I've been playing around with http://almende.github.com/chap-links-library/timeline.html which allows the user to add/edit/delete events on the timeline. Closing or refreshing the browser resets it to the pre-loaded data source - JSON, table info or Google Spreadsheet. Nothing the user adds or changes is saved.
How do you make user changes persistent?
I've used HTML5 localStorage before for saving text, checkbox, and select box entries, etc. but with this Timeline the only entry is:
div id="mytimeline"
which has a script associated with it:
// Instantiate our timeline object.
timeline = new links.Timeline(document.getElementById('mytimeline'));
which is the reference to the JS that builds the timeline container.
Any ideas or examples or pointers?
Thanks.
Update:
Here is what I have so far:
//Check to see if localStorage is supported
var db = getLocalStorage() || alert("Local Storage Not supported in this browser. Try updating to the latest Firefox, Chrome or Safari browsers.");
function getLocalStorage() {
try {
if(window.localStorage ) return window.localStorage;
}
catch (e)
{
return undefined;
}
}
//Store Timeline Data to localStorage
function storeTimelineData(){
var data=timeline.getData();
localStorage.setItem('mytimeline', JSON.stringify(data));
var storedData=JSON.parse( localStorage.getItem('myTimeline') );
// clear storage
function clearLocal() {
clear: localStorage.clear();
return false;
}
I've also made these changes - body onload="storedData()" to try to load localStorage saved values and changed div id="mytimeline" onmouseup="storeTimelineData()" to store the values when changes are made to the timeline.
Changes to the Timeline are being saved in localStorage and I can see these changes in the console for Key/Values. When I refresh the browser though, these are not being loaded into mytimeline. What did I miss?
Thanks.
I've never seen plugin until your post but in the API docs are all sorts of methods. The most important one you would need to start would be getData().
Simplest storage scenario would be to set up a timed interval to get the data , convert it to JSON and store it. Alternative would be to update your stored data every time use interacts with events.
A basic storage update function would be along the lines of:
function storeTimelineData(){
var data=timeline.getData();
localStorage.setItem('myTimeline', JSON.stringify(data));
}
Then when page loads you would need to check if there is data in localStorage , convert it to a javascript object using :
var storedData= JSON.parse( localStorage.getItem('myTimeline') );
And use this data to initialize the plugin if the data exists.
I have really just given you a basic overview. There are numerous details you will have to sort out from here
Related
I'm trying to integrate this fiddle: http://jsfiddle.net/jaredwilli/ReT8n/ in a fiddle I'm doing:
https://jsfiddle.net/vlrprbttst/99c8gn7k/
Basically you have a basket with some items inside of it, you can add or remove them. What I want is that, on page refresh, the html() of the .basket is kept in local storage. I'm stuck here:
https://jsfiddle.net/vlrprbttst/z8cffk4c/
I've put the forLocalStorage variable in the click handler because otherwise, the var wouldn't update itself but now I'm guessing that the final local storage code
if(localStorage.getItem('toDoData')) {
forLocalStorage = localStorage.getItem('toDoData');
}
is not working because it can't retrive the variable?
I've tried moving around things but I'm stuck here. what am i doing wrong?
You need to update DOM once your variable is set, e.g:
// LOCAL STORAGEEEEEEEE
if (localStorage.getItem('toDoData')) {
forLocalStorage = localStorage.getItem('toDoData');
$('#cart').html(forLocalStorage);
itemsCount();
}
Local storage can only store string key value pairs. I ensured you are passing in a string and also added a function to populate the cart on refresh, which resolved problems.
function populateCart() {
var items = localStorage.getItem('toDoData') || '';
$('#cart').html(items);
}
Added this call inside document.ready, like so: -
$(document).ready(function() {
populateCart();
// rest of code
});
Working CodePen: http://codepen.io/owenayres/pen/oxKmZg
You can do some light reading here on local storage. It is, in my opinion, best practice to store the data for the HTML as some JSON in local storage, which you would then loop through and regenerate the HTML for when reading this data again.
So, I have this weird thing going on in my test site, where I have every "link" (be it menu,button, or anything) to show/hide divs instead of loading pages. Pretty basic right? Except whenever I refresh the page, it all reverts back to the Homepage, which is expected. Based on my search for answers, I think I have to use the local/session storage option. Session sounds better.
