I have 5 information coming at the same time like "long", "lat", "speed", "immat", and "date". At first, every 0.1 second new 5 of the info comes in for as long as info still available, then each time another set of the new 5 info available, another round of the same thing happen. I would like to know how to temporary keep all this values and display it.
var myPin = Table_Pins[immat];
myPin.Lat[i] = document.getElementById("Lat");
myPin.Long[i] = document.getElementById("Long");
myPin.immat[i] = document.getElementById("immat");
myPin.date[i] = document.getElementById("date");
myPin.speed[i] = document.getElementById("vitesse");
for (i=0; i<myPin.length; i++){
document.write("lat=" +myPin.Lat[i]);
document.write("long=" +myPin.Long[i]);
document.write("immat=" +myPin.immat[i]);
document.write("date=" +myPin.date[i]);
document.write("speed=" +myPin.speed[i]);
}
Use Object to store data inside an Array:
var pins = []; //this will contain a list of your objects, it's better than keeping an object containing arrays
//inside your function that stores data you will have this
var pin = {
lat: document.getElementById('Lat'),
long: document.getElementById('Long'),
immat: document.getElementById('immat'),
date: document.getElementById('date'),
speed: document.getElementById('vitesse')
};
pins.push(pin);
//and after pushing it you could add to DOM dynamically without looping over al the pins
Assuming that you have a <ul> with id="pins" you can do something similar(just after the pins.push(pin)):
var pinUl = document.getElementById('pins'); //you can declare this after pins
//and now the code that adds an element to the HTML page
var pinLi = "<li>" + JSON.stringify(pin) + "</li>";
pinUl.innerHTML += pinLi; //append the pin at the end of the other
See this example
Remember to avoid document.write!
it's just a problem of global and local variance.Avoid defined var map in function when already defined var map = null in global. Only "map"is enough without "var" in a function.
Related
I am trying to save my variables in an array. Theses variables are written in by the user and saved to localStorage when a button is pressed. On my other html page i reach these variables and put them in 3 different arrays(the variables, that go in three arrays). Then the user writes in new text and save to the variables. Now to the problem. The newly created variables don't add to the array, they replace. I'm thinking this is due to to the same variable name however I can't find an solution.
I have tried to change variable names etc for saving the new variable but cant find solution.
//This is html page 2 (gets the items from localhost)
var TankaKostnadVar = localStorage.getItem("StorageKostnadVar");
var TankaLiterVar= localStorage.getItem("StorageLiterVar");
var TankaDatumVar = localStorage.getItem("StorageDatumVar");
var arrayKostnad = [];
var arrayLiter = [];
var arrayDatum = [];
arrayKostnad.push(TankaKostnadVar,);
arrayLiter.push(TankaLiterVar,);
arrayDatum.push(TankaDatumVar,);
document.write(arrayLiter,arrayKostnad,arrayDatum); //Ignore this, just test
//This is the code where the user is writing and it saves to localStorage.
//Html page 1 that saves the variables
var TankaKostnadVar = document.getElementById("tankaKostnad").value;
var TankaLiterVar = document.getElementById("tankaLiter").value;
var TankaDatumVar = document.getElementById("tankaDatum").value;
localStorage.setItem("StorageKostnadVar", TankaKostnadVar);
localStorage.setItem("StorageLiterVar", TankaLiterVar);
localStorage.setItem("StorageDatumVar", TankaDatumVar);
I expect the array to add the variable. So if the user writes an 5 the array should first be [5] then when the user writes an 8 the array should be [5,8]
If you don't want use JSON, you can save string comma separated and, when necessary, transform the items to numbers. To transform in numbers you can use map function or a for. Localstorage only save strings, so if you need to be back to numbers you need to use JSON.parse or use function parseInt, that is global.
