When clicking on the button, i'll receive an email with the text "field1" and "field2". It should instead represent the value entered in num1 and num2. I'm pretty sure that the problem lies in the following line, but im not sure how to solve this issue:xhttp.send("num1=field1&num2=field2");
function calculate() {
var field1 = document.getElementById("num1").value;
var field2 = document.getElementById("num2").value;
var result = parseFloat(field1) * parseFloat(field2) - (995 * parseFloat(field1));
if (!isNaN(result)) {
document.getElementById("answer").innerHTML = "Savings in total: €" + result + ".00 excl. VAT";
}
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function () {
if (this.readyState == 4 && this.status == 200) {}
};
xhttp.open("POST", "php/calcA.php", true);
xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhttp.send("num1=field1&num2=field2");
}
Thanks in advance.
You send a string and not variables.
Instead of doing :
xhttp.send("num1=field1&num2=field2");
Do :
xhttp.send("num1="+field1+"&num2="+field2);
Related
i must send data of an objectstore with post to a php file but i can't transform objectstore to send it.
Thanks for help
var xhttp = new XMLHttpRequest();
xhttp.open("POST", "../php/sincDATI.php", true);
var request = indexedDB.open("rsapp",1, "persistent");
request.onsuccess = function (evt) {
var db = request.result;
var tx = db.transaction(pTable,"readwrite");
var store = tx.objectStore(pTable);
*** TRAFORM store in json ????
xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
};
};
xhttp.send(????);
};
I have found a solution for sending a JSON file, with an XMLHttpRequest transforming automatically an indexedDB objectStore:
function sendData(pTable,pMess) {
var xhttp = new XMLHttpRequest();
var sendArray=[];
var request = indexedDB.open("dbapp",1, "persistent");
request.onsuccess = function (evt) {
var db = request.result;
var tx = db.transaction(pTable,"readwrite");
var store = tx.objectStore(pTable);
var cursorRequest = store.getAll();
cursorRequest.onsuccess = function(event) {
var cursor=event.target.result;
for(var item of cursor) {
sendArray.push(item);
};
xhttp.open("POST", "../php/sincDATI.php", true);
xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
$("#lblMessaggi").html("OK!"+ xhttp.responseText);
};
};
xhttp.send("pArr="+JSON.stringify(sendArray));
};
};
};
why variable undefined and how put json data to global variable?
var responce;
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if(this.readyState == 4 && this.status === 200) {
responce = JSON.parse(xhttp.responseText);
console.log(responce.trainers);
}
}
xhttp.open("GET", "trainers.json", true);
xhttp.send();
console.log(responce); // undefined
The response variable will get a value when the onreadystatechange callback is fired... Until then... the variable is undefined...
U need to access it in the callback
I.e. put the console.log(response) in the callback...
xhttp.onreadystatechange = function() {
if(this.readyState == 4 && this.status === 200) {
responce = JSON.parse(xhttp.responseText);
console.log(responce); // Value will be defined at this point
console.log(responce.trainers);
}
}
How is it possible here to display next JSON data on intervals(20s for example)?
Here is the code for getting JSON data
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
var response = JSON.parse(xhttp.responseText);
var data= response.data;
var output = '';
for(var i = 0;i < data.length;i++){
output += ''+data[0].data1+''+data[0].data2+'<br/>';
}
document.getElementById('placeholder').innerHTML = output;
}
};
xhttp.open("GET", "url.json", true);
xhttp.send();
I have this code that displays JSON data. How could this code be remade to display random JSON data every 30 seconds?
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
var response = JSON.parse(xhttp.responseText);
var data= response.data;
var output = '';
for(var i = 0;i < data.length;i++){
output += ''+data[0].data1+''+data[0].data2+'<br/>';
}
document.getElementById('placeholder').innerHTML = output;
}
};
xhttp.open("GET", "url.json", true);
xhttp.send();
Here is an example of JSON
{
"data": [
{
"data":"John",
"data2": "Doe"
},
{
"data":"Nick",
"data2": "Doe"
},
]
}
How would it be best to use with setInterval, so that one minute "John Doe" is displayed, and other "Nick Doe"?
create a setInterval to call your logic every 30secs. Set index=0 initially and reset when it equals to your json's length.
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
var response = JSON.parse(xhttp.responseText);
var data= response.data;
var output = '';
var index = 0; // set your index
setInterval(function(){
if (index == data.length){
index= 0; // reset when equals json's length
}
output = ''+data[index].data1+''+data[index].data2+'<br/>';
document.getElementById('placeholder').innerHTML = output;
index++; // move to next element
},30000);
}
};
xhttp.open("GET", "url.json", true);
xhttp.send();
I have read online that the unexpected token issue can come from using JSON.parse().
I am getting this error Uncaught SyntaxError: Unexpected token u
What I am doing wrong?
My code look like this
var t=null;
var xmlhttp=new XMLHttpRequest();
xmlhttp.onreadystatechange=function(responseText)
{
if (xmlhttp.readyState == 4 &&xmlhttp.status==200)
var obj = JSON.parse(xmlhttp.responseText);
var str=JSON.stringify(obj);
var newArr = JSON.parse(str);
var len=newArr.length;
$.mobile.pageContainer.pagecontainer( "change","sales_home.html");
$(document).on('pageshow', "#temp", function (event, data) {
while (len > 0) {
len--;
}
});
}
xmlhttp.onerror=function(E)
{
alert("error"+ E);
}
xmlhttp.open("GET","url",true);
xmlhttp.send();
The problem becomes apparent if you indent the code consistently and correctly:
var t = null;
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function(responseText) {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200)
var obj = JSON.parse(xmlhttp.responseText);
var str = JSON.stringify(obj); // <====
var newArr = JSON.parse(str); // <====
var len = newArr.length;
$.mobile.pageContainer.pagecontainer("change", "sales_home.html");
$(document).on('pageshow', "#temp", function(event, data) {
while (len > 0) {
len--;
}
});
}
xmlhttp.onerror = function(E) {
alert("error" + E);
}
xmlhttp.open("GET", "url", true);
xmlhttp.send();
Note how the code does
var str = JSON.stringify(obj);
var newArr = JSON.parse(str);
no matter what the value of readyState and status are. That causes the error, because obj will be undefined, so JSON.stringify(obj) will return undefined, so JSON.parse will coerce that to the string "undefined", which it then cannot parse, failing on the first character, u.
You probably want to add a block:
var t = null;
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function(responseText) {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) { // Block starts here
var obj = JSON.parse(xmlhttp.responseText);
var str = JSON.stringify(obj);
var newArr = JSON.parse(str);
var len = newArr.length;
$.mobile.pageContainer.pagecontainer("change", "sales_home.html");
$(document).on('pageshow', "#temp", function(event, data) {
while (len > 0) {
len--;
}
});
} // Block ends here
}
xmlhttp.onerror = function(E) {
alert("error" + E);
}
xmlhttp.open("GET", "url", true);
xmlhttp.send();
Not quite following why you're parsing, then stringifying, then parsing again though... Or why you have an empty while loop...