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I have some JS that stores the name and value of selected checkboxes on one page and then, on a button click, adds this data to a table on page 2.
This works, but now I am looking to do the same for a textbox containing a number. Specifically, I'm looking to take the value entered by the user and add this to a cell in the table. What would be the best way to approach this? Add to the existing function or create a separate on button click function specifically for the textbox value?
I have added a screenshot of the HTML table on page 2 along with where I would like the textbox value to go (highlighted with a red rectangle).
Here's what I have so far:
HTML for textbox (page 1):
<div class="selecttier">
<h1>5. Number of Clicks</h1>
<input id="numberofclickstextbox" name="numberofclicks" type="text" value="0" data-total="0" oninput="calculatetier()" />
</div>
JS on page 1:
$('#sales_order_form_button').click(function() {
let table_info = [];
$('input[type=checkbox]').each(
function(index, value) {
if($(this).is(':checked')) {
table_info.push(
{
name: $(this).attr('name'),
value: $(this).attr('value'),
}
);
}
});
let base64str=btoa(JSON.stringify(table_info));
window.location = "page2.html?table_data=" + base64str;
});
JS on page 2:
// Helper function
function getUrlParameter(name) {
name = name.replace(/[\[]/, '\\[').replace(/[\]]/, '\\]');
var regex = new RegExp('[\\?&]' + name + '=([^&#]*)');
var results = regex.exec(location.href);
return results === null ? '' : decodeURIComponent(results[1].replace(/\+/g, ' '));
};
// actual code
let table_data = getUrlParameter('table_data');
let data_from_page_1 = JSON.parse(atob(table_data));
for(let i = 0; i < data_from_page_1.length; i++){
let row = $("<tr></tr>");
let recordName = $("<td></td>").text(data_from_page_1[i].name);
let recordValue = $("<td></td>").text(data_from_page_1[i].value);
row.append(recordName, recordValue);
$('#output_table').append(row);
}
// code to sum CPC column
var sum1 = 0;
$("#output_table tr > td:nth-child(2)").each(
(_,el) => sum1 += Number($(el).text()) || 0
);
$("#sum1").text(sum1);
//datetime stamp
var dt = new Date();
document.getElementById("datetime").innerHTML = dt.toLocaleString();
Output HTML table (page 2):
<table id="output_table">
<tr>
<th>Name</th>
<th>Value</th>
<th>Number of Clicks</th>
</tr>
<tfoot>
<tr>
<th id="total" colspan="1">Total CPC:</th>
<td id="sum1"></td>
</tr>
</tfoot>
</table>
As stated in the #Manu Varghese comment, the way to go would be using sessionStorage or localStorage.
First, let's differentiate both. According to the Stack Overflow question "HTML5 Local storage vs Session Storage", we have the following answer:
localStorage and sessionStorage both extend Storage. There is no difference between them except for the intended "non-persistence" of sessionStorage.
That is, the data stored in localStorage persists until explicitly deleted. Changes made are saved and available for all current and future visits to the site.
For sessionStorage, changes are only available per tab. Changes made are saved and available for the current page in that tab until it is closed. Once it is closed, the stored data is deleted.
Considering they are used the same way and you must to choose between what better fits your case, I will proceed using sessionStorage.
For that, in the first page you must use:
sessionStorage.setItem("key", "value")
You may set the item right when you perceives a change, like in the input 'blur' event.
and when you land in the second page (right when jQuery calls its start event), you will retrieve your data using:
sessionStorage.getItem("key")
Take in mind that localStorage/sessionStorage can support a limited amount of data. Even if that limit is way bigger than URL, most browsers will store only 2.5MB to 10MB per origin, according to the browser implementation (you may test by yourself in the link recommended in MDN (Mozilla Development Network), http://dev-test.nemikor.com/web-storage/support-test/).
Also, you may want to avoid storing sensitive data in the storages, due to some some discussions about security, which seems not to be a complaint here.
Implementation in the given case
Your code can be modified in three steps:
Change the way you save the data to use the storage
Creates a JSON of an object containing the array, instead the make the JSON using the array itself. Then you can add more fields.
