To change cursor to waiting in JavaScript, we set the body’s cursor style.
For instance, we write
document.body.style.cursor = "wait";
to set the body element’s cursor to 'wait' to show the loading the cursor.
Then we write
document.body.style.cursor = "default";
to set the body element’s cursor to 'default' to show the default cursor.
To add anchor jumping by using JavaScript, we use the scrollTo method.
For instance, we write
const jump = (h) => {
const top = document.getElementById(h).offsetTop;
window.scrollTo(0, top);
};
to define the jump function.
In it, we get the element with getElementById.
And we get the y coordinate of the target element with offsetTop.
Then we call window.scrollTo with 0 and top to scroll to the element.
To detect if a browser is blocking a popup with JavaScript, we check various property of the window.
For instance, we write
const newWin = window.open(url);
if (!newWin || newWin.closed || typeof newWin.closed === "undefined") {
//...
}
to call window.open to open url in a new window.
Then if newWin is undefined, or closed is true, or closed is undefined, then the popup window is blocked.
To disable an input type=text with JavaScript, we set the disabled or readOnly property.
For instance, we write
document.getElementById("foo").disabled = true;
or
document.getElementById("foo").readOnly = true;
to get the input with getElementById.
Then we disable the input by setting the disabled or readOnly property to true.
readOnly keeps the original input style when disabled.
disabled grays out the input when disabled.
To position a DIV in a specific coordinates with JavaScript, we set the left and top properties.
For instance, we write
const d = document.getElementById("yourDivId");
d.style.position = "absolute";
d.style.left = "10px";
d.style.top = "20px";
to select the element with getElementById.
We set its position to 'absolute'.
And then we set the left and top position to shift it horizontally and vertically.