//Retrieve saved items from localstorage
var TankaKostnadVar = localStorage.getItem("StorageKostnadVar"); // "1,2"
var TankaLiterVar = localStorage.getItem("StorageLiterVar");
var TankaDatumVar = localStorage.getItem("StorageDatumVar");
TankaKostnadVar += "," + document.getElementById("tankaKostnad").value;
TankaLiterVar += "," + document.getElementById("tankaLiter").value;
TankaDatumVar += "," + document.getElementById("tankaDatum").value;
localStorage.setItem("StorageKostnadVar", TankaKostnadVar);
localStorage.setItem("StorageLiterVar", TankaLiterVar);
localStorage.setItem("StorageDatumVar", TankaDatumVar);
// if you want to transform TankaKostnadVar and others two, just do like this
TankaKostnadVar.split(','); // result: ['1', '2']
// if you want to transform to number
TankaKostnadVar = TankaKostnadVar.split(',').map( function(number) {
return parseInt(number)
} );
The split function of string, breaks a strings in parts separated by one string. In this case, breaks a string separated with comma. So "1,2" turns into ['1', '2'].
If you want to keep adding to the array you'll need to push the entire array you're holding in memory up to localStorage after appending a new element. Alos, localStorage only stores string values so if you want to maintain the Array structure you'll have to use JSON.stringify() before running setItem() and then JSON.parse() next time you access those values with getItem().
//This is the code where the user is writing and it saves to localStorage.
//Html page 1 that saves the variables
var TankaKostnadVar = document.getElementById("tankaKostnad").value;
var TankaLiterVar = document.getElementById("tankaLiter").value;
var TankaDatumVar = document.getElementById("tankaDatum").value;
localStorage.setItem("StorageKostnadVar", JSON.stringify( [TankaKostnadVar] ));
localStorage.setItem("StorageLiterVar", JSON.stringify( [TankaLiterVar] ));
localStorage.setItem("StorageDatumVar", JSON.stringify( [TankaDatumVar] ));
//This is html page 2 (gets the items from localhost)
var TankaKostnadVar = localStorage.getItem("StorageKostnadVar");
var TankaLiterVar = localStorage.getItem("StorageLiterVar");
var TankaDatumVar = localStorage.getItem("StorageDatumVar");
var arrayKostnad = JSON.parse(TankaKostnadVar);
var arrayLiter = JSON.parse(TankaLiterVar);
var arrayDatum = JSON.parse(TankaDatumVar);
// Now you have arrays with data, but I don't know what you want to do with them...
// you could add more values like this (still page 2)...
arrayKostnad.push('new value 1')
arrayLiter.push('new value 2')
arrayDatum.push('new value 3')
localStorage.setItem("StorageKostnadVar", JSON.stringify( arrayKostnad ));
localStorage.setItem("StorageLiterVar", JSON.stringify( arrayLiter ));
localStorage.setItem("StorageDatumVar", JSON.stringify( arrayDatum ));
// now check the values again
var TankaKostnadArr = JSON.parse(localStorage.getItem("StorageKostnadVar"));
var TankaLiterArr = JSON.parse(localStorage.getItem("StorageLiterVar"));
var TankaDatumArr = JSON.parse(localStorage.getItem("StorageDatumVar"));
document.write(TankaKostnadArr, TankaLiterArr, TankaDatumArr)
And this is what I would do to clean things up a little...
// Import these functions and variables to any file that needs to interact with LocalStorage
var storageKeys = ["StorageKostnadVar","StorageLiterVar","StorageDatumVar"];
function addToArray(key, val, arrObj) {
arrObj[key].push(val)
}
function storeAllLocalStorage(arrayObject) {
Object.keys(arrayObject).forEach(key=>{
localStorage.setItem(key, JSON.stringify(arrayObject[key]));
})
}
// Use above functions when needed
var storedArrays = storageKeys.reduce((acc,key)=> {
var val = JSON.parse(localStorage.getItem(key));
if (typeof val === 'array') return {...acc, [key]:val};
return {...acc, [key]:[val]};
},{})
addToArray("StorageKostnadVar", document.getElementById("tankaKostnad").value, storedArrays);
addToArray("StorageLiterVar", document.getElementById("tankaLiter").value, storedArrays);
addToArray("StorageDatumVar", document.getElementById("tankaDatum").value, storedArrays);
storeAllLocalStorage(storedArrays)
You are simply using localStorage.setItem which saves your values with the given key. If the key exists, it will replace the value. Before you do a .setItem, get the value from the local storage first, then parse it to array so that you can finally push the new user inputs to that parsed array. Then you can .setItem to replace the "outdated" value from the localStorage.