Load the JSON object and its fields (the array and the number).
Step 1 - Changing to sessionStorage
Just now you have your Javascript on page 1 creating an array of data and stringifying that data to a JSON string.
If you want to use the storage rather than the URL for all the data, just change these lines of code from:
let base64str=btoa(JSON.stringify(table_info));
window.location = "page2.html?table_data=" + base64str;
to the code that will save the data into a (local/session)Storage:
let jsonStr=JSON.stringify(table_info); // converts to JSON string
sessionStorage.setItem("oldData", jsonStr); // save to storage
window.location = "page2.html"; // navigate to other page
Notice that the storage can receive any string, but only strings, then we can remove the btoa function, but we must keep the stringify.
Step 2 -- Adding more data to save
Now you have one JSON that is an array of items. But what do you want is to include one more field, parallel to this array. Of course, you can't include it in the array, as it is a different thing. So, what we must to do is to create a JSON object which has a number field AND the array field itself.
Your function to create the array is all ok, then we will use the same "table_data" as the array and include it to a new JSON object:
let table_data = []; // the array you have
$('input[type=checkbox]').each(
... rest of code ...
); // the function that creates the array (I abbreviated it here)
// Creates an object with an array and a number
let jsonObj = {
table_data: table_data,
number_of_clicks: theNumberYouHave/* your variable with the number here */
};
// This is the bit above with CHANGES into variable names
// Instead of "table_data", now we save "jsonObj"
let jsonStr=JSON.stringify(jsonObj); // converts the "jsonObj" to a JSON string
sessionStorage.setItem("oldData", jsonStr);
window.location = "page2.html";
Remember to change "theNumberYouHave" to whatever your variable with the number is called. The you will append the number as a field of the JSON object.
In other words, this simply will create an structure like that:
{
number_of_clicks: 5216,
table_data: [
{ name: "...", value: "..."},
{ name: "...", value: "..."},
{ name: "...", value: "..."},
...
]
}
See? Your table_data is still there, but with a new sibling (number_of_clicks) inside an object.
Step 3 -- Loading data from page 1
For now, you have these two lines of code in page 2 to read data from page 1:
let table_data = getUrlParameter('table_data');
let data_from_page_1 = JSON.parse(atob(table_data));
What do you need there, is to simply replace the getUrlParameter function to read from the storage, and remove the atob function to reflect the changes we made in page 1, this way:
let jsonObj = sessionStorage.getItem("oldData"); // reads the string
let data_from_page_1 = JSON.parse(jsonObj); // parse the JSON string
let table_data = data_from_page_1.table_data; // grab the table data
let number_of_clicks = data_from_page_1.number_of_clicks; // grab the number
Now you are free to use the variable "table_data" like you did, and to use the "number_of_clicks" in the way you want to use it. It is the number passed from page 1, then you may set it to your table cell.
You have it with the unique ID "sum1", the you may just:
$("#sum1").text(number_of_clicks);
And you are done!
