I've tried several answers posted in the site like:
How to check if JSON return is empty with jquery
And no one is working for me.
xhr.onload = function(){
detalles = xhr.responseText;
console.log("log : "+detalles);
....
}
Console output:
log : [0]
Firefox debugger network tab shows JSON 0: 0
Any help provided will be much appreciated.
EDIT - Adding some more code to extend the context
xhr.onload = function(){
detalles = xhr.responseText;
console.log(detalles);
if((!$.trim(detalles))||($.isEmptyObject(detalles))||(!detalles[0])){
console.log("ok");
$("#graficohist").html("No info available");
triggerLoader();
}
You can simply make a function to test in the object is empty
var myObj = {"key" : "value"};
checkEmptyJson = function(myObj){
var count = 0;
for(var key in myObj){
count++;
break;
}
if(count == 0){
return false; // object is empty
}else{
return true; // object is not empty
}
}
var result = checkEmptyJson(myObj);
console.log(result);
In your context we can use it as
hasDetallesData = checkEmptyJson(detalles); // true if Detalles has data
I suggest to try this
var obj = JSON.parse(text);
to convert your json to a javascript object, and then you can make a print it with
console.log(obj)
to see what you have inside the obj
Related
EXPLANATION
So from PHP to JavaScript encoded JSON array is sent in following:
$qa = array('question' => $question, 'a1' => $answer1, 'a2' => $answer2, 'a3' => $answer3);
echo json_encode($qa, JSON_UNESCAPED_UNICODE);
In JavaScript when I'm using like this (take a look at drawOutput):
function getSuccessOutput() {
getRequest(
't.php', // demo-only URL
drawOutput,
drawError
);
return false;
}
function drawOutput(responseText) {
var container = document.getElementById('output');
container.innerHTML = responseText;
}
function getRequest(url, success, error) {
var req = false;
try{
// most browsers
req = new XMLHttpRequest();
} catch (e){
// IE
try{
req = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
// try an older version
try{
req = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e){
return false;
}
}
}
if (!req) return false;
if (typeof success != 'function') success = function () {};
if (typeof error!= 'function') error = function () {};
req.onreadystatechange = function(){
if(req .readyState == 4){
return req.status === 200 ?
success(req.responseText) : error(req.status)
;
}
}
req.open("GET", url, true);
req.send(null);
return req;
}
I got following output:
{"question":"This is my question?","a1":"answer1","a2":"answer2","a3":"answer3"}
DESIRED RESULTS
I need extract each value from this array and assign to variables, example:
var myQuestion = "This is my question?";
var answ1 = "answer1";
var answ2 = "answer2";
var answ3 = "answer3";
WHAT I'VE TRIED
function drawOutput(responseText) {
var container = document.getElementById('output');
container.innerHTML = responseText;
// OUTPUT: {"question":"This is my question?","a1":"answer1","a2":"answer2","a3":"answer3"}
container.innerHTML = responseText[0];
// OUTPUT: <
container.innerHTML = responseText[a1];
// OUTPUT: nothing (blank)
}
Also I've tried:
function drawOutput(responseText) {
$.getJSON("t.php", function(responseText){
var container = document.getElementById('output');
var theObject = JSON.parse(responseText);
container.innerHTML = theObject[a1];
});
}
// OUTPUT: nothing (blank)
Also I've tried to use var theObject = JSON.parse(JSON.stringify(responseText)); instead of var theObject = JSON.parse(responseText); in this case output: undefined
If I'm using in following:
function drawOutput(responseText) {
var container = document.getElementById('output');
var theObject = JSON.parse(responseText);
container.innerHTML = theObject[a1];
}
// Output: nothing (blank)
But I got an error in browser's console: SCRIPT1014: Invalid character
I've read many similar issues, but nothing helped in my case. Have you any ideas, how could I solve It?
UPDATE
That's what I'm trying now and have nothing as output (blank):
function drawOutput(responseText) {
$.getJSON("t.php", function(responseText){
var question = theObject.question; // Get the question
var a1 = theObject.a1; // Get the answers
var a2 = theObject.a2;
var a3 = theObject.a3;
var container = document.getElementById('output');
container.innerHTML = a1;
alert(a1);
});
}
Parsing it is correct. If you get the text via XMLHttpRequest, you'll need to use JSON.parse on responseText. If you use jQuery's $.getJSON, it will do it for you and give you the parsed result.
