Every tree node is an object.… Other node types.There are some other node types besides elements and text nodes.… type – comment node, labeled as #comment, between two text nodes.… There are 12 node types.… Tags become element nodes and form the structure.
Text becomes text nodes.
The browser tries to help us by mixing namespaces of JS and DOM.… Also, when one reads JS code and doesn’t have HTML in view, it’s not obvious where the variable comes… getElementsBy*.There are also other methods to look for nodes… Summary.There are 6 main methods to search for nodes in DOM:
Method
Searches by...
Let’s get a more in-depth look at DOM nodes.… DOM node classes.Different DOM nodes may have different properties.… Text nodes are not the same as element nodes.… Node – is also an “abstract” class, serving as a base for DOM nodes.… Main DOM node properties are:
nodeType
We can use it to see if a node is a text or an element node.
All DOM nodes generate such signals (but events are not limited to DOM).… HTML:
HTML + JS
nodes or strings at the beginning of node,
node.before(...nodes or strings) –- insert nodes or strings… before node,
node.after(...nodes or strings) –- insert nodes or strings after node,
node.replaceWith… (...nodes or strings) –- replaces node with the given nodes or strings.… parentElem.removeChild(node)
Removes node from parentElem (assuming node is its child).… right before node,
node.after(...nodes or strings) –- insert right after node,
node.replaceWith(...nodes