNames(befolkning.data.elementer) in the console, I listed all the state names (if it is of any help).

I have done it in simple jquery.
Your html
<html>
<head>
<script src="https://code.jquery.com/jquery-1.10.2.js"></script>
<script src="JsonView.js"></script>
</head>
<body>
<div id="visOversikt">
<ul></ul>
</div>
</body>
</html>
Your jquery(JsonView.js) would be
$(document).ready(function(){
$.getJSON("http://wildboy.uib.no/~tpe056/folk/104857.json", function(json) {
$.each(json['elementer'],function(key,value){
var stateName = key;
var kommunenummer = value['kommunenummer'];
var MennValue = value['Menn']['2018'];
var FemaleValue = value['Kvinner']['2018'];
var addition = MennValue + FemaleValue;
var li = '<li>'+stateName+', '+kommunenummer+', '+addition+'</li>'
$("#visOversikt ul").append(li)
});
});
})

First of all, I would suggest looking at the fetch API. It's a real improvement on the older AJAX style you use.
Then, I would break the problem down into three phases:
Use fetch to get the data
Restructure the data to include exactly what you want
Format each element of that data into HTML
Here's one way that might look:
const output = document.getElementById('output')
const structureTownData = ([name, {kommunenummer, Menn, Kvinner}]) => ({
name,
kommunenummer,
pop: Number(Menn['2018']) + Number(Kvinner['2018'])
})
const formatOutput = ({name, kommunenummer, pop}) => {
const el = document.createTextNode(`${name} (#${kommunenummer}): ${pop}`)
const li = document.createElement('li')
li.appendChild(el);
output.appendChild(li)
}
fetch("http://wildboy.uib.no/~tpe056/folk/104857.json")
.then(resp => resp.json())
.then(({elementer}) => Object.entries(elementer).map(structureTownData))
.then(towns => towns.forEach(formatOutput))
<ul id="output"></ul>
<script>
data = {"elementer":{"Halden":{"kommunenummer":"0101","Menn":{"2016":15306,"2017":15473,"2018":15620},"Kvinner":{"2016":15238,"2017":15317,"2018":15417}},"Oslo kommune":{"kommunenummer":"0301","Menn":{"2016":328424,"2017":332578,"2018":335806},"Kvinner":{"2016":329966,"2017":334181,"2018":337663}}}}
// fake fetch for testing
const fetch = (url) => Promise.resolve(({json: () => data}))
</script>
There are plenty of alternative ways to create your HTML. And you'd have to decide on the exact format you want. Here I just use an unordered list with elements that look like Halden (#0101): 31037.

Already answered here https://stackoverflow.com/a/20135028/5525384
const div = document.getElementById('visOversikt');
function makeList(jsonObject, listElement){
for(var i in jsonObject){
var newLI = document.createElement('li');
if (jsonObject[i] instanceof Array){
newLI.innerHTML=i;
}
else if (jsonObject[i] instanceof Object){
newLI.innerHTML=i;
}
else {
newLI.innerHTML=i+': '+jsonObject[i];
}
listElement.appendChild(newLI)
if (jsonObject[i] instanceof Array || jsonObject[i] instanceof Object){
var newUL = document.createElement('ul');
listElement.appendChild(newUL);
makeList(jsonObject[i],newUL);
}
}
}
makeList(jsonObject, div);

try to use <template> and split data and view
let data = {"elementer":{"Halden":{"kommunenummer":"0101","Menn":{"2016":15306,"2017":15473,"2018":15620},"Kvinner":{"2016":15238,"2017":15317,"2018":15417}},"Moss":{"kommunenummer":"0104","Menn":{"2016":16000,"2017":16085,"2018":16124},"Kvinner":{"2016":16182,"2017":16322,"2018":16464}}}}
function displayOversikt(data) {
let inject = (s,o)=>s.replace(/\${(.*?)}/g,(x,g)=>o[g]); // helper which inject object fields into string in ${filedname}
// Prepare data
let dd= Object.entries(data.elementer).map(([x, y]) => {
let year = Object.keys(y.Menn).sort((a,b)=>+b-a)[0]; // last year
return {
population: y.Menn[year] + y.Kvinner[year],
num: y.kommunenummer,
name: x,
}});
// Read templae string
let t=item.innerHTML;
// Bind data to template and write in content element
content.innerHTML = dd.map(x=> inject(t,x)).join('');
}
displayOversikt(data);
<div ><ul id="content"></ul></div>
<template id="item">
<li>${name}, ${num}, ${population}</li>
</template>

Related

How to render RapidAPI data on another HTML page?