The problem is how you're trying to access the values from the result. In theObject[a1], you're trying to use a variable called a1, whose value will then be used as the name of the property to get. Instead, use theObject.a1 or theObject["a1"].
So here, where you're using getJSON and so it's already been parsed for you:
function drawOutput() {
$.getJSON("t.php", function(theObject){ // Note: Not `responseText`, a parsed object
var question = theObject.question; // Get the question
var a1 = theObject.a1; // Get the answers
var a2 = theObject.a2;
var a3 = theObject.a3;
// ...use them...
});
}
Side note: Instead of separate a1,a2, anda3` properties on the object you're returning, you might consider using an array.
$qa = array(
'question' => $question,
'answers' => array($answer1, $answer2, $answer3)
);
echo json_encode($qa);
then
function drawOutput() {
$.getJSON("t.php", function(theObject){
var question = theObject.question; // Get the question
var answers = theObject.answers; // Get the answers
// ...use question, and `answers[0]` through `answers[2]`, where
// you can get the number of answers from `answers.length`...
});
}
You can access object values with one of these method:
var responseText = '{"question":"This is my question?","a1":"answer1","a2":"answer2","a3":"answer3"} ';
var theObject = JSON.parse(responseText);
console.log(theObject['a1']); // a1 in string
console.log(theObject.a1); // Gives the same result
In PHP you need to json_encode your response :
$ServerResponse= json_encode($MyJSON);
In Javascript you need to JSON.parse the response you got from PHP :
var myJSONObject = JSON.parse(ServerResponse);
After that , you have a normal Object in your hands , and that is myJsonObject. You can access its properties either with the use of "dot" (Eg. myJsonObject.PROPERTY_NAME) or with brackets (Eg myJsonObject["PROPERTY_NAME"]).
I am making an ajax call in my javascript submit function. In this ajax call, I am passing an array(globalSelection) as data to the servlet. This array consists elements of function textSelection which is also pasted below.
globalSelection =[];
function submit() {
console.log("globalSelection start")
console.log(globalSelection)
console.log("globalSelection end")
$.ajax({
async : false,
type : "POST",
url : 'http://example.com:8080/myApp/DataServlet',
data: {globalSelection:globalSelection},
success : function(data) {
alert(data)
},
error : function(data, status, er) {
alert("error: " + data + " status: " + status + " er:" + er);
}
});
}
function textSelection(range, anchorNode, focusNode) {
this.range = range;
this.type = 3;
this.rCollection = [];
this.textContent = encodeURI(range.toString());
this.anchorNode = anchorNode;
this.focusNode = focusNode;
this.selectionId = getRandom();
this.yPOS = getYPOS();
this.getTagName = function(range) {
var el = range.startContainer.parentNode;
return el;
}
this.getTagIndex = function(el) {
var index = $(el.tagName).index(el);
return index;
}
this.simpleText = function(node, range) {
if (!node)
var entry = this.createEntry(this.anchorNode, this.range);
else
var entry = this.createEntry(node, range);
this.rCollection.push(entry);
this.highlight(this.rCollection[0].range);
this.crossIndexCalc();
textSelection._t_list.push(this);
pushto_G_FactualEntry(this);
}
this.compositeText = function() {
this.findSelectionDirection();
var flag = this.splitRanges(this.anchorNode, this.focusNode,
this.range.startOffset, this.range.endOffset);
if (flag == 0) {
for (j in this.rCollection) {
this.highlight(this.rCollection[j].range);
}
}
this.crossIndexCalc();
textSelection._t_list.push(this);
pushto_G_FactualEntry(this);
}
}
I am ading the screen of my browser console below, which prints the globalSelection(array).
In my servlet I am getting this array as follows
String[] arrays = request.getParameterValues("globalSelection[]");
System.out.println(arrays);
Here I am getting null value for arrays.
