I have built a todo list using Vanilla Javascript and localstorage. The todo list has the following key, value:
key: todolist
value: [[\"id:0\",\"title:buy groceries\",\"done:false\"],
[\"id:1\",\"title:pick up dry cleaning\",\"done:false\"],
[\"id:2\",\"title:walk dog\",\"done:false\"]]
The values display just great on my website (only the title is displaying) but when I refresh the page, the whole object is displaying.
Before page refresh:
buy groceries
pick up dry cleaning
walk dog
After page refresh:
id:0,title:buy groceries,done:false
id:1,title:pick up dry cleaning,done:false
id:2,title:walk dog,done:false
Obviously, after a page refresh I only want the title to display on the list inside the li tag. It's a head scratcher because it only does this after a page refresh.
How do I get only the title to display after page refresh?
I'm somewhat of a newbie to Javascript and can't quite figure out how to make this happen. I've been Googling for almost two days and ready to tear my hair out!!
// set up some variables for elements on the page
const form = document.querySelector('form');
const ul = document.querySelector('ul');
const button = document.querySelector('button');
const input = document.getElementById('item');
// Fix empty array when script runs by making a conditional statement that
checks if localStorage already exists
//let itemsArray = localStorage.getItem('todolist') ?
JSON.parse(localStorage.getItem('todolist')) : [];
let todolist;
if (localStorage.getItem('todolist')) {
itemsArray = JSON.parse(localStorage.getItem('todolist'));
} else {
itemsArray = [];
}
localStorage.setItem('todolist', JSON.stringify(itemsArray));
const data = JSON.parse(localStorage.getItem('todolist'));
//alert(typeof(data));
// function that creates an li element, sets the text of the element to the
parameter, and appends the list item to the ul.
const liMaker = (text) => {
const li = document.createElement('li');
li.textContent = text;
ul.appendChild(li);
// Create a "close" button and append it to each list item
var span = document.createElement("SPAN");
var txt = document.createTextNode("🗑️");
span.className = "close";
span.appendChild(txt);
li.appendChild(span);
for (i = 0; i < close.length; i++) {
close[i].onclick = function() {
var div = this.parentElement;
div.style.display = "none";
}
}
}
// Event listener that submits the value of the input
form.addEventListener('submit', function (e) {
e.preventDefault();
var id = "id:" + itemsArray.length;
var title = "title:" + input.value;
var done = "done:" + "false";
itemsArray.push([id, title, done]);
//itemsArray.push(input.value);
localStorage.setItem('todolist', JSON.stringify(itemsArray));
liMaker(input.value);
input.value = "";
});
data.forEach(item => {
liMaker(item);
});
// clear items from todolist
button.addEventListener('click', function () {
localStorage.removeItem("todolist");
while (ul.firstChild) {
ul.removeChild(ul.firstChild);
}
itemsArray = [];
});
One thing I should note, the page refresh issue doesn't happen when I change the following:
itemsArray.push([id, title, done]);
to the following:
itemsArray.push(input.value);
The main reason you are having this problem is because your JSON is not formatted properly.
The reason you are only seeing the problem on page refresh is because at this point local storage contains the "todolist" key with your improperly formed JSON. This JSON value is then stored in your data variable and output to your list items in an undesired way (as you described).
Otherwise (without page refresh) the text of your list items is coming directly from the text in the input field.
If you make the following changes to your code it will work properly (I have tested it). Hope it helps.
JavaScript comments
Firstly i'm not sure if this just happened when you posted your code here but if your comments in JS extend across two lines or more then you need to put // on all lines.
For example in your code you have:
//function that creates an li element, sets the text of the element to the
parameter, and appends the list item to the ul.
and it should be:
//function that creates an li element, sets the text of the element to the
//parameter, and appends the list item to the ul.
The format of your JSON
Secondly I see a problem with the way the JSON is formatted.
It should look something like the following (before slashes are added).