I am new to JavaScript and this is my first question here. I've been trying for week to render my RapidApi data on another HTML page. I made search form on my index page and then put its values as my api call parameters in order to influence my API response. I used fetch to do so. The issue is that my API data keeps rendering on the same index page which is understandable since I don't know how to render it on a separate page. This also means that my CSS styling options are limited since I cannot design API data as I want without messing up my index page. If you have any sort of solution that is not way too complicated I would really appreciate your help.
Here is part of my code:
const input = document.getElementById(`location`);
const guests = document.getElementById(`guests`);
const check = document.querySelectorAll(".date");
let id;
document.getElementById(`submit`).addEventListener(`click`, function (e) {
e.preventDefault();
locationId();
});
async function locationId () {
let hotelId = input.value;
const options = {
method: 'GET',
headers: {
'X-RapidAPI-Key': '//API key goes here',
'X-RapidAPI-Host': 'tripadvisor16.p.rapidapi.com'
}
};
let response = await fetch(`https://tripadvisor16.p.rapidapi.com/api/v1/hotels/searchLocation?query=${hotelId}`, options);
if (!response.ok) throw new Error(`Woops something went wrong`);
let data = await response.json();
let geoId = await (data.data[0].geoId);
id= parseInt(geoId);
return (fetch(`https://tripadvisor16.p.rapidapi.com/api/v1/hotels/searchHotels?geoId=${id}&checkIn=${check[0].value}&checkOut=${check[1].value}&pageNumber=1&adults=${guests.value}currencyCode=USD`, options))
.then(response => response.json())
.then(data => {
let list = data.data.data;
displayObjectElements(list)
function displayObjectElements (object) {
let display = ``;
let price = ``;
object.forEach(element => {
display+= `<div class = "objectResults">
<ul class="hotel__lists">
<li><h2 class = "title">${element.title}</h2></li>
<li><img class= "hotels--photo "src="${element.cardPhotos[0].sizes.urlTemplate.split("?")[0] + `?w=500&h=500`}" alt=image--photo/></li>
<li><p>Ranking:${element.bubbleRating.rating}&#9734 out of 5&#9734</p></li>`
if(!element.priceForDisplay) {
display+= `<li><p>There is no price to display</p></li>`
display+= `<li><button class="booking-btn">Click to book</button></li>`
} else {
price =element.priceForDisplay.substring(1);
price= parseInt(price);
// console.log(price);
display+= `<li><p>Price: $${price} in total</p></li>`
display+= `<li><button class = "booking-btn">Click to book</button></li>
</ul>
</div>`
// console.log(display);
}});
document.body.innerHTML = display;
}
})
.catch(err => console.error(err));
}
I already tried with localStorage and sessionStorage but as a newbie I am just now sure how to put the whole API data in storage. Also, I desperately tried with window.location object as well but as I assumed that did nothing but open a new tab. Again, thanks in advance for any help!

Split a Javascript string by comma, but ignore commas that would be inside a string [duplicate]