So here's the deal. I looked up the w3schools page on sessionStorage and I get how it works, but I don't undestand how I could apply this to my page. Basically every link on my page runs a function that hides the previous div and shows a new one with the content. So I was thinking if every time a function triggered, it would store a value on a var that would appoint the function as the last used. Then somehow use sessionStorage and make it work, but I can't built it. Any help?
Here's a short example of my current code.
EDITED
var state = null;
function show1() {
state = "home";
"use strict";
document.getElementById('snow').style.display = "block";
document.getElementById('btn').style.display = "none";
}
function ramble() {
state = "ramble";
"use strict";
document.getElementById('ramble').style.display = "block";
document.getElementById('snow').style.display = "none";
document.getElementById('tex').style.display = "none";
}
That's basically it.Onclick show/hide.
You can use the following syntax:
Save data:
sessionStorage.setItem('key', 'value');
Retrieve data:
var data = sessionStorage.getItem('key');
More info and examples: https://developer.mozilla.org/en-US/docs/Web/API/Window/sessionStorage
The same goes with localStorage, but with the persistance differences you already found
I hope my solution will help you: If you want to keep your JS changes, you need to save them to database using AJAX and also change page architecture and logic to use data from database. After that, even if you reload page you will keep all your changes.
I have a simple main menu program.
HOW IT WORKS:
Simple, once you click level one and click on the done button, it unlocks level two, the problem is when you refresh the page it does not save it and level two is gone again.
Code I've tried:
I tried HTML Local storage, here are some examples I used
window.highestLevel = localStorage.getItem('highestLevel');
and stuff like that but I can't get it to save the level.
Please help here is a link. jsFiddle
Note: I want to use html local storage.
Save it with
window.localStorage.setItem('highestLevel', window.higestLevel);
Make sure you check that the browser you are working with supports localstorage. You could use Modernizr or something to do that easily.
To set something in localstorage:
javascript
localStorage.setItem('your-identifier', your-data);
So for example, to save a user's name:
javascript
localStorage.setItem('username', 'Luke Skywalker');
To get "username" back from localstorage:
javascript
localStorage.getItem('username');
Hope this helps!
You'll need to use getItem (as you did in your question) when you load the page, and hide level 2 as needed:
if (localStorage.getItem("highestLevel") <= 1) {
$("#level2").hide();
}
You'll also need to setItem to save when the user gets to level 2:
function mainMenuLvl2() {
localStorage.setItem("highestLevel", 2)
$('#level2').show();
}
Here's a JSFiddle: http://jsfiddle.net/ptcbkamx/2/
You can use localStorage and sessionStorage to store your data on client side like below
localStorage.setItem("variablename","value"); //--> this value is object type anything
var storedValue = localStorage.getItem("variablename");
or
sessionStorage.setItem("variablename","value");
var storedValue = sessionStorage.getItem("variablename");
You can use:
localStorage.setItem("highestLevel", window.highestLevel);
Then, if you want to get the highest level, use this:
localStorage.getItem("highestLevel", window.highestLevel);
I hope this helped!
I have two jQuery mobile pages (#list and #show). There are several items on the #list page with different IDs. If I click on item no.5, the ID no5 will be stored in localStorage and I will be redirected to page #show
Now the problem:
Storing the ID in localStorage works, but the next page shows me not the item no.5, but it shows me an old item, that was in the localStorage before.
script from page #list
localStorage.setItem("garageID", $(this).attr('id'));
window.location.replace("#show");
I encountered this problem too (and not on a mobile : on Chromium/linux).