[{"id":0,"title":"buy groceries","done":false},
{"id":1,"title":"pick up dry cleaning","done":false},
{"id":2,"title":"walk dog","done":false}]
Note each property name (i.e "id", "title" and "done") should have double quotes and each property value (e.g "buy groceries") should have double quotes (unless its an int or a boolean etc).
You can use a tool called JSLint to check your JSON is valid.
So in order to create your JSON in the right format (when the form is submitted)
change these lines of code:
var id = "id:" + itemsArray.length;
var title = "title:" + input.value;
var done = "done:" + "false";
itemsArray.push([id, title, done]);
to the following:
var idValue = itemsArray.length;
var titleValue = input.value;
var doneValue = false;
itemsArray.push({"id": idValue, "title": titleValue, "done" : doneValue});
Iterating through the array
Your data variable will contain the array of todolist objects (from local storage).
So therefore the item you have in the following code will contain the full object i.e {"id":0,"title":"buy groceries","done":false}.
So in order to get the title here you need to say item.title. (This will work now that the JSON will be properly formatted):
data.forEach(item => {
//log the item to check it.
console.log(item);
liMaker(item.title);
});
Related
I'm new to coding, and I need to display past search values from an input field using localstorage. The only way I can think of is by using one object key with an array of stored values from an on click event. Problem is, I can only get one position to appear as a value, with each value generated replacing the last. I've tried for loops and can't seem to get it to work. This is the code I have so far:
$('.search-city').on('click', function(e){
e.preventDefault();
var textArr = [];
var text = $(".form-control").val();
textArr.push(text);
localStorage.setItem("value1", textArr);
});
$('.search-city').on('click', function(e){
e.preventDefault();
var search = localStorage.getItem("value1")
This would work:
$('.search-city').on('click', function(e){
e.preventDefault();
// get the value from local storage
var localValue = localStorage.getItem('value1');
// if we had a value, parse it back to an array, if we dont, create an empty array
var textArr = localValue ? JSON.parse(localValue) : [];
// get the text from the search input, dont use "form-control"
// you're likely to have several of those on the page
// give the element a custom class like "search-input" and use that (id would be even better)
var text = $('.search-input').val();
// add the text to the array
text = trim(text);
if (text) {
textArr.push(text);
}
// enforce a size limit here by removing the 0 index item if the count has grown too large
var maxAllowed = 10;
while (textArr.length > maxAllowed) {
textArr.shift();
}
// localstorage can only hold simple strings so we'll JSON stringify our object and store that
localValue = JSON.stringify(textArr);
localStorage.setItem("value1", localValue);
});
I'm trying to load an array from one page and then have the results appear on another using javascript/jQuery. So a user will make a selection from a dropdown. Based on this dropdown the "customers" address, phone, email, etc. will appear in a text field. I'm trying to store those results in to the array (name | address | etc in one index of the array), display the result on the second screen, and then allow the user to add more names if necessary.
At the moment I'm trying to use localStorage to store the values and then JSON.stringify to convert the results so they can be stored in the array.
I think these are all of the pertinent lines:
var customerArray = [];
var getName = $('#DropDownList1').val();
var getAddress = $('#DataList1').text().trim();
var getPhone = $('#DataList2').text().trim();
var getEmail = $('#DataList3').text().trim();
//store the variables
localStorage.setItem("name", getName);
localStorage.setItem("address", getAddress);
localStorage.setItem("phone", getPhone);
localStorage.setItem("email", getEmail);
//user will click #btnAdd to add the customers information
//into customerArray[]
$("#btnAdd").click(function () {
var setName = localStorage.getItem("name");
var setAddress = localStorage.getItem("address");
var setPhone = localStorage.getItem("phone");
var setEmail = localStorage.getItem("email");
var post = setName + setAddress + setPhone + setEmail;
if (customerArray.length == 0) {
customerArray[0] = post;
} else {
for (var i = 1; i < customerArray.length; ++i) {
//store results of 'post' into the array
customerArray.push(post);
localStorage.setItem("storedArray",JSON.stringify(customerArray));
}
}
}); //end #btnAdd click event
Form here the 2nd page will load with a text field that will (should) display the results of the array (customerArray). Unfortunately I can only get 1 value to appear.