I highly recommend localStorage and sessionStorage to be used, as per this and this
Page 1 code full source
$('#next_page_button').click(function(){
let table_info = [];
// Do for checkboxes
$('.campaignstrategy input[type=checkbox]').each(
function(index, value){
if($(this).is(':checked')){
table_info.push(
{
name: $(this).attr('name'),
value: $(this).attr('value'),
type: 'checkbox'
}
);
}
});
$('.campaignstrategy input[type=text]').each(
function(index, value){
table_info.push(
{
name: $(this).attr('name'),
value: $(this).attr('value'),
type: 'text'
}
);
});
let base64str=btoa(JSON.stringify(table_info));
window.location = "page2.html?table_data=" + base64str;
});
Page 2 Code full source
// Helper function
function getUrlParameter(name) {
name = name.replace(/[\[]/, '\\[').replace(/[\]]/, '\\]');
var regex = new RegExp('[\\?&]' + name + '=([^&#]*)');
var results = regex.exec(location.href);
return results === null ? '' : decodeURIComponent(results[1].replace(/\+/g, ' '));
};
// actual code
let table_data = getUrlParameter('table_data');
let data_from_page_1 = JSON.parse(atob(table_data));
// clear table
$('#output_table').html("");
// generator checboxes
for(let i=0;i<data_from_page_1.length;i++){
if(data_from_page_1[i].type == "checkbox"){
let row = $("<tr></tr>");
let recordName = $("<td></td>").text(data_from_page_1[i].name);
let recordValue = $("<td></td>").text(data_from_page_1[i].value);
let recordCount = $("<td></td>").text("");
row.append(recordName, recordValue, recordCount); // not used but needed
$('#output_table').append(row);
}
}
// generate textboxes
for(let i=0;i<data_from_page_1.length;i++){
if(data_from_page_1[i].type == "text"){
let row = $("<tr></tr>");
let recordName = $("<td></td>").text("");
let recordValue = $("<td></td>").text("");
let recordCount = $("<td></td>").text(data_from_page_1[i].value);
row.append(recordName, recordValue, recordCount);
$('#output_table').append(row);
}
}
ANSWER:
What would be the best way to approach this?
window.localStorage - stores data with no expiration date
window.sessionStorage - stores data for one session
I want to create a JSON object with input variable. I have a 2 input field. when I click button i want to take input values and make a JSON object with that value. I cannot create a JSON object with entered value.
I try that
//getting the value of input as a variable
let id=document.querySelector("#id");
let title=document.querySelector("#title");
first I try the below. it sends a blank value instead of variable string
var vObj= '{"id":'+id.value+',"title":'+title.value+'}'
I also try that to
var vObj = {"id":{},"v_title":{}, "v_category":{}};
vObj.id=id.value;
vObj.title=title.value;
tried that
let asd=id.value;
let bsd=title.value;
var vObj = {id:asd, title:bsd}
it returns a blank value instead of variable value.
i am making a mistake that the trigger button has typo. i couldn't see that. sorry
You can create an object with name proeprties and then use JSON.stringify to turn this into valid JSON:
//let id = document.querySelector("#id").value;
let id = 'my_id';
//let title = document.querySelector("#title").value;
let title = 'my_title';
console.log('ID: ' + id);
console.log('Title: ' + title);
var vObj = { id: id, title: title };
var json = JSON.stringify(vObj);
console.log(json);
This line:
var vObj = { id: id, title: title };
Creates an object with an id with the value of the id variable, and a title with the value of the title variable.
This line:
var json = JSON.stringify(vObj);
Converts the object vObj to a JSON string.
Output:
ID: my_id
Title: my_title
{"id":"my_id","title":"my_title"}
Edit followimg #FelixKling comment
In ES6 it is possible to simplify the declaration of vObj using:
var vObj = {id, title};
This will create the same object with the assumed property names id and title. Obviously if your variable is not named id or title this will not work.
First create an object, then stringify it to JSON.
var jsonObj = JSON.stringify( { "id" : id, "title" : title } );
what I need
I need to toggle image on click.
like if user select favorite choice & then it mark unfavorite image is altered and data is deleted from localstoarge.
html code
<div style="display:block; float:right; width:auto; color:#7c7c7c;">
</div>
js code
function favaorite(sess_id,name,city,country,event_url,pointer){
var eventData;
//is anything in localstorage?
if (localStorage.getItem('eventData') === null) {
eventData = [];
} else {
// Parse the serialized data back into an array of objects
eventData = JSON.parse(localStorage.getItem('eventData'));
//alert(eventData);
$.each(eventData, function(key, value){
//console.log(value);
var imageUrl='http://im.gifbt.com/images/star1_phonehover.png';
//var imageUrl='http://im.gifbt.com/images/star1_phone.png';
$(pointer).closest('.evt_date').find('.favourate_dextop').css('background-image', 'url("' + imageUrl + '")');
//$(pointer).closest('.evt_date').find('.favourate_dextop').css('background-image', 'url("' + imageUrl + '")');
});
}
var details={};
details.sess_id=sess_id;
details.name=name;
details.city=city;
details.country=country;
details.event_url=event_url;
// Push the new data (whether it be an object or anything else) onto the array
eventData.push(details);
// Alert the array value
//alert(eventData); // Should be something like [Object array]
// Re-serialize the array back into a string and store it in localStorage
var jsondata=localStorage.setItem('eventData', JSON.stringify(eventData));
}
problem
I'm new in localstorage I need to know how could I delete data from json string.