As there doesn't seem to be a callback based API, I "fixed" it with a timeout which "prevents" the page to be closed before the setItem action is done :
localStorage.setItem(name, value);
setTimeout(function(){
// change location
}, 50);
A timeout of 0 might be enough but as I didn't find any specification (it's probably in the realm of bugs) and the problem isn't consistently reproduced I didn't take any chance. If you want you might test in a loop :
function setLocalStorageAndLeave(name, value, newLocation){
value = value.toString(); // to prevent infinite loops
localStorage.setItem(name, value);
(function one(){
if (localStorage.getItem(name) === value) {
window.location = newLocation;
} else {
setTimeout(one, 30);
}
})();
}
But I don't see how the fact that localStorage.getItem returns the right value would guarantee it's really written in a permanent way as there's no specification of the interruptable behavior, I don't know if the following part of the spec can be legitimately interpreted as meaning the browser is allowed to forget about dumping on disk when it leaves the page :
This specification does not require that the above methods wait until
the data has been physically written to disk. Only consistency in what
different scripts accessing the same underlying list of key/value
pairs see is required.
In your precise case, a solution might be to simply scroll to the element with that given name to avoid changing page.
Note on the presumed bug :
I didn't find nor fill any bug report as I find it hard to reproduce. In the cases I observed on Chromium/linux it happened with the delete operation.
Disclaimer: This solution isn't official and only tested for demo, not for production.
You can pass data between pages using $.mobile.changePage("target", { data: "anything" });. However, it only works when target is a URL (aka single page model).
Nevertheless, you still can pass data between pages - even if you're using Multi-page model - but you need to retrieve it manually.
When page is changed, it goes through several stages, one of them is pagebeforechange. That event carries two objects event and data. The latter object holds all details related to the page you're moving from and the page you're going to.
Since $.mobile.changePage() would ignore passed parameters on Multi-page model, you need to push your own property into data.options object through $.mobile.changePage("#", { options }) and then retrieve it when pagebeforechange is triggered. This way you won't need localstorage nor will you need callbacks or setTimeout.
Step one:
Pass data upon changing page. Use a unique property in order not to conflict with jQM ones. I have used stuff.
/* jQM <= v1.3.2 */
$.mobile.changePage("#page", { stuff: "id-123" });
/* jQM >= v1.4.0 */
$.mobile.pageContainer.pagecontainer("change", "#page", { stuff: "id-123" });
Step two:
Retrieve data when pagebeforechange is triggered on the page you're moving to, in your case #show.
$(document).on("pagebeforechange", function (event, data) {
/* check if page to be shown is #show */
if (data.toPage[0].id == "show") {
/* retrieve .stuff from data.options object */
var stuff = data.options.stuff;
/* returns id-123 */
console.log(stuff);
}
});
Demo
Hi I am a beginner web developer and am trying to build the interface of a simple e-commerce site as a personal project.The site has multiple pages with checkboxes.
When someone checks an element
it retrives the price of the element and
stores it in a variable.
But when I go to the next page and click on new checkboxes products the variable automaticly resets to its original state.
How can I save the value of that variable in Javascript?I am using the jQuery library.
EDIT:This is the code I've writen using sessionStorage but it still dosen't work when I move to next page the value is reseted.
How can I wright this code so that i dosen't reset on each page change.All pages on my website use the same script.
$(document).ready(function(){
var total = 0;
$('input.check').click(function(){
if($(this).attr('checked')){
var check = parseInt($(this).parent().children('span').text().substr(1 , 3));
total+=check;
sessionStorage.var_name=0 + total;
alert(sessionStorage.var_name);
}else{
var uncheck = parseInt($(this).parent().children('span').text().substr(1 , 3));
total-=uncheck;
}
})
The syntax for sessionStorage is simple, and it retains it's data until the browser window is closed. It acts exactly like any other javascript object. You can use dot-notation or square bracket notation (required for keys with spaces) to access stored values.
Storing values using sessionStorage
sessionStorage['value key'] = 'value to store';
Using stored values
alert(sessionStorage['value key']); // Alerts "value to store".
You could use localStorage to acomplish this. You'd need to set up a fallback for it, using localStorage however could be done like this:
Reading from storage:
if (localStorage['valueName'] !== undefined) {
input.value = localStorage['valueName'];
}
Writing to storage:
localStorage['valueName'] = input.value;
Here's a jsfiddle example: http://jsfiddle.net/yJjLe/
As already mentioned above you can use sessionStorage or localStorage. Another option available is HTML5 Web Databases
And take a look at this presentation.
Also keep in mind that html5 web storage is not secure as anyone can see your stored data simply from the console.