UPDATE Example:
Sorry for leaving this hangin without an example. Here it is:
// Get array from local storage
const stringifiedArray = localStorage.getItem('myCollection');
// If there is no 'myCollection' from localStorage, make an empty array
const myCollection = stringifiedArray ? JSON.Parse(stringifiedArray) : [];
myCollection.push('My new item added'); // update array
localStorage.setItem('myCollection', JSON.stringify(myCollection)); // save
So, I have this function that, after an update, deletes elements from a table. The function, lets call it foo(), takes in one parameter.
foo(obj);
This object obj, has a subfield within called messages of type Array. So, it would appear something like this:
obj.messages = [...];
Additionally, inside of obj.messages, each element contains an object that has another subfield called id. So, this looks something like:
obj.messages = [{to:"You",from:"Me",id:"QWERTY12345.v1"}, ...];
Now, in addition to the parameter, I have a live table that is also being referenced by the function foo. It uses a dataTable element that I called oTable. I then grab the rows of oTable and copy them into an Array called theCurrentTable.
var theCurrentTable = oTable.$('tr').slice(0);
Now, where it gets tricky, is when I look into the Array theCurrentTable, I returned values appear like this.
theCurrentTable = ["tr#messagesTable-item-QWERTY12345_v1", ...];
The loop below shows how I tried to show the problem. While it works (seemingly), the function itself can have over 1000 messages, and this is an extremely costly function. All it is doing is checking to see if the current displayed table has the elements given in the parameter, and if not a particular element, delete it. How can I better write this function?
var theCurrentTable = oTable.$('tr').slice(0);
var theReceivedMessages = obj.messages.slice(0);
for(var idx = 0; idx < theCurrentTable.length; idx++){ // through display
var displayID = theCurrentTable[idx].id.replace('messagesTable-item-','').replace('_','.');
var deletionPending = true;
for(var x = 0; x < theReceivedMessages.length; x++){
var messageID = theReceivedMessages[x].id;
if(diplayID == messageID){
console.log(displayID+' is safe...');
deletionPending = false;
}
}
if(deletionPending){
oTable.fnDeleteRow(idx);
}
}
I think I understand your problem. Your <tr> elements have an id that should match an item id within your messages.
First you should extract the message id values you need from the obj parameter
var ids = obj.messages.map(function (m) { return '#messagesTable-item-' + m.id; });
This will give you all the rows ids you need to keep and then join the array together to use jQuery to select the rows you don't want and remove them.
$('tr').not(ids.join(',')).remove();
Note: The Array.prototype.map() function is only supported from IE9 so you may need to use jQuery.map().
You could create a Set of the message ID values you have, so you can later detect if a given ID is in this Set in constant time.
Here is how that would look:
var theCurrentTable = oTable.$('tr').slice(0);
var theReceivedMessages = obj.messages.slice(0);
// Pre-processing: create a set of message id values:
var ids = new Set(theReceivedMessages.map( msg => msg.id ));
theCurrentTable.forEach(function (row, idx) { // through display
var displayID = row.id.replace('messagesTable-item-','').replace('_','.');
// Now you can skip the inner loop and just test whether the Set has the ID:
if(!ids.has(displayId)) {
oTable.fnDeleteRow(idx);
}
});
So now the time complexity is not any more O(n.m) -- where n is number of messages, and m the number of table rows -- but O(n+m), which for large values of n and m can make quite a difference.