I have implemented add to favorite now I need to mark unfavorite.
data is stored:
[{
"sess_id":182104,
"name":"AUTOMECH FORMULA",
"city":"Cairo",
"country":"Egypt",
"event_url":"automech-formula"
},]
To delete data from localstorage you use localStorage.removeItem('itemNam')
example
localStorage.setItem('name','hello');
to delete the name item from the localStorage you use
localStorage.removeItem('name');
BUT IF YOUR QUESTION IS HOW TO DELETE DATA FROM JSON OBJECT THEN YOU HAVE TWO METHODS
1: changing the original json object
delete originalJson.attributeName
originalJson = {name:'myname',age:30};//our object to test with
example :
delete originalJson.age //in this case originalJson.age is no more available
2: don't change the original object and make another copy instead
originalJson2 = JSON.stringify(originalJson);
originalJson2 = JSON.parse(originalJson2);
delete originalJson2.age //originalJson.age is available but originalJson2.age is not available
here is the : jsfiddle
let assume that sess_id is your unique id for events
function unfavorite(sess_id){
var eventData = localStorage.getItem('eventData');
//is anything in localstorage?
if (localStorage.getItem('eventData') === null) {
console.log('invalid event');
}
eventData = JSON.parse(eventData);
// Keep all without the one with specified sess_id
$.grep(eventData, function(value) {
return value.sess_id != sess_id;
});
var jsondata=localStorage.setItem('eventData', JSON.stringify(eventData));
}
I'm attempting to add/remove entries from a Firebase database. I want to list them in a table to be added/modified/removed (front end) but I need a way to uniquely identify each entry in order to modify/remove. Firebase adds a unique identifier by default when using push(), but I didn't see anything referencing how to select this unique identifier in the API documentation. Can this even be done? Should I be using set() instead so I'm creating the unique ID?
I've put this quick example together using their tutorial:
<div id='messagesDiv'></div>
<input type='text' class="td-field" id='nameInput' placeholder='Name'>
<input type='text' class="td-field" id='messageInput' placeholder='Message'>
<input type='text' class="td-field" id='categoryInput' placeholder='Category'>
<input type='text' class="td-field" id='enabledInput' placeholder='Enabled'>
<input type='text' class="td-field" id='approvedInput' placeholder='Approved'>
<input type='Button' class="td-field" id='Submit' Value="Revove" onclick="msgRef.remove()">
<script>
var myDataRef = new Firebase('https://unique.firebase.com/');
$('.td-field').keypress(function (e) {
if (e.keyCode == 13) {
var name = $('#nameInput').val();
var text = $('#messageInput').val();
var category = $('#categoryInput').val();
var enabled = $('#enabledInput').val();
var approved = $('#approvedInput').val();
myDataRef.push({name: name, text: text, category: category, enabled: enabled, approved: approved });
$('#messageInput').val('');
}
});
myDataRef.on('child_added', function(snapshot) {
var message = snapshot.val();
displayChatMessage(message.name, message.text, message.category, message.enabled, message.approved);
});
function displayChatMessage(name, text, category, enabled, approved, ) {
$('<div/>').text(text).prepend($('<em/>').text(name+' : '+category +' : '+enabled +' : '+approved+ ' : ' )).appendTo($('#messagesDiv'));
$('#messagesDiv')[0].scrollTop = $('#messagesDiv')[0].scrollHeight;
};
</script>
Now lets assume I have three rows of data:
fred : 1 : 1 : 1 : test message 1
fred : 1 : 1 : 1 : test message 2
fred : 1 : 1 : 1 : test message 3
How do I go about uniquely identifying row 2?
