How to apply localStorage or javascript Cookies on my program?
Question
I have researched some websites about localStorage and javascript cookies and I tried to apply it but no luck, it always didn't worked. I want to apply localStorage or javascript cookies on my assignment. A simple reservation subject. I want the browser to remember the changes that I made in the browser.
Javascript:
<script type="text/javascript">
var availableSlot1 = 5;
var reduceSlot1 = function(valueToDeduct1){
availableSlot1 = availableSlot1 - valueToDeduct1;
document.getElementById('ite164').innerHTML = availableSlot1;
if (availableSlot1 == 0){
document.getElementById('ite164').innerHTML = "FULL";
document.getElementById("ite164").style.color = "red";
document.getElementById("number1").style.color = "red";
document.getElementById("subject1").style.color = "red";
document.getElementById("code1").style.color = "red";
document.getElementById("units1").style.color = "red";
document.getElementById("prof1").style.color = "red";
document.getElementById("1").style.display = "none";
}
};
var availableSlot2 = 5;
var reduceSlot2 = function(valueToDeduct2){
availableSlot2 = availableSlot2 - valueToDeduct2;
document.getElementById('phi001').innerHTML = availableSlot2;
if (availableSlot2 == 0){
document.getElementById('phi001').innerHTML = "FULL";
document.getElementById("phi001").style.color = "red";
document.getElementById("number2").style.color = "red";
document.getElementById("subject2").style.color = "red";
document.getElementById("code2").style.color = "red";
document.getElementById("units2").style.color = "red";
document.getElementById("prof2").style.color = "red";
document.getElementById("2").style.display = "none";
}
};
var availableSlot3 = 5;
var reduceSlot3 = function(valueToDeduct3){
availableSlot3 = availableSlot3 - valueToDeduct3;
document.getElementById('ite165').innerHTML = availableSlot3;
if (availableSlot3 == 0){
document.getElementById('ite165').innerHTML = "FULL";
document.getElementById("ite165").style.color = "red";
document.getElementById("number3").style.color = "red";
document.getElementById("subject3").style.color = "red";
document.getElementById("code3").style.color = "red";
document.getElementById("units3").style.color = "red";
document.getElementById("prof3").style.color = "red";
document.getElementById("3").style.display = "none";
}
};
var availableSlot4 = 5;
var reduceSlot4 = function(valueToDeduct4){
availableSlot4 = availableSlot4 - valueToDeduct4;
document.getElementById('ite048').innerHTML = availableSlot4;
if (availableSlot4 == 0){
document.getElementById('ite048').innerHTML = "FULL";
document.getElementById("ite048").style.color = "red";
document.getElementById("number4").style.color = "red";
document.getElementById("subject4").style.color = "red";
document.getElementById("code4").style.color = "red";
document.getElementById("units4").style.color = "red";
document.getElementById("prof4").style.color = "red";
document.getElementById("4").style.display = "none";
}
};
var availableSlot5 = 5;
var reduceSlot5 = function(valueToDeduct5){
availableSlot5 = availableSlot5 - valueToDeduct5;
document.getElementById('ite136').innerHTML = availableSlot5;
if (availableSlot5 == 0){
document.getElementById('ite136').innerHTML = "FULL";
document.getElementById("ite136").style.color = "red";
document.getElementById("number5").style.color = "red";
document.getElementById("subject5").style.color = "red";
document.getElementById("code5").style.color = "red";
document.getElementById("units5").style.color = "red";
document.getElementById("prof5").style.color = "red";
document.getElementById("5").style.display = "none";
}
};
Jquery:
<script>
$(document).ready(function(){
$("#button1").hide();
$("#button2").hide();
$("#button3").hide();
$("#button4").hide();
$("#button5").hide();
$("#button6").hide();
$("#button7").hide();
$("#1").click(function(){
$("#button1").show();
$("#button1").fadeIn(1000);
$("#button2").hide();
$("#button3").hide();
$("#button4").hide();
$("#button5").hide();
$("#button6").hide();
$("#button7").hide();
$("#button1").click(function() {
$("#button1").hide();
});
});
$("#2").click(function(){
$("#button1").hide();
$("#button2").show();
$("#button2").fadeIn(1000);
$("#button3").hide();
$("#button4").hide();
$("#button5").hide();
$("#button6").hide();
$("#button7").hide();
$("#button2").click(function() {
$("#button2").hide();
});
});
$("#3").click(function(){
$("#button1").hide();
$("#button2").hide();
$("#button3").show();
$("#button3").fadeIn(1000);
$("#button4").hide();
$("#button5").hide();
$("#button6").hide();
$("#button7").hide();
$("#button3").click(function() {