Notes:
If theCurrentTable is not a true Array, then you might need to use a for loop like you did, or else use Array.from(theCurrentTable, function ...)
Secondly, the implementation of oTable.fnDeleteRow might be that you need to delete the last rows first, so that idx still points to the original row number. In that case you should reverse the loop, starting from the end.
If i try to add more keys with values to a javascript object it alters the value of all keys, not just the one I have added.
var corridorObject = {};
var makeObjects = [];
function someFunction(){
var a = makePoints;
var Corridor = viewer.entities.add({
corridor : {
positions : (a),
width : 10.0,
material : Cesium.Color.GREEN,
}
var idv0 = Corridor.id
corridorObject[idv0] = makeObjects;
console.log(corridorObject);
makeObjects.length=0;
}
The Corridor ID is a guid, the makeObjects an array of objects, when I run this it adds the key perfectly, and the values, but when I run it a second time it adds a new key with the new ID and new values, but it also changes the values for all the other keys to the most recent values.
here is the console, as you can see the first time the array for the ID is 3 long the second time with the same id its 2 long
Object {91ff9967-7019-4e76-846e-c0e125481060: Array[3]}
Object {91ff9967-7019-4e76-846e-c0e125481060: Array[2], 3de2c2b1-5fb6-495c-9034-2b37713e5c30: Array[2]}
Sorry to be more clear, this is from Cesiumjs, its taking points and converting them to a corridor, the corridor id and an array of the points that made it are then added to this object. The array of points is then emptied.
If you are repeating
var corridorObject = {};
var makeObjects = [];
var idv0 = Corridor.id
corridorObject[idv0] = makeObjects;
console.log(corridorObject);
These line of code then It will initialise
var corridorObject = {};
Thats why you will get only one key. Put initialization outside of the iteration
I have this code, which works pretty well :
var draw = [
{lat:60.06484046010452,lng:-121.640625}, {lat:50.064191736659104,lng:-136.40625}, {lat:50.958426723359935,lng:-103.7109375}
];
But Now, as the Values of the Variable draw needs to be changed at the runtime, I Wrote this code & I expect it allow changing draw values as the Values of the variable st changes :
var st = "{lat:60.06484046010452,lng:-121.640625},{lat:50.064191736659104,lng:-136.40625},{lat:50.958426723359935,lng:-103.7109375}";
var draw =[ st ];
But this isn't working, How can i make it work, I'm a noob, thank you
st is of type String, you can only manipulate it as a text would be.
I believe you are using objects wrong but you were using it right initially:
var draw = [{lat:60.06484046010452,lng:-121.640625}, {lat:50.064191736659104,lng:-136.40625}, {lat:50.958426723359935,lng:-103.7109375}];
Furthermore if you need to add objects to this array use the push method.
draw.push({ lat: 60.06484046010452, lng: -103.7109375 });
To remove from the end use the pop method:
var lastItem = draw.pop();
To add at the beginning use the unshift method and to remove use shift.