At the moment this is the block being used to display the results:
$('#tbContactList').val(JSON.parse(localStorage.getItem("storedArray")));
If it matters I'm writing the application using Visual Studio Express 2012 for Web. The data that initially populates the customers information comes from a database that I've used ASP controls to get. I'm confident there is a perfectly simple solution using ASP/C# but I'm trying to solve this problem using javascript/jQuery - I'm more familiar with those languages than I am with C#.
Thank you.
Use Array.join() to turn your array into a string to store.
Then use Array.split() to turn your string back into an Array.
Example
var arr=['name','email','other'];
var localStorageString=arr.join(',');
localStorage.setItem('info',localStorageString);
var reassemble=localStorage.info.split(',');
for(var i=0;i<reassemble.length;i++){
document.body.innerHTML+=reassemble[i]+"<br/>";
}
http://jsfiddle.net/s5onLxd3/
Why does the user have to leave the current page though? IS a tabbed/dynamic interface not an option?
Ok so here is what I'm trying to do. I have an XML file that contains 1000 classified Ad's for my employer and he is wanting to be able to have each ad show up one item at a time. I have the XML file loaded and can get it to post the first Ad but I have no idea how to get it to go to the next item in the loop or to go backwards which is were I am having the trouble. Here is the code for trying to go forward.
var x=xmlDoc.getElementsByTagName("item");
for (i=0;i<x.length;i++) {
x= x[i].getElementsByTagName("description")[0].childNodes[0].nodeValue;
break;
}
document.getElementById("classified").innerHTML =x;
function forward() {
var text ="";
var x=xmlDoc.getElementsByTagName("item");
for (i=0;i<x.length;i++) {
x= x[i].getElementsByTagName("description")[0].childNodes[0].nodeValue;
continue;
}
document.getElementById("classified").innerHTML = x;
}
So what I'm trying to get to happen is with a button click I can get the next ad to post and remove the first one presented with the forward button and get the backwards button to do the exact opposite
You can store all your ad's descriptions in array and remember current index (the one was shown). Demo.
Sample code. I'm assuming you have two buttons with ids back/forward somewhere on your page.
var fakeAds = Array.apply(null, new Array(1000)).map(function(_, i){
return 'some random text ' + (i+1);
}), //replace with actual data
idx = 0, //current index
display = document.getElementById('display'), //where to show
total = fakeAds.length; //total number of ads
function show() { //actually show ad at current idx.
display.innerHTML = fakeAds[idx];
}
document.getElementById('back').addEventListener('click', function(){
--idx < 0 && (idx = total - 1); //decrement index and show
show();
});
document.getElementById('forward').addEventListener('click', function(){
idx = ++idx%total; //increment index and show
show();
});
show(); //do show starting index.
Here are the two functions you need : DEMO
From your code, this is how to extract at first all the item from your XML file, and then via the loop you get each description from them. This will generate a list stored in your x var.
This creates a list of all item elements in your XML file (this is the full method below)
var connectXMLFile = new XMLHttpRequest();
Define which file to open and send the request
connectXmlFile.open("GET","PathToYourXMLFile.xml", false);
connectXMLFile.setRequestHeader("Content-Type", "text/xml");
connectXMLFile.send(null);
Get the response and all item elements
var xmlDoc = connectXMLFile.responseXML;
var x=xmlDoc.getElementsByTagName("item");
Represents the list of ads you got
var adsList = [];
Then loop to get each description and add it to the list
for (var i=0;i<x.length;i++) {
adsList.push(x[i].getElementsByTagName("description")[0].childNodes[0].nodeValue);
}
Represents the current ad showed
var adNumber = 0;
function forward() {
if (adNumber >= adsList.length) adNumber = 0;
document.getElementById("ad").innerHTML = adsList[adNumber];
adNumber++;
}
function backwards() {
if (adNumber == 0) adNumber = adsList.length;
document.getElementById("ad").innerHTML = adsList[adNumber - 1];
adNumber--;
}
This is based on the code you provided, if you need any explanation feel free to ask.