My CSV data looks like this:
heading1,heading2,heading3,heading4,heading5
value1_1,value2_1,value3_1,value4_1,value5_1
value1_2,value2_2,value3_2,value4_2,value5_2
...
How do you read this data and convert to an array like this using JavaScript?:
[
heading1: value1_1,
heading2: value2_1,
heading3: value3_1,
heading4: value4_1
heading5: value5_1
],[
heading1: value1_2,
heading2: value2_2,
heading3: value3_2,
heading4: value4_2,
heading5: value5_2
]
....
I've tried this code but no luck!:
<script type="text/javascript">
var allText =[];
var allTextLines = [];
var Lines = [];
var txtFile = new XMLHttpRequest();
txtFile.open("GET", "file://d:/data.txt", true);
txtFile.onreadystatechange = function()
{
allText = txtFile.responseText;
allTextLines = allText.split(/\r\n|\n/);
};
document.write(allTextLines);
document.write(allText);
document.write(txtFile);
</script>
No need to write your own...
The jQuery-CSV library has a function called $.csv.toObjects(csv) that does the mapping automatically.
Note: The library is designed to handle any CSV data that is RFC 4180 compliant, including all of the nasty edge cases that most 'simple' solutions overlook.
Like #Blazemonger already stated, first you need to add line breaks to make the data valid CSV.
Using the following dataset:
heading1,heading2,heading3,heading4,heading5
value1_1,value2_1,value3_1,value4_1,value5_1
value1_2,value2_2,value3_2,value4_2,value5_2
Use the code:
var data = $.csv.toObjects(csv):
The output saved in 'data' will be:
[
{ heading1:"value1_1",heading2:"value2_1",heading3:"value3_1",heading4:"value4_1",heading5:"value5_1" }
{ heading1:"value1_2",heading2:"value2_2",heading3:"value3_2",heading4:"value4_2",heading5:"value5_2" }
]
Note: Technically, the way you wrote the key-value mapping is invalid JavaScript. The objects containing the key-value pairs should be wrapped in brackets.
If you want to try it out for yourself, I suggest you take a look at the Basic Usage Demonstration under the 'toObjects()' tab.
Disclaimer: I'm the original author of jQuery-CSV.
Update:
Edited to use the dataset that the op provided and included a link to the demo where the data can be tested for validity.
Update2:
Due to the shuttering of Google Code. jquery-csv has moved to GitHub
NOTE: I concocted this solution before I was reminded about all the "special cases" that can occur in a valid CSV file, like escaped quotes. I'm leaving my answer for those who want something quick and dirty, but I recommend Evan's answer for accuracy.
This code will work when your data.txt file is one long string of comma-separated entries, with no newlines:
data.txt:
heading1,heading2,heading3,heading4,heading5,value1_1,...,value5_2
javascript:
$(document).ready(function() {
$.ajax({
type: "GET",
url: "data.txt",
dataType: "text",
success: function(data) {processData(data);}
});
});
function processData(allText) {
var record_num = 5; // or however many elements there are in each row
var allTextLines = allText.split(/\r\n|\n/);
var entries = allTextLines[0].split(',');
var lines = [];
var headings = entries.splice(0,record_num);
while (entries.length>0) {
var tarr = [];
for (var j=0; j<record_num; j++) {
tarr.push(headings[j]+":"+entries.shift());
}
lines.push(tarr);
}
// alert(lines);
}
The following code will work on a "true" CSV file with linebreaks between each set of records:
data.txt:
heading1,heading2,heading3,heading4,heading5
value1_1,value2_1,value3_1,value4_1,value5_1
value1_2,value2_2,value3_2,value4_2,value5_2
javascript:
$(document).ready(function() {
$.ajax({
type: "GET",
url: "data.txt",
dataType: "text",
success: function(data) {processData(data);}
});
});
function processData(allText) {
var allTextLines = allText.split(/\r\n|\n/);
var headers = allTextLines[0].split(',');
var lines = [];
for (var i=1; i<allTextLines.length; i++) {
var data = allTextLines[i].split(',');
if (data.length == headers.length) {
var tarr = [];
for (var j=0; j<headers.length; j++) {
tarr.push(headers[j]+":"+data[j]);
}
lines.push(tarr);
}
}
// alert(lines);
}
http://jsfiddle.net/mblase75/dcqxr/
Don't split on commas -- it won't work for most CSV files, and this question has wayyyy too many views for the asker's kind of input data to apply to everyone. Parsing CSV is kind of scary since there's no truly official standard, and lots of delimited text writers don't consider edge cases.
This question is old, but I believe there's a better solution now that Papa Parse is available. It's a library I wrote, with help from contributors, that parses CSV text or files. It's the only JS library I know of that supports files gigabytes in size. It also handles malformed input gracefully.
1 GB file parsed in 1 minute:
(Update: With Papa Parse 4, the same file took only about 30 seconds in Firefox. Papa Parse 4 is now the fastest known CSV parser for the browser.)
Parsing text is very easy:
var data = Papa.parse(csvString);
Parsing files is also easy:
Papa.parse(file, {
complete: function(results) {
console.log(results);
}
});
Streaming files is similar (here's an example that streams a remote file):
Papa.parse("http://example.com/bigfoo.csv", {
download: true,
step: function(row) {
console.log("Row:", row.data);
},
complete: function() {
console.log("All done!");
}
});
If your web page locks up during parsing, Papa can use web workers to keep your web site reactive.
Papa can auto-detect delimiters and match values up with header columns, if a header row is present. It can also turn numeric values into actual number types. It appropriately parses line breaks and quotes and other weird situations, and even handles malformed input as robustly as possible. I've drawn on inspiration from existing libraries to make Papa, so props to other JS implementations.
I am using d3.js for parsing csv file. Very easy to use.
Here is the docs.
Steps:
npm install d3-request
Using Es6;
import { csv } from 'd3-request';
import url from 'path/to/data.csv';
csv(url, function(err, data) {
console.log(data);
})
Please see docs for more.
Update -
d3-request is deprecated. you can use d3-fetch
Here's a JavaScript function that parses CSV data, accounting for commas found inside quotes.
// Parse a CSV row, accounting for commas inside quotes
function parse(row){
var insideQuote = false,
entries = [],
entry = [];
row.split('').forEach(function (character) {
if(character === '"') {
insideQuote = !insideQuote;
} else {
if(character == "," && !insideQuote) {
entries.push(entry.join(''));
entry = [];
} else {
entry.push(character);
}
}
});
entries.push(entry.join(''));
return entries;
}
Example use of the function to parse a CSV file that looks like this:
"foo, the column",bar
2,3
"4, the value",5
into arrays:
// csv could contain the content read from a csv file
var csv = '"foo, the column",bar\n2,3\n"4, the value",5',