$("#button3").hide();
});
});
$("#4").click(function(){
$("#button1").hide();
$("#button2").hide();
$("#button3").hide();
$("#button4").show();
$("#button4").fadeIn(1000);
$("#button5").hide();
$("#button6").hide();
$("#button7").hide();
$("#button4").click(function() {
$("#button4").hide();
});
});
$("#5").click(function(){
$("#button1").hide();
$("#button2").hide();
$("#button3").hide();
$("#button4").hide();
$("#button5").show();
$("#button5").fadeIn(1000);
$("#button6").hide();
$("#button7").hide();
$("#button5").click(function() {
$("#button5").hide();
});
});
$("#6").click(function(){
$("#button1").hide();
$("#button2").hide();
$("#button3").hide();
$("#button4").hide();
$("#button5").hide();
$("#button6").show();
$("#button6").fadeIn(1000);
$("#button7").hide();
$("#button6").click(function() {
$("#button6").hide();
});
});
$("#7").click(function(){
$("#button1").hide();
$("#button2").hide();
$("#button3").hide();
$("#button4").hide();
$("#button5").hide();
$("#button6").hide();
$("#button7").show();
$("#button7").fadeIn(1000);
$("#button7").click(function() {
$("#button7").hide();
});
});
});
</script>
HTML:
<table border="1" width="700px">
<tr>
<th>#</th>
<th>Subjects</th>
<th>Subject Code</th>
<th>Units</th>
<th>Instructor</th>
<th>Available Slots</th>
</tr>
<tr>
<td class="center" id="number1">1</td>
<td id="subject1">Data Comm. Systems & Networking</td>
<td class="center" id="code1">ITE164</td>
<td class="center" id="units1">3.0</td>
<td id="prof1">Quinito, Floreto Jr. R.</td>
<td style="text-align: center;"><span id="ite164">5</span></td>
</tr>
<tr>
<td class="center" id="number2">2</td>
<td id="subject2">Introduction to Philosophy and Logic</td>
<td class="center" id="code2">PHI001</td>
<td class="center" id="units2">3.0</td>
<td id="prof2">Chiong, Isidro R.</td>
<td style="text-align: center;"><span id="phi001">5</span></td>
</tr>
<tr>
<td class="center" id="number3">3</td>
<td id="subject3">Basic Finance & Acctg. Principles for IT</td>
<td class="center" id="code3">ITE165</td>
<td class="center" id="units3">3.0</td>
<td id="prof3">Cadelinia, Godofredo B.</td>
<td style="text-align: center;"><span id="ite165">5</span></td>
</tr>
<tr>
<td class="center" id="number4">4</td>
<td id="subject4">Discrete Structures</td>
<td class="center" id="code4">ITE048</td>
<td class="center" id="units4">3.0</td>
<td id="prof4">Calibara, Eunelfa Regie F.</td>
<td style="text-align: center;"><span id="ite048">5</span></td>
</tr>
<tr>
<td class="center" id="number5">5</td>
<td id="subject5">Web Page Design</td>
<td class="center" id="code5">ITE136</td>
<td class="center" id="units5">3.0</td>
<td id="prof5">Pequiro, Chemby Mae S.</td>
<td style="text-align: center;"><span id="ite136">5</span></td>
</tr>
<tr>
<td class="center" id="number6">6</td>
<td id="subject6">Systems Analysis and Design</td>
<td class="center" id="code6">ITE062</td>
<td class="center" id="units6">3.0</td>
<td id="prof6">Galudo, Darwin M.</td>
<td style="text-align: center;"><span id="ite062">5</span></td>
</tr>
<tr>
<td class="center" id="number7">7</td>
<td id="subject7">Operating System</td>
<td class="center" id="code7">ITE076</td>
<td class="center" id="units7">3.0</td>
<td id="prof7">Lagala, Glenn T.</td>
<td style="text-align: center;"><span id="ite076">5</span></td>
</tr>
</table>
<div id="combobox">
<span style="color: white;">Select a subject to reserve:</span>
<select>
<option id="1" value="ITE164">Data Comm. Systems & Networking (ITE164)</option>
<option id="2" value="PHI001">Introduction to Philosophy and Logic (PHI001)</option>
<option id="3" value="ITE165">Basic Finance & Acctg. Principles for IT (ITE165)</option>
<option id="4" value="ITE048">Discrete Structures (ITE048)</option>
<option id="5" value="ITE136">Web Page Design (ITE136)</option>
<option id="6" value="ITE062">Systems Analysis and Design (ITE062)</option>
<option id="7" value="ITE076">Operating System (ITE076)</option>
</select>
<a href="javascript:reduceSlot1(1)" id="button1"><input type="button" value="Reserve"></a>
<a href="javascript:reduceSlot2(1)" id="button2"><input type="button" value="Reserve"></a>
<a href="javascript:reduceSlot3(1)" id="button3"><input type="button" value="Reserve"></a>
<a href="javascript:reduceSlot4(1)" id="button4"><input type="button" value="Reserve"></a>
<a href="javascript:reduceSlot5(1)" id="button5"><input type="button" value="Reserve"></a>
<a href="javascript:reduceSlot6(1)" id="button6"><input type="button" value="Reserve"></a>
<a href="javascript:reduceSlot7(1)" id="button7"><input type="button" value="Reserve"></a>
</div>
I am sorry for the very messy code, I am still a newbie. Can you help me?
