How to read a firebase Data using HTML5 and Javascript?
Question
When I want to read the data of my Firebase, nothing appears.
I have tried to read the data using a script for this.
This is my HTML code:
<html>
<head>
<title>Javascript Firebase</title>
Humidity: <humidity></humidity><br>
Clock: <clock></clock><br>
</head>
<body>
and this is my script:
<script type="text/javascript">
var database = firebase.database('javascript-firebase-6567d');
var h document.querySelector('humidity');
var c = document.querySelector('clock');
var pad = function(x){
return x < 10 ? '0' +x : x;
}
var ShowClock = function() {
var d = new Date();
var h = pad(d.getHours());
var m = pad (d.getMinutes());
var s = pad (d.getSeconds());
c.innerHTML = [h,m,s].join(':');
}
setInterval(ShowClock,1000);
var myRef = Firebase('https://javascript-firebase-6567d.firebaseio.com/rooms');
myRef.on('child_changed',function(snapshot){
data = snapshot.val();
h.innerHTML = data.humidity;
});
</script>
The results that I hope is to see the changes that the child "humidity" shows but currently I can not see the results of the clock or the humidity
1 answers
solution1
0 ACCPTED 2019-04-20 04:11:53
This code:
myRef.on('child_changed',function(snapshot){
data = snapshot.val();
h.innerHTML = data.humidity;
});
The child_changed event only fires when the data in the location changes . If you're trying to show the current child nodes under a location, you'll want to use child_added :
myRef.on('child_added',function(snapshot){
data = snapshot.val();
console.log(data);
});
The child_added fires immediately after attaching the listener for any existing child node, and then subsequently for any new nodes that are added.
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