// Split the input into lines
lines = csv.split('\n'),
// Extract column names from the first line
columnNamesLine = lines[0],
columnNames = parse(columnNamesLine),
// Extract data from subsequent lines
dataLines = lines.slice(1),
data = dataLines.map(parse);
// Prints ["foo, the column","bar"]
console.log(JSON.stringify(columnNames));
// Prints [["2","3"],["4, the value","5"]]
console.log(JSON.stringify(data));
Here's how you can transform the data into objects, like D3's csv parser (which is a solid third party solution):
var dataObjects = data.map(function (arr) {
var dataObject = {};
columnNames.forEach(function(columnName, i){
dataObject[columnName] = arr[i];
});
return dataObject;
});
// Prints [{"foo":"2","bar":"3"},{"foo":"4","bar":"5"}]
console.log(JSON.stringify(dataObjects));
Here's a working fiddle of this code.
Enjoy! --Curran
You can use PapaParse to help.
https://www.papaparse.com/
Here is a CodePen.
https://codepen.io/sandro-wiggers/pen/VxrxNJ
Papa.parse(e, {
header:true,
before: function(file, inputElem){ console.log('Attempting to Parse...')},
error: function(err, file, inputElem, reason){ console.log(err); },
complete: function(results, file){ $.PAYLOAD = results; }
});
If you want to solve this without using Ajax, use the FileReader() Web API.
Example implementation:
Select .csv file
See output
function readSingleFile(e) {
var file = e.target.files[0];
if (!file) {
return;
}
var reader = new FileReader();
reader.onload = function(e) {
var contents = e.target.result;
displayContents(contents);
displayParsed(contents);
};
reader.readAsText(file);
}
function displayContents(contents) {
var element = document.getElementById('file-content');
element.textContent = contents;
}
function displayParsed(contents) {
const element = document.getElementById('file-parsed');
const json = contents.split(',');
element.textContent = JSON.stringify(json);
}
document.getElementById('file-input').addEventListener('change', readSingleFile, false);
<input type="file" id="file-input" />
<h3>Raw contents of the file:</h3>
<pre id="file-content">No data yet.</pre>
<h3>Parsed file contents:</h3>
<pre id="file-parsed">No data yet.</pre>
function CSVParse(csvFile)
{
this.rows = [];
var fieldRegEx = new RegExp('(?:\s*"((?:""|[^"])*)"\s*|\s*((?:""|[^",\r\n])*(?:""|[^"\s,\r\n]))?\s*)(,|[\r\n]+|$)', "g");
var row = [];
var currMatch = null;
while (currMatch = fieldRegEx.exec(this.csvFile))
{
row.push([currMatch[1], currMatch[2]].join('')); // concatenate with potential nulls
if (currMatch[3] != ',')
{
this.rows.push(row);
row = [];
}
if (currMatch[3].length == 0)
break;
}
}
I like to have the regex do as much as possible. This regex treats all items as either quoted or unquoted, followed by either a column delimiter, or a row delimiter. Or the end of text.
Which is why that last condition -- without it it would be an infinite loop since the pattern can match a zero length field (totally valid in csv). But since $ is a zero length assertion, it won't progress to a non match and end the loop.
And FYI, I had to make the second alternative exclude quotes surrounding the value; seems like it was executing before the first alternative on my javascript engine and considering the quotes as part of the unquoted value. I won't ask -- just got it to work.
Per the accepted answer,
I got this to work by changing the 1 to a 0 here:
for (var i=1; i<allTextLines.length; i++) {
changed to
for (var i=0; i<allTextLines.length; i++) {
It will compute the a file with one continuous line as having an allTextLines.length of 1. So if the loop starts at 1 and runs as long as it's less than 1, it never runs. Hence the blank alert box.
$(function() {
$("#upload").bind("click", function() {
var regex = /^([a-zA-Z0-9\s_\\.\-:])+(.csv|.xlsx)$/;
if (regex.test($("#fileUpload").val().toLowerCase())) {
if (typeof(FileReader) != "undefined") {
var reader = new FileReader();
reader.onload = function(e) {
var customers = new Array();
var rows = e.target.result.split("\r\n");
for (var i = 0; i < rows.length - 1; i++) {
var cells = rows[i].split(",");
if (cells[0] == "" || cells[0] == undefined) {
var s = customers[customers.length - 1];
s.Ord.push(cells[2]);
} else {
var dt = customers.find(x => x.Number === cells[0]);
if (dt == undefined) {
if (cells.length > 1) {
var customer = {};
customer.Number = cells[0];
customer.Name = cells[1];
customer.Ord = new Array();
customer.Ord.push(cells[2]);
customer.Point_ID = cells[3];
customer.Point_Name = cells[4];
customer.Point_Type = cells[5];
customer.Set_ORD = cells[6];
customers.push(customer);
}
} else {
var dtt = dt;
dtt.Ord.push(cells[2]);
}
}
}
Actually you can use a light-weight library called any-text.
install dependencies
npm i -D any-text
use custom command to read files
var reader = require('any-text');
reader.getText(`path-to-file`).then(function (data) {
console.log(data);
});
or use async-await :
var reader = require('any-text');
const chai = require('chai');
const expect = chai.expect;
describe('file reader checks', () => {
it('check csv file content', async () => {
expect(
await reader.getText(`${process.cwd()}/test/files/dummy.csv`)
).to.contains('Lorem ipsum');
});
});
This is an old question and in 2022 there are many ways to achieve this. First, I think D3 is one of the best alternatives for data manipulation. It's open sourced and free to use, but also it's modular so we can import just the fetch module.
Here is a basic example. We will use the legacy mode so I will import the entire D3 library. Now, let's call d3.csv function and it's done. This function internally calls the fetch method therefore, it can open dataURL, url, files, blob, and so on.
const fileInput = document.getElementById('csv')
const outElement = document.getElementById('out')
const previewCSVData = async dataurl => {
const d = await d3.csv(dataurl)
console.log({
d
})
outElement.textContent = d.columns
}
const readFile = e => {
const file = fileInput.files[0]
const reader = new FileReader()
reader.onload = () => {
const dataUrl = reader.result;
previewCSVData(dataUrl)
}
reader.readAsDataURL(file)
}
fileInput.onchange = readFile
<script type="text/javascript" src="https://unpkg.com/d3#7.6.1/dist/d3.min.js"></script>
<div>
<p>Select local CSV File:</p>
<input id="csv" type="file" accept=".csv">
</div>
<pre id="out"><p>File headers will appear here</p></pre>
If we don't want to use any library and we just want to use pain JavaScrip (Vanilla JS) and we managed to get the text content of a file as data and we don't want to use d3 we can implement a simple function that will split the data into a text array then we will extract the first line and split into a headers array and the rest of the text will be the lines we will process. After, we map each line and extract its values and create a row object from an array created from mapping each header to its correspondent value from values[index].