I am trying to do the folowing with Asp.net 3.5/IIS
A web form with a top level repeatable form. So basically a Order->Products->ProductsParts kinda of scenerio. Order is only one. Product is repeatable. Each product has repeatable products parts. The product and product part have a whole bunch of fields so I cannot use a grid.
So, I have add/remove buttons for Product and within each product add/remove buttons for each product part.
That is my requirement. I have been able to achieve add/remove after some research using jquery/js. How, do i capture this data on the server? Since javascript is adding and removing these controls they are not server side and I don't know how to assign name attributes correctly. I am trying following javascript but it ain't working:
function onAddProperty(btnObject){
var previous = btnObject.prev('div');
var propertyCount = jquery.data(document.body, 'propertyCount');
var newDiv = previous.clone(true).find("*[name]").andSelf().each(function () { $(this).attr("name").replace(($(this).attr("name").match(/\[[0-9]+\]/), cntr)); }); ;
propertyCount++;
jquery.data(document.body, 'propertyCount', propertyCount);
//keep only one unit and remove rest
var children = newDiv.find('#pnlUnits > #pnlUnitRepeater');
var unitCount = children.length;
var first = children.first();
for (i = 1; i < unitCount; i++) {
children[i].remove();
}
newDiv.id = "pnlPropertySlider_" + propertyCount;
newDiv.insertBefore(btnObject);
}
I need to assign name property as array so that I can read it in Request.Form
Fix for not updating ids not working:
var newDiv = previous.clone(true).find("input,select").each(function () {
$(this).attr({
'name': function () {
var name = $(this).attr('name');
if (!name) return '';
return name.replace(/property\[[0-9]+\]/, 'property' + propertyCount);
}
});
}).end().insertBefore(btnObject);
The issue looks like the following line:
$(this).attr("name").replace(($(this).attr("name").match(/\[[0-9]+\]/), cntr));
This statement doesn't do anything. Strings in JavaScript an immutable, and .replace only returns the string with something replaced.
You would then have to actually set the attr("name") to the new string that has the replaced value:
http://api.jquery.com/attr/
I can't help much more without seeing your HTML.
Alright.
I have created a custom object that I am using to build a list of things. One of the functions for this custom object involves adding the object to a list. In this list, there is a value I assign to each different element that keeps track of how many of that item have been added to the list. Such as:
(3) Object#1
(2) Object#2
3 and 2 of course being the 'count' value of that object. My problem is that I am creating the list dynamically by calling:
function Thing(count, value)
{
this.count=count;
this.value=value;
}
Thing.prototype.addToList = function()
{
if (this.count == 0)
{
this.count++;
var list = document.getElementById("blah");
var li = document.createElement("li");
var interior = "<span id='counter'>("+this.count+")</span>";
li.innerHTML = interior;
list.appendChild(li);
}
else
{
this.count++;
var countInc = document.getElementById("counter");
countInc.innerHTML = "("+this.count+")";
}
}
This works fine, but if I am to add multiple Objects with separate count values, there is no way to distinguish between them, and as a result, the first 'counter' span in the list is altered with the the count value of the most recently added object. All other count values remain the same (1). I have tried:
var interior = "<span id='counter"+this.value+"'>("+this.count+")</span>";
To try and create a unique id each time, but this isn't working. Basically, I am wondering how I can create new ID values each time I instantiate a new Object.
try this
var list = document.getElementById("blah");
var li = document.createElement("li");
var interior = "<span id='counter-"+this.count+"'>("+this.count+")</span>";
li.innerHTML = interior;