3 answers
solution1
2 2013-10-06 03:58:29
Local Storage will work for what you are trying to do better than cookies. Basically, there is an array-like object on the window called localStorage . You can use it to store arbitrary strings only. Like:
window.localStorage["button1_is_showing"] = true;
or:
window.localstorage.button1_is_showing = true;
The true boolean value will be turned into the string "true" . To turn it into a boolean again some time later:
var b1showing;
if (window.localStorage.button1_is_showing == "true") {
b1showing = true;
}
else {
b1showing = false;
}
You could also use the browser's JSON parser for this:
var b1showing = JSON.parse(window.localStorage.button1_is_showing);
But bear in mind that that does not have strong browser support: http://caniuse.com/#search=JSON
Whatever strings you store in localStorage will stay there until the browser clears its cookies, or until you delete something like this:
delete window.localStorage.b1showing;
For your particular example: every time the user clicks a button, create one object in localStorage for each button that will store the buttons state. Then, when the page is loaded (in your ready event), loop through the localstorage checking what is there and hide/show the buttons depending on that.
A side note: using classes instead of 7 different ids is much more flexible, readable, and fast.
EDIT: Another excellent source: http://diveintohtml5.info/storage.html
Tons more info here: https://developer.mozilla.org/en-US/docs/Web/Guide/API/DOM/Storage
solution2
1 2013-10-06 04:55:08
you can use something like this..
<table id="slotTable" border="1" width="700px">
<tr>
<th>#</th>
<th>Subjects</th>
<th>Subject Code</th>
<th>Units</th>
<th>Instructor</th>
<th>Available Slots</th>
</tr>
<tr >
<td class="center" id="number1">1</td>
<td id="subject1">Data Comm. Systems & Networking</td>
<td class="center" id="code1">ITE164</td>
<td class="center" id="units1">3.0</td>
<td id="prof1">Quinito, Floreto Jr. R.</td>
<td style="text-align: center;">5</td>
</tr>
<tr>
<td class="center" id="number2">2</td>
<td id="subject2">Introduction to Philosophy and Logic</td>
<td class="center" id="code2">PHI001</td>
<td class="center" id="units2">3.0</td>
<td id="prof2">Chiong, Isidro R.</td>
<td style="text-align: center;">5</td>
</tr>
<tr>
<td class="center" id="number3">3</td>
<td id="subject3">Basic Finance & Acctg. Principles for IT</td>
<td class="center" id="code3">ITE165</td>
<td class="center" id="units3">3.0</td>
<td id="prof3">Cadelinia, Godofredo B.</td>
<td style="text-align: center;">5</td>
</tr>
<tr>
<td class="center" id="number4">4</td>
<td id="subject4">Discrete Structures</td>
<td class="center" id="code4">ITE048</td>
<td class="center" id="units4">3.0</td>
<td id="prof4">Calibara, Eunelfa Regie F.</td>
<td style="text-align: center;">5</td>
</tr>
<tr>
<td class="center" id="number5">5</td>
<td id="subject5">Web Page Design</td>
<td class="center" id="code5">ITE136</td>
<td class="center" id="units5">3.0</td>
<td id="prof5">Pequiro, Chemby Mae S.</td>
<td style="text-align: center;">5</td>
</tr>
<tr>
<td class="center" id="number6">6</td>
<td id="subject6">Systems Analysis and Design</td>
<td class="center" id="code6">ITE062</td>
<td class="center" id="units6">3.0</td>
<td id="prof6">Galudo, Darwin M.</td>
<td style="text-align: center;">5</td>
</tr>
<tr>
<td class="center" id="number7">7</td>
<td id="subject7">Operating System</td>
<td class="center" id="code7">ITE076</td>
<td class="center" id="units7">3.0</td>
<td id="prof7">Lagala, Glenn T.</td>
<td style="text-align: center;"><span id="ite076">5</span></td>
</tr>
</table>
<div id="combobox">
<span style="color: white;">Select a subject to reserve:</span>
<select onchange="updateCurrentSlot(this.value)" >
<option id="1" value="ITE164">Data Comm. Systems & Networking (ITE164)</option>
<option id="2" value="PHI001">Introduction to Philosophy and Logic (PHI001)</option>
<option id="3" value="ITE165">Basic Finance & Acctg. Principles for IT (ITE165)</option>
<option id="4" value="ITE048">Discrete Structures (ITE048)</option>
<option id="5" value="ITE136">Web Page Design (ITE136)</option>
<option id="6" value="ITE062">Systems Analysis and Design (ITE062)</option>
<option id="7" value="ITE076">Operating System (ITE076)</option>
</select>
<a href="javascript:reduceSlot(1)" id="button"><input type="button" value="Reserve"></a>
</div>
and the script..