NOTE:
We also we going to use a little trick array objects in JavaScript can also have attributes. Yes so we will define an attribute rows.headers and assign the headers to it.
const data = `heading_1,heading_2,heading_3,heading_4,heading_5
value_1_1,value_2_1,value_3_1,value_4_1,value_5_1
value_1_2,value_2_2,value_3_2,value_4_2,value_5_2
value_1_3,value_2_3,value_3_3,value_4_3,value_5_3`
const csvParser = data => {
const text = data.split(/\r\n|\n/)
const [first, ...lines] = text
const headers = first.split(',')
const rows = []
rows.headers = headers
lines.map(line => {
const values = line.split(',')
const row = Object.fromEntries(headers.map((header, i) => [header, values[i]]))
rows.push(row)
})
return rows
}
const d = csvParser(data)
// Accessing to the theaders attribute
const headers = d.headers
console.log({headers})
console.log({d})
Finally, let's implement a vanilla JS file loader using fetch and parsing the csv file.
const fetchFile = async dataURL => {
return await fetch(dataURL).then(response => response.text())
}
const csvParser = data => {
const text = data.split(/\r\n|\n/)
const [first, ...lines] = text
const headers = first.split(',')
const rows = []
rows.headers = headers
lines.map(line => {
const values = line.split(',')
const row = Object.fromEntries(headers.map((header, i) => [header, values[i]]))
rows.push(row)
})
return rows
}
const fileInput = document.getElementById('csv')
const outElement = document.getElementById('out')
const previewCSVData = async dataURL => {
const data = await fetchFile(dataURL)
const d = csvParser(data)
console.log({ d })
outElement.textContent = d.headers
}
const readFile = e => {
const file = fileInput.files[0]
const reader = new FileReader()
reader.onload = () => {
const dataURL = reader.result;
previewCSVData(dataURL)
}
reader.readAsDataURL(file)
}
fileInput.onchange = readFile
<script type="text/javascript" src="https://unpkg.com/d3#7.6.1/dist/d3.min.js"></script>
<div>
<p>Select local CSV File:</p>
<input id="csv" type="file" accept=".csv">
</div>
<pre id="out"><p>File contents will appear here</p></pre>
I used this file to test it
Here is another way to read an external CSV into Javascript (using jQuery).
It's a little bit more long winded, but I feel by reading the data into arrays you can exactly follow the process and makes for easy troubleshooting.
Might help someone else.
The data file example:
Time,data1,data2,data2
08/11/2015 07:30:16,602,0.009,321
And here is the code:
$(document).ready(function() {
// AJAX in the data file
$.ajax({
type: "GET",
url: "data.csv",
dataType: "text",
success: function(data) {processData(data);}
});
// Let's process the data from the data file
function processData(data) {
var lines = data.split(/\r\n|\n/);
//Set up the data arrays
var time = [];
var data1 = [];
var data2 = [];
var data3 = [];
var headings = lines[0].split(','); // Splice up the first row to get the headings
for (var j=1; j<lines.length; j++) {
var values = lines[j].split(','); // Split up the comma seperated values
// We read the key,1st, 2nd and 3rd rows
time.push(values[0]); // Read in as string
// Recommended to read in as float, since we'll be doing some operations on this later.
data1.push(parseFloat(values[1]));
data2.push(parseFloat(values[2]));
data3.push(parseFloat(values[3]));
}
// For display
var x= 0;
console.log(headings[0]+" : "+time[x]+headings[1]+" : "+data1[x]+headings[2]+" : "+data2[x]+headings[4]+" : "+data2[x]);
}
})
Hope this helps someone in the future!
A bit late but I hope it helps someone.
Some time ago even I faced a problem where the string data contained \n in between and while reading the file it used to read as different lines.
Eg.
"Harry\nPotter","21","Gryffindor"
While-Reading:
Harry
Potter,21,Gryffindor
I had used a library csvtojson in my angular project to solve this problem.
You can read the CSV file as a string using the following code and then pass that string to the csvtojson library and it will give you a list of JSON.
Sample Code:
const csv = require('csvtojson');
if (files && files.length > 0) {
const file: File = files.item(0);
const reader: FileReader = new FileReader();
reader.readAsText(file);
reader.onload = (e) => {
const csvs: string = reader.result as string;
csv({
output: "json",
noheader: false
}).fromString(csvs)
.preFileLine((fileLine, idx) => {
//Convert csv header row to lowercase before parse csv file to json
if (idx === 0) { return fileLine.toLowerCase() }
return fileLine;
})
.then((result) => {
// list of json in result
});
}
}
I use the jquery-csv to do this.
and I provide two examples as below
async function ReadFile(file) {
return await file.text()
}
function removeExtraSpace(stringData) {
stringData = stringData.replace(/,( *)/gm, ",") // remove extra space
stringData = stringData.replace(/^ *| *$/gm, "") // remove space on the beginning and end.
return stringData
}
function simpleTest() {
let data = `Name, Age, msg
foo, 25, hello world
bar, 18, "!! 🐬 !!"
`
data = removeExtraSpace(data)
console.log(data)
const options = {
separator: ",", // default "," . (You may want to Tab "\t" or somethings.
delimiter: '"', // default "
headers: true // default true
}
// const myObj = $.csv.toObjects(data, options)
const myObj = $.csv.toObjects(data) // If you want to use default options, then you can omit them.
console.log(myObj)
}
window.onload = () => {
const inputFile = document.getElementById("uploadFile")
inputFile.onchange = () => {
const inputValue = inputFile.value
if (inputValue === "") {
return
}
const selectedFile = document.getElementById('uploadFile').files[0]
const promise = new Promise(resolve => {
const fileContent = ReadFile(selectedFile)
resolve(fileContent)
})
promise.then(fileContent => {
// Use promise to wait for the file reading to finish.
console.log(fileContent)
fileContent = removeExtraSpace(fileContent)
const myObj = $.csv.toObjects(fileContent)
console.log(myObj)
})
}
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-csv/1.0.11/jquery.csv.min.js"></script>
<label for="uploadFile">Demo 1</label>
<input type="file" id="uploadFile" accept=".csv"/>
<button onclick="simpleTest()">Demo 2</button>
With this function csvToObjs you can transform data-entries from format CSV to an array of objects.
function csvToObjs(string) {
const lines = data.split(/\r\n|\n/);
let [headings, ...entries] = lines;
headings = headings.split(',');
const objs = [];
entries.map(entry=>{
obj = entry.split(',');
objs.push(Object.fromEntries(headings.map((head, i)=>[head, obj[i]])));
})
return objs;
}
data = `heading1,heading2,heading3,heading4,heading5
value1_1,value2_1,value3_1,value4_1,value5_1
value1_2,value2_2,value3_2,value4_2,value5_2`
console.log(csvToObjs(data));