If I put globalSelection as follows in submit function for simple test to servlet, I am able to get the arrays.
var globalSelection = ["lynk_url", "jsonBody", "lynk_dummy1", "lynk_dummy2", "lynk_name", "lynk_desc", "lynk_flag"];
Why my actual globalSelection is shows null in servlet, what I am doing wrong here.
Try with :
String[] arrays = request.getParameterValues("globalSelection");
System.out.println(arrays);
Because the parameter submitted with name "globalSelection" only not "[]" symbol.
I see your problem and I have a simple solution.
I recommend in that case that you convert the array as a string in JS:
JSON.stringify(globalSelection)
and then reconstructing the object on the backend using some sort of library for JSON conversion like: https://code.google.com/archive/p/json-simple/
You could then do something like this:
JSONArray globalSelection = (JSONArray) new JSONParser().parse(request.getParameter("globalSelection"));
Iterator i = globalSelection.iterator();
while (i.hasNext()) {
JSONObject selection = (JSONObject) i.next();
String type = (String)selection.get("type");
System.out.println(type);
}
This will parse your array and print the selection type. Try it, hope it helps.
I have a function that is supposed to check old data against data. I am parsing data and oldData to get a JSON object respectively as dbData and formData are simply strings containing ID's and values for the HTMML form. The purpuse of the function is to check if the user has made any textchanges some textareas in the HTML form. I want to do this by checking the ID for each textarea and then check if the value in formData and Data are the same. In that case no change has been made and the function will return true.
The data string im parsing looks something like this:
"[{\"texts\":[{\"default\":true,\"bread-texts\":false,\"textarea1\":\"Banana\",\"textarea2\":\"Kiwi\",\"textarea3\":\Apple \",\"textarea4\":\"coffe\",\"textarea5\":\"Tea\",\"signature\":true,\"profile\":\"header\",\"fontsize\":\"26\",\"fontsize-headers\":\"10.5\",\"fontcolor\":\"#0000\",\"textfont\":\"header-large\",\"textsub1\":\"Bold\",\"font\":\"ICA%20Text\",\"textsub\":\"Regular\",\"textsize\":\"20\",\"textsize-signature\":\"9.5\",\"textsizesmall\":\"5.5\",\"textsizesmall-placer\":\"2.75\",\"vers-placer\":\"false\",\"text-colored\":\"%23000000\",\"s-all-customers\":true,\"new-customers\":true,\"undefined\":\"\"}]}]"
So for example, i have to check the ID for "textarea1" in dbData and formData and then check if the value is the same. Can this be done using wildcard or is there a better way to archive this?
function CheckValues() {
var isChanged = false;
var formData = $.parseJSON(data);
var dbData = $.parseJSON(oldData);
if(formData !== dbData) {
var isChanged = true;
}
return isChanged;
}
The code shown below works in IE9+, Chrome, FireFox but other
browsers yet to test. The example shows two different values, data and
OldData - data contains "Tea" where as OldData contains "OldTea" so
isChanged flag is true.
function CheckValues() {
var data = "{\"disable\":false,\"textarea1
\":\"Banana\",\"textarea2\":\"Kiwi\",\"textarea3
\":\"Milk\",\"textarea4\":\"Coffe\",\"textarea5\":\"Tea\"}";
var oldData = "{\"disable\":false,\"textarea1
\":\"Banana\",\"textarea2\":\"Kiwi\",\"textarea3
\":\"Milk\",\"textarea4\":\"Coffe\",\"textarea5\":\"OldTea\"}";
var formData = JSON.parse(data);
var dbData = JSON.parse(oldData);
var oFormData = Object.keys(formData);
var oDbData = Object.keys(dbData);
var isChanged = false;
if (oFormData.length === oDbData.length)
{
for (var i = 0; i < oFormData.length; i++) {
var propName = oFormData[i];
if (typeof (dbData[propName]) === "undefined") {
isChanged = true;
break;
}
else {
if (formData[propName] !== dbData[propName]) {
isChanged = true;
break;
}
}
}
}
}
I am trying to parse a json object and try to do an alert in js if a particular word is detected in the json string,
CloudPush.addEventListener('callback', function (evt) {
//alert(evt);
alert(evt.payload);
var jsonNotification = JSON.parse(evt.payload);
for (var i = 0; i < jsonNotification.length; i++) {
var text = new String(jsonNotification[i]);
if (text == 'Hello') {
alert('Hello');
}else{
alert('Error');
}
}
I am however getting some errors that the alert 'Hello' does not display. Not really sure if I am doing it correctly. Hopefully someone can shed some light.