<script>
// the currentSlot holds which slot is being seleted..
var currentSlot = 0 ;
// check if data is already stored in the localStorage.. if not create a new one..
if (!localStorage.slots) {
var slots = [
{'slotId' : 0 , 'slotVal' : 'ITE164' ,'availableSlot' : 5 },
{'slotId' : 1 , 'slotVal' : 'PHI001' ,'availableSlot' : 5 },
{'slotId' : 2 , 'slotVal' : 'ITE165' ,'availableSlot' : 5 },
{'slotId' : 3 , 'slotVal' : 'ITE048' ,'availableSlot' : 5 },
{'slotId' : 4 , 'slotVal' : 'ITE136' ,'availableSlot' : 5 },
{'slotId' : 5 , 'slotVal' : 'ITE062' ,'availableSlot' : 5 },
{'slotId' : 6 , 'slotVal' : 'ITE076' ,'availableSlot' : 5 }
] ;
}
else if( localStorage.slots) {
$(document).ready(function () {
slots = JSON.parse(localStorage.slots) ;
// update the slots accordig to the locally stored data
$("#slotTable tr").each(function(index) {
if(index >=1 ) { // index 0 will be <th>
// as 6th child of tr contains available slot..
$(this).find(':nth-child(6)').text(slots[index-1].availableSlot) ;
// checking if slots are full..
if(slots[index-1].availableSlot === 0 ) { $(this).find('td').css({'color' : 'red'}) ;
$(this).find(':nth-child(6)').text("Full") ;
}
}
});
}) ;
}
// function to reduce the current selected slot..
function reduceSlot(reduceAmt) {
// if availableSlot is 1.. and is reduced.. it will be full..
if (slots[currentSlot].availableSlot == 1 ) {
// setting the requred stuff..
$("#slotTable tr").each(function(index) {
if(index == currentSlot+1) {
$(this).find('td').css({'color' : 'red'});
$(this).find(':nth-child(6)').text("Full") ;
slots[currentSlot].availableSlot = 0 ;
}
});
}
// we have to reduce slot and update our 'slots' variable as well as the table data
else if (slots[currentSlot].availableSlot > 1) {
slots[currentSlot].availableSlot = slots[currentSlot].availableSlot - reduceAmt ;
$("#slotTable tr").each(function(index) {
if(index == currentSlot+ 1) $(this).find(':nth-child(6)').text(slots[currentSlot].availableSlot) ;
});
}
// save data in localStorage
localStorage.slots = JSON.stringify(slots) ;
}
// when the option in select changes.. we have to update our currentSlot variable.
function updateCurrentSlot(sVal) {
for(i=0;i<slots.length;i++) {
if(slots[i].slotVal === sVal) currentSlot = slots[i].slotId ;
}
}
</script>
solution3
0 2013-10-06 04:37:26
Firstly, there is onclick event on a select.
Change
$("#1").click(function(){...
to
$("#select_id").change(function() {...
See examples here to learn more.
As you are already using jquery, perhaps it would easier to use jquery cookies plugin - https://github.com/carhartl/jquery-cookie
$.cookie("test", 1); $.removeCookie("test");
If you dont want to use a plugin, have a look at this quirksmode
Look at the other answer if you want to use localstorage :)
Cheers!!
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