Saving fetch() data to array variable to use in another outside function(s)

So, I am trying to grab the data from the GET fetch that I used.
const BASE_URL = "http://localhost:3000/quotes"
document.addEventListener('DOMContentLoaded', function() {
randomButton();
createButton();
loadQuotes();
});
const loadQuotes = function() {
fetch(BASE_URL)
.then(res => res.json())
.then(results => {
results.data.forEach(json => json.attributes.sentence)
});
}
function addQuote(quote) {
let ul = document.querySelector('#quote-display');
let li = document.createElement('li');
li.innerText = quote;
ul.appendChild(li);
}
When I wrap a console.log around json.attributes.sentence or use the addQuote(json.attributes.sentence) function like so. I definitely get the out put in the console.log/in the ul/li tags. I also ran a typeof on the json.attributes.sentence and it shows it's outputting strings.
However, I would like to add that data to an array to access later from other methods.
I tried creating a global variable that was an empty array and push the json data attribute strings to the array but didn't work. Ideas?
Thanks in advance.
btw the JSON looks like this
{
data: [
{
id: "1",
type: "quote",
attributes: {
sentence: "Here's looking at you, kid."
}
}
]
}

How to add item to local storage

I am creating a song book app with 'add to favorite' button. i have song1.html song2.html and favorite.html.
in song1.html, when add to favorite button is clicked. i am storing the link to that song in local storage.
This is my song1.html
<!DOCTYPE html>
<html>
<body>
<button onclick="mySongOne()">add to favorite</button>
<script>
function mySongOne() {
localStorage.setItem("favsong", "<a href='https://www.song1.com'><h1>song1</h1></a>");
}
</script>
</body>
</html>
in song2.html, when add to favorite button is clicked. i am storing the link of the second song in local storage.
song2.html
<!DOCTYPE html>
<html>
<body>
<button onclick="mySongTwo()">add to favorite</button>
<script>
function mySongTwo() {
localStorage.setItem("favsong", "<a href='https://song2.com'><h1>song2</h1></a>");
}
</script>
</body>
</html>
now i have a favorite.html for listing my favourite songs. and favourite.html will retrieve the links that i stored in local storage.
favorite.html
<!DOCTYPE html>
<html>
<body onload="myFunction()">
<div id="result"></div>
<script>
function myFunction() {
document.getElementById("result").innerHTML = localStorage.getItem("favsong");
}
</script>
</body>
</html>
Now i want to show both song 1 and song 2 in favorite.html.
but only song 2 is displayed in favourite.html. How to accomplish this.
Store list in javascript Array.
You need to either use different keys or store multiple strings in array and then JSON.stringify that to save in localStorage.
Similary when you get the same string from localStorage then convert it into object using JSON.parse.
<!DOCTYPE html>
<html>
<body>
<div id="result"></div>
<script>
// Check browser support
if (typeof(Storage) !== "undefined") {
// Store
let list = [];
list.push("<h1>John<h1>");
list.push("<h2>David<h2>");
localStorage.setItem("list", JSON.stringify(list));
// Retrieve
document.getElementById("result").innerHTML = JSON.parse(localStorage.getItem("list"));
} else {
document.getElementById("result").innerHTML = "Sorry, your browser does not support Web Storage...";
}
</script>
</body>
</html>
When using localStorage, you can only have one item per key. localStorage allows you to store string-data as the value, thus we can use JSON.
You can serialize an array of items you want to add and then append them to the key inside of localStorage.
References:
JSON.stringify()
JSON.parse()
localStorage
JSFiddle. StackOverflow doesn't allow localStorage so I hosted my code there.
Code:
let items = ['<h1>John<h1>', '<h2>David<h2>', '<h3>Mary<h3>', '<h4>Bob<h4>'];
// Stringify the array and store it
localStorage.setItem("list", JSON.stringify(items));
// Parse the stringified array back from localStorage
let itemsRetrieved = JSON.parse(localStorage.getItem('list'));
// Get div with .list class
let div = document.querySelector('.list');
// Iterate retrieved array and append items
itemsRetrieved.forEach(item => {
div.innerHTML += item;
});
// Add an item
itemsRetrieved.push('<span style="color: red;">Dylan</span>');
// Stringify the new array and overwrite the key
localStorage.setItem("list", JSON.stringify(itemsRetrieved));
Code [For those who love encapsulation]:
let items = ['<h1>John<h1>', '<h2>David<h2>', '<h3>Mary<h3>', '<h4>Bob<h4>'];
// Stringify the array and store it [Initial]
localStorage.setItem("list", JSON.stringify(items));
// Returns parsed array
function getData(key) {
return JSON.parse(localStorage.getItem(key));
}
// Returns new array
function addData(key, item) {
// Get current array
let currentData = getData(key);
// Add an item
currentData.push(item);
// Stringify the new array and overwrite the key
localStorage.setItem(key, JSON.stringify(currentData));
return currentData;
}
// Parse the stringified array back from localStorage
let itemsRetrieved = getData('list');
// Get div with .list class
let div = document.querySelector('.list');
// Add an item
itemsRetrieved = addData('list', '<span style="color: red;">Dylan</span>');
// Iterate retrieved array and append items
itemsRetrieved.forEach(item => {
div.innerHTML += item;
});
If you really need to append data to the same LocalStorage key, there is no built-in append function.
However, you can use a custom function, for instance the one proposed in this answer: https://stackoverflow.com/a/7680123/2446264, and get the following code to do what you want:
<!DOCTYPE html>
<html>
<body>
<div id="result"></div>
<script>
// Check browser support
if (typeof(Storage) !== "undefined") {
// Store
localStorage.setItem("list", "<h1>John<h1>");
appendToStorage("list", "<h2>David<h2>");
// Retrieve
document.getElementById("result").innerHTML = localStorage.getItem("list");
} else {