You just turned your object into a string. Just keep it as an object, and it will work fine (a.k.a remove the quotes):
var st = '[{"lat":60.06484046010452,"lng":-121.640625},{"lat":50.064191736659104,"lng":-136.40625},{"lat":50.958426723359935,"lng":-103.7109375}]';
var draw = JSON.parse(st);
Your original code works and you can edit it. The draw variable will be a list of objects and you can add and delete items:
var draw = [
{lat:60.06484046010452,lng:-121.640625}, {lat:50.064191736659104,lng:-136.40625}, {lat:50.958426723359935,lng:-103.7109375}
];
draw.push({lat:10.10101010,lng:20.20202020});
for(var i = 0; i < draw.length; i++){
document.write(draw[i].lat + " / " + draw[i].lng + "<br/>");
}
I am experementing with javascript objects for the first time and need some help. I want to store generated user input in objects, push them into an array and later on reuse them. So far I have come to this:
function changeColors() {
//get the numbers from the html
var rd = parseInt(document.getElementById("red").value);
var gr = parseInt(document.getElementById("green").value);
var bl = parseInt(document.getElementById("blue").value);
var op = parseFloat(document.getElementById("opacity").value);
//convert the decimal into hexadecimal
var rdhex = (rd < 16) ? "0" + rd.toString(16) : rd.toString(16);
var grhex = (gr < 16) ? "0" + gr.toString(16) : gr.toString(16);
var blhex = (bl < 16) ? "0" + bl.toString(16) : bl.toString(16);
//concatenate all hex to generate a color
var hexcode = "#" + rdhex + grhex + blhex;
//view the change in the browser
document.getElementById("div").style.backgroundColor = hexcode;
document.getElementById("colordisplay").innerHTML = hexcode;
//change opacity
document.getElementById("div").style.opacity = op;
Here I get all the input that I need to store and in the next function I am trying to store it in an object and array:
function Save(){
var colors = {};
var nextColor = []
colors.nextColor = nextColor;
console.log(colors);
var rgb = document.getElementById("colordisplay").innerHTML;
var opacity = document.getElementById("div").style.opacity;
var name = document.getElementById("name").value;
var nextColor = {
"name": name,
"rgb": rgb,
"opacity": opacity
}
colors.nextColor.push(nextColor);
console.log(colors);
}
My question is: is how wrong is that and how it can be corrected?
Thank you!
I am unsure what your question exactly is, but looking at your code for Save I assume you're inquiring how to best store data in the context of an application. Looking at the Save-method body:
var colors = {};
var nextColor = [];
These variables are only available in the scope of the Save function. As such the "colors"-Object will only ever contain one single color Object, i.e. the "nextColor" Object created in the Save function. On top of this, the "colors"-Object is not accessible outside of the Save function, rendering it... well, useless.
Ideally you hold the contents of the "colors"-Object in a global variable (or reference it in another Object available to your application, i.e. a "Model") and fill the colors Object with the return of the Save-method, i.e.:
function Save() {
var rgb = document.getElementById("colordisplay").innerHTML;
var opacity = document.getElementById("div").style.opacity;
var name = document.getElementById("name").value;
var nextColor = {
"name": name,
"rgb": rgb,
"opacity": opacity
};
return nextColor;
}
// assume an event handler invoked after a form is submitted, this
// creates a nextColor and pushes it into the existing colors Object
function someEventHandler( e ) {
colors.nextColor.push( Save() );
}
This implies that the Save-methods sole function is to gather the values entered in the HTML document, and translate it into a new value Object. The Save-method now has no business knowing about any remaining data belonging to your application. (i.e. the creation of the "colors" Object and its "nextColor"-Array should be left to another function, ideally executed when your application launches).
I guess what I'm saying is you're on the right track, but you can get a lot of mileage by investing some time into creating separate functions to handle your data layer. After all, that's all JSON is, data.
If for instance you want to enter validation in your Save()-method (let's say to make sure that the "name" Input element actually contains a valid String), you just modify it there in that one function. If you additionally wish to make sure that the same color isn't added to the "nextColor"-Array twice, you can make another function that checks whether a color with the same values is already present in the data Object and either removes it or prevents pushing the duplicate value into the Array. This is logic that shouldn't be in the Save()-method, as such you can structure your program to organize your data neatly.
I hope this is the answer you were looking for.
Try this:
var colors = {
"nextColor": []
};
function Save() {
colors.nextColor.push({
"name": document.getElementById("name").value,
"rgb": document.getElementById("colordisplay").innerHTML,
"opacity": document.getElementById("div").style.opacity
});
console.log(colors);
}
Notice that the colors variable should be outside the scope of the function in order to retain the variable beyond individual runs of the Save() function.
I've also simplified the code quite a bit.