CloudPush.addEventListener('callback',
function (evt) {
// parse the desired data
var data= JSON.parse(evt.payload),
key;
// loop over all the keys of the JSON object
for (key in data) {
if(data.hasOwnProperty(key)){
alert( data[key] === 'Hello' ? 'Hello' : 'Error' );
}
}
);
I have been trying to figure this out for the past week and everything that i try just doesn't seem to work.
I have to create a web service on my local box that responds to requests. The client (that i did not write) will ask my service one question at a time, to which my server should respond with an appropriate answer.
So the last thing i have to do is:
When a POST request is made at location '/sort' with parameter 'theArray', sort the array removing all non-string values and return the resulting value as JSON.
theArray parameter will be a stringified JSON Array
From going through trail and error i have found out that the parameters supplied is:
{"theArray":"[[],\"d\",\"B\",{},\"b\",12,\"A\",\"c\"]"}
I have tried many different thing to try to get this to work. But the closest thing i can get is it only returning the same thing or nothing at all. This is the code that i am using to get those results:
case '/sort':
if (req.method == 'POST') {
res.writeHead(200,{
'Content-Type': 'application/json',
'Access-Control-Allow-Origin': '*'
});
var fullArr = "";
req.on('data', function(chunk) {
fullArr += chunk;
});
req.on('end', function() {
var query = qs.parse(fullArr);
var strin = qs.stringify(query.theArray)
var jArr = JSON.parse(fullArr);
console.log(jArr); // Returns undefided:1
var par = query.theArray;
console.log(par); // returns [[],"d","B",{},"b",12,"A","c"]
function censor(key) {
if (typeof key == "string") {
return key;
}
return undefined;
}
var jsonString = JSON.stringify(par, censor);
console.log(jsonString); // returns ""
});
res.end();
};
break;
Just to clarify what I need it to return is ["d","B","b","A","c"]
So if someone can please help me with this and if possible responded with some written code that is kinda set up in a way that would already work with the way i have my code set up that would be great! Thanks
Edit: Try this:
var query = {"theArray":"[[],\"d\",\"B\",{},\"b\",12,\"A\",\"c\"]"};
var par = JSON.parse(query.theArray);
var stringArray = [];
for ( var i = 0; i < par.length; i++ ) {
if ( typeof par[i] == "string" ) {
stringArray.push(par[i]);
}
}
var jsonString = JSON.stringify( stringArray );
console.log(jsonString);
P.S. I didnt't pay attention. Your array was actually a string. Andrey, thanks for the tip.
The replacer parameter of JSON.stringify doesn't work quite like you're using it; check out the documentation on MDN.
You could use Array.prototype.filter to filter out the elements you don't want:
var arr = [[],"d","B",{},"b",12,"A","c"];
arr = arr.filter(function(v) { return typeof v == 'string'; });
arr // => ["d", "B", "b", "A", "c"]
edit: one-liner (try it in repl!)
JSON.stringify(JSON.parse(require('querystring').parse('theArray=%5B%5B%5D%2C"d"%2C"B"%2C%7B%7D%2C"b"%2C12%2C"A"%2C"c"%5D').theArray).filter(function(el) {return typeof(el) == 'string'}));
code to paste to your server:
case '/sort':
if (req.method == 'POST') {
buff = '';
req.on('data', function(chunk) { buff += chunk.toString() });
res.on('end', function() {
var inputJsonAsString = qs.parse(fullArr).theArray;
// fullArr is x-www-form-urlencoded string and NOT a valid json (thus undefined returned from JSON.parse)
var inputJson = JSON.parse(inputJsonAsString);
var stringsArr = inputJson.filter(function(el) {return typeof(el) == 'string'});
res.writeHead(200,{
'Content-Type': 'application/json',
'Access-Control-Allow-Origin': '*'
});
res.end(JSON.stringify(stringsArr));
};
break;