document.getElementById("result").innerHTML = "Sorry, your browser does not support Web Storage...";
}
function appendToStorage(name, data){
var old = localStorage.getItem(name);
if(old === null) old = "";
localStorage.setItem(name, old + data);
}
</script>
</body>
</html>
Basically, you'll need to store those data as a list of strings (or use different keys 'list1', 'list2' etc...).
So, when you are putting your value into the local storage initially, you'll need to do something like this:
var initialValue = ['<h1>John<h1>']; // array of strings
// since Local Storage accepts only string values,
// you can store an array or any other object by using JSON.stringify function
localStorage.setItem('list', JSON.stringify(initialValue);
// updating local storage
var list = JSON.parse(localStorage.getItem('list');
list.push('<h2>David<h2>');
localStorage.setItem('list', JSON.stringify(list));
Then you can append those value by looping through the list.
var output = '';
for (var i = 0; i < list.length; i++) {
output = output + list[i];
}
document.getElementById("result").innerHTML = output;
What you are doing wrong:
localstorage doesn't store data types, but rather stores a string.
For instance, if you was to store an integer in a localstorage property, the data type would always be returned as a string.
Since you are attempting to store an array of values, you will need to create a CSV (comma-separated values) method.
var strLocalStorage = "John, Peter, Fred, Paul, Mary, Elizabeth";
You can the parse this into local storage using one of two methods
JSON (See example beneath)
SPLIT (variable.split(", ");
It is important you should be aware, Browsers set limitations of 5MB of data allocated between LocalStorage and SessionStorage.
This can cause problems when a large amount of data needs to be stored, in the event of your edited example, storing various URLs
What may be an alternative to your solution, would be to create CSV of favourite songs using your SQL Table's unique ID for the song table entry.
However, in the event your code is only using Front End languages such as HTML and JAVASCRIPT, then you may prefer to use IndexedDB
How to use Indexed DBs
This will allow you to create a local database that is accessible offline and allows you to recall and edit the values easier such as
LocalStorage Example:
var blLocalStorage = false;
function funInitiate(){
if (typeof(Storage) !== "undefined") {
console.log("localstorage detected on this browser");
blLocalStorage = true;
}else{
console.log("local storage is not supported by this browser, please update");
}
}
function funTestLocalStorage(){
var strLocalStorage = localStorage.getItem("FavSongs");
if(strLocalStorage === null){
return false;
}else{
return true;
}
}
function funGetSongFavorites(){
if(blLocalStorage){
if (funTestLocalStorage()){
var arrLocalStorage = JSON.parse(localStorage.getItem("FavSongs"));
var elOutput = document.querySelector("#result");
for(i = 0; i < arrLocalStorage.length; i++){
elOutput.innerHTML += "<br>" + arrLocalStorage[i]
}
}
}else{
console.log("No local storage - function funGetSongFavourites aborted");
}
}
function funAddFav(strURL){
if(blLocalStorage){
var strLocalStorage = localStorage.getItem(strURL);
if(strLocalStorage === null){
localStorage.setItem("FavSongs", strURL);
}else{
var arrList = JSON.parse(localStorage.getItem('FavSongs'));
arrList.push(strURL);
}
localStorage.setItem('FavSong', JSON.stringify(arrList));
console.log("Favourite Lists update: " + strURL);
}else{
console.log("No local storage - Function funAddFav aborted");
}
}
document.addEventListener("DOMContentLoaded", funInitiate, false);
<!DOCTYPE html>
<html>
<head>
<title>Webpage Title</title>
<script src="pathToJSScriptShownBeneath"></script>
</head>
<body>
<button onclick="funAddFav('http://youtube.com')">
Add to favorite
</button>
<div id="result"></div>
</body>
</html>
Indexed DB example
var songList = [
{ id: 1, artist: "2pac", title: "Dear Mama", URL: "https://www.youtube.com/watch?v=Mb1ZvUDvLDY" },
{ id: 2, artist: "Biggie Smalls", title: "Hypnotize", URL: "https://www.youtube.com/watch?v=glEiPXAYE-U" }
];
const dbName = "favSongs";
var request = indexedDB.open(dbName, songList.length);
request.onerror = function(event) {
console.log("An Error has occured, script will now exist";
return;
};
request.onupgradeneeded = function(event) {
var db = event.target.result;
var objectStore = db.createObjectStore("SongList", { keyPath: "id" });
// There can be multiple songs by 1 artist or band therefore this will
// declare this as a false unique entry, the sample applies for song titles
// some songs have the same title but performed by different artists.
objectStore.createIndex("artist", "artist", { unique: false });
objectStore.createIndex("title", "title", { unique: false });
// Song URLs will be unique, so we set this as a individually unique
objectStore.createIndex("URL", "URL", { unique: true });
// Use transaction oncomplete to make sure the objectStore creation is
// finished before adding data into it.
objectStore.transaction.oncomplete = function(event) {
// Store values in the newly created objectStore.
var customerObjectStore = db.transaction("favSongs", "readwrite").objectStore("SongList");
customerData.forEach(function(songList) {
customerObjectStore.add(songList);
});
};
};
// Retrieving Data:
var transaction = db.transaction(["favSongs"]);
var objectStore = transaction.objectStore("SongList");
var request = objectStore.get(2);
request.onerror = function(event) {
console.log("Entry doesnt exist of has been deleted");
};
request.onsuccess = function(event) {
var strArtist = request.result.artist;
var strTitle = request.result.title;
var strURL = request.result.URL;
};
// Deleting Data
var request = db.transaction(["favSongs"], "readwrite")
.objectStore("SongList")
.delete(1);
request.onsuccess = function(event) {
console.log ("Entry 1 has been deleted");
};
Add item: localStorage.name = 'Name'
Get item: let name = localStorage.name
Remove item: localStorage.removeItem('name')