in the Firebase Database they look like this:
-DatabaseName
-IuxeSuSiNy6xiahCXa0
approved: "1"
category: "1"
enabled: "1"
name: "Fred"
text: "test message 1"
-IuxeTjwWOhV0lyEP5hf
approved: "1"
category: "1"
enabled: "1"
name: "Fred"
text: "test message 2"
-IuxeUWgBMTH4Xk9QADM
approved: "1"
category: "1"
enabled: "1"
name: "Fred"
text: "test message 3"
To anybody finding this question & using Firebase 3+, the way you get auto generated object unique ids after push is by using the key property (not method) on the promise snapshot:
firebase
.ref('item')
.push({...})
.then((snap) => {
const key = snap.key
})
Read more about it in the Firebase docs.
As a side note, those that consider generating their own unique ID should think twice about it. It may have security and performance implications. If you're not sure about it, use Firebase's ID. It contains a timestamp and has some neat security features out of the box.
More about it here:
The unique key generated by push() are ordered by the current time, so the resulting list of items will be chronologically sorted. The keys are also designed to be unguessable (they contain 72 random bits of entropy).
To get the "name" of any snapshot (in this case, the ID created by push()) just call name() like this:
var name = snapshot.name();
If you want to get the name that has been auto-generated by push(), you can just call name() on the returned reference, like so:
var newRef = myDataRef.push(...);
var newID = newRef.name();
NOTE:
snapshot.name() has been deprecated. See other answers.
snapshot.name() has been deprecated. use key instead. The key property on any DataSnapshot (except for one which represents the root of a Firebase) will return the key name of the location that generated it. In your example:
myDataRef.on('child_added', function(snapshot) {
var message = snapshot.val();
var id = snapshot.key;
displayChatMessage(message.name, message.text, message.category, message.enabled, message.approved);
});
To get uniqueID after push() you must use this variant:
// Generate a reference to a new location and add some data using push()
var newPostRef = postsRef.push();
// Get the unique key generated by push()
var postId = newPostRef.key;
You generate a new Ref when you push() and using .key of this ref you can get uniqueID.
As #Rima pointed out, key() is the most straightforward way of getting the ID firebase assigned to your push().
If, however, you wish to cut-out the middle-man, Firebase released a gist with their ID generation code. It's simply a function of the current time, which is how they guarantee uniqueness, even w/o communicating w/ the server.
With that, you can use generateId(obj) and set(obj) to replicate the functionality of push()
Here's the ID function:
/**
* Fancy ID generator that creates 20-character string identifiers with the following properties:
*
* 1. They're based on timestamp so that they sort *after* any existing ids.
* 2. They contain 72-bits of random data after the timestamp so that IDs won't collide with other clients' IDs.
* 3. They sort *lexicographically* (so the timestamp is converted to characters that will sort properly).
* 4. They're monotonically increasing. Even if you generate more than one in the same timestamp, the
* latter ones will sort after the former ones. We do this by using the previous random bits
* but "incrementing" them by 1 (only in the case of a timestamp collision).
*/
generatePushID = (function() {
// Modeled after base64 web-safe chars, but ordered by ASCII.
var PUSH_CHARS = '-0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz';
// Timestamp of last push, used to prevent local collisions if you push twice in one ms.
var lastPushTime = 0;
// We generate 72-bits of randomness which get turned into 12 characters and appended to the
// timestamp to prevent collisions with other clients. We store the last characters we
// generated because in the event of a collision, we'll use those same characters except
// "incremented" by one.
var lastRandChars = [];
return function() {
var now = new Date().getTime();
var duplicateTime = (now === lastPushTime);
lastPushTime = now;
var timeStampChars = new Array(8);
for (var i = 7; i >= 0; i--) {
timeStampChars[i] = PUSH_CHARS.charAt(now % 64);
// NOTE: Can't use << here because javascript will convert to int and lose the upper bits.
