如何在返回特定php会话变量响应时运行的js脚本中更改已定义的变量?
如果设置了特定的php会话变量,我将如何更改此canvas js数组中的颜色。我现在使用的方法导致了一个问题,即增加动画的速度,尽管颜色确实发生了变化。
<div id="isohold">
<canvas id="iso"></canvas>
<div id="loghold">Login</div>
</div>
<?php
session_start();
//3.1.4 if the user is logged in Greets the user with message
if (isset($_SESSION['userid'])){
$userid = $_SESSION['userid'];
echo " <script>
'use strict';
var rn = function rn(min, max) {
return Math.random() * (max - min) + min;
};
var ctx = iso.getContext('2d');
var _window = window;
var w = _window.innerWidth;
var h = _window.innerHeight;
var t = 10;
var arr = [];
var cn = 200;
var rad = 300;
var sp = rn(1, 5) / 10000;
iso.width = w;
iso.height = h;
while (~ ~ cn--) {
var angle = rn(110, 359);
arr = [].concat(arr, [{
color: 'rgba(81, 180, 200, 0.5)',
distortion: rn(15, 75),
tmod: rn(5, 10),
size: rn(15, 20),
speed: 0.0005,
angle: angle,
lastPos: {
x: w / 2,
y: h / 2
}
}]);
}
var draw = function draw() {
request = requestAnimationFrame(function () {
return draw();
});
t++;
ctx.globalCompositeOperation = 'source-over';
ctx.fillStyle = 'rgba(0, 0, 0,.1)';
ctx.fillRect(0, 0, w, h);
var crad = rad * Math.sin(300);
ctx.globalCompositeOperation = 'lighter';
arr.forEach(function (el) {
ctx.strokeStyle = el.color;
ctx.lineWidth = el.size;
ctx.beginPath();
var lastPos = el.angle - 0.0005;
var x = w / 2 + (crad + el.distortion * Math.sin(t / el.tmod)) * Math.cos(el.angle * 180 / Math.PI);
var y = h / 2 + (crad + el.distortion * Math.sin(t / el.tmod)) * Math.sin(el.angle * 180 / Math.PI);
ctx.moveTo(el.lastPos.x, el.lastPos.y);
ctx.lineTo(x, y);
el.lastPos = { x: x, y: y };
el.angle = (el.angle + 0.0005) % 359;
ctx.stroke();
});
};
var resize = function resize() {
iso.width = w = window.innerWidth;
iso.height = h = window.innerHeight;
};
var request = requestAnimationFrame(function () {
return draw();
});
window.addEventListener('resize', function () {
return resize();
});
</script>
<script>
$(\"#loghold\").hide();
</script>
";
}else{
echo "<script>
'use strict';
var rn = function rn(min, max) {
return Math.random() * (max - min) + min;
};
var ctx = iso.getContext('2d');
var _window = window;
var w = _window.innerWidth;
var h = _window.innerHeight;
var t = 10;
var arr = [];
var cn = 200;
var rad = 300;
iso.width = w;
iso.height = h;
while (~ ~ cn--) {
var angle = rn(110, 359);
arr = [].concat(arr, [{
color: 'rgba(255, 255, 255, 0.5)',
distortion: rn(15, 75),
tmod: rn(5, 10),
size: rn(15, 20),
speed: rn(1, 5) / 5000,
angle: angle,
lastPos: {
x: w / 2,
y: h / 2
}
}]);
}
var draw = function draw() {
request = requestAnimationFrame(function () {
return draw();
});
t++;
ctx.globalCompositeOperation = 'source-over';
ctx.fillStyle = 'rgba(0, 0, 0,.1)';
ctx.fillRect(0, 0, w, h);
var crad = rad * Math.sin(300);
ctx.globalCompositeOperation = 'lighter';
arr.forEach(function (el) {
ctx.strokeStyle = el.color;
ctx.lineWidth = el.size;
ctx.beginPath();
var lastPos = el.angle - el.speed;
var x = w / 2 + (crad + el.distortion * Math.sin(t / el.tmod)) * Math.cos(el.angle * 180 / Math.PI);
var y = h / 2 + (crad + el.distortion * Math.sin(t / el.tmod)) * Math.sin(el.angle * 180 / Math.PI);
ctx.moveTo(el.lastPos.x, el.lastPos.y);
ctx.lineTo(x, y);
el.lastPos = { x: x, y: y };
el.angle = (el.angle + el.speed) % 359;
ctx.stroke();
});
};
var resize = function resize() {
iso.width = w = window.innerWidth;
iso.height = h = window.innerHeight;
};
var request = requestAnimationFrame(function () {
return draw();
});
window.addEventListener('resize', function () {
return resize();
});
</script>
";
};
?>
答案 0 :(得分:1)
<?php $color="yellow"; ?> <!--define it in php-->
<div id="color" data-color= <?php echo $color; ?> ></div> <!--insert it in html-->
<script>
var color=""; //declare your variable in JS
window.onload = function(e) {
color=document.getElementById("color").dataset.color; //redefine the variable's value from the html defined by the php
};
</script>