Trying to parse a JSON file from a URL

This is the json I am using: json
I want to be able to pull different data out of it and display it on a webpage. Particularly the badge name and related info. The badges array is giving me trouble.
I have taken a look at the jquery documentation here: http://api.jquery.com/jquery.getjson/
but they kind of lost me because it doesn't match what I am trying to do.
Here is the js file I tried with no luck... Thanks
`
//Function to print message to console
function printMessage(badgeCount, points, arr) {
const message = `Anthony Scott has ${badgeCount} total badge(s) and ${points} points in JavaScript. here is a list of badges ${arr}`;
document.write(message);
}
(function() {
$.getJSON("https://teamtreehouse.com/anthonyscott4.json", {})
.done(function(data) {
// Parse the data
const profile = JSON.parse(data);
// Print the data
let arr = [];
for(var x in profile.badges) {
arr.push(profile.badges[x].name)
}
document.write(profile.badges.length, profile.points.JavaScript, arr);
});
});
`
Since you are using $.getJSON the JSON is already parsed for you in the callback, so there is no need to call JSON.parse on the result.
for in loops are used to iterate over an objects properties. What you are looking for is a normal for loop or forEach
var request = $.getJSON('https://teamtreehouse.com/anthonyscott4.json');
request.done(function (response) {
var badges = [];
response.badges.forEach(function (badge) {
badges.push(badge.name);
});
$('#result').append(badges.toString());
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="result"></div>
Example with for loop:
var request = $.getJSON('https://teamtreehouse.com/anthonyscott4.json');
request.done(function (response) {
var badges = [];
for (var i = 0; i < response.badges.length; ++i) {
var badge = response.badges[i];
badges.push(badge.name);
}
$('#result').append(badges.toString());
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="result"></div>

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