now = Math.floor(now / 64);
}
if (now !== 0) throw new Error('We should have converted the entire timestamp.');
var id = timeStampChars.join('');
if (!duplicateTime) {
for (i = 0; i < 12; i++) {
lastRandChars[i] = Math.floor(Math.random() * 64);
}
} else {
// If the timestamp hasn't changed since last push, use the same random number, except incremented by 1.
for (i = 11; i >= 0 && lastRandChars[i] === 63; i--) {
lastRandChars[i] = 0;
}
lastRandChars[i]++;
}
for (i = 0; i < 12; i++) {
id += PUSH_CHARS.charAt(lastRandChars[i]);
}
if(id.length != 20) throw new Error('Length should be 20.');
return id;
};
})();
You can update record adding the ObjectID using a promise returned by .then() after the .push() with snapshot.key:
const ref = Firebase.database().ref(`/posts`);
ref.push({ title, categories, content, timestamp})
.then((snapshot) => {
ref.child(snapshot.key).update({"id": snapshot.key})
});
If you want to get the unique key generated by the firebase push() method while or after writing to the database without the need to make another call, here's how you do it:
var reference = firebaseDatabase.ref('your/reference').push()
var uniqueKey = reference.key
reference.set("helllooooo")
.then(() => {
console.log(uniqueKey)
// this uniqueKey will be the same key that was just add/saved to your database
// can check your local console and your database, you will see the same key in both firebase and your local console
})
.catch(err =>
console.log(err)
});
The push() method has a key property which provides the key that was just generated which you can use before, after, or while you write to the database.
Use push() to get a new reference and key to get the the unique id of the it.
var ref = FirebaseDatabase.instance.ref();
var newRef = ref.push(); // Get new key
print(newRef.key); // This is the new key i.e IqpDfbI8f7EXABCma1t
newRef.set({"Demo": "Data"}) // Will be set under the above key
How i did it like:
FirebaseDatabase mFirebaseDatabase = FirebaseDatabase.getInstance();
DatabaseReference ref = mFirebaseDatabase.getReference().child("users").child(uid);
String key = ref.push().getKey(); // this will fetch unique key in advance
ref.child(key).setValue(classObject);
Now you can retain key for further use..
The requirement is following:
I have to get the location field from page.
var input= global.input = document.getElementById("Location");
Get the neighborhood area from the json file based on input and show on the page.
I have a json object and have to filter the data from the json object based on the key value (location)
var inputLocation=input.value;
In my javascript I am getting the error if I use dynamic the key.
I am able to get the json array if I do this data.Aspen but i have to get the data from a text field and it can be different so if I call data.inputLocation... its coming undefined
when i use data.(inputLocation.value) getting the following error :
XML filter is applied to non-XML value ({Aspen:[{ID:
{
"Aspen":[
{
"ID":"Bellaire",
"Name":"Bellaire"
},
{
"ID":"Champions Forest",
"Name":"Champions Forest"
},
{
"ID":"Highland Village",
"Name":"Highland Village"
},
{
"ID":"Museum District",
"Name":"Museum District"
}
]
}
You can access the property using array-like syntax:
data[inputLocation]
If inputLocation is set to "Aspen", then it is the same as these two lines:
data["Aspen"]
data.Aspen
get value from dynamic json object Using real time currency converter rest api responce
public async Task<JsonResult> ConvertCurrency(float Price, string FromCurrency)
{
var testcase = FromCurrency + "_USD";
WebClient web = new WebClient();
const string ConverterApiURL = "http://free.currencyconverterapi.com/api/v5/convert?q={0}_{1}&compact=ultra&apiKey={{EnterKey}}";
string url = String.Format(ConverterApiURL, FromCurrency, "USD");
string response = new WebClient().DownloadString(url);
var data = (JObject)JsonConvert.DeserializeObject(response);
dynamic result = data.SelectToken(testcase + ".val").ToString();
var basePrice = float.Parse(result);
double exchangeRate = Price * basePrice;
var responce = Math.Round(exchangeRate, 2);
return Json(responce, JsonRequestBehavior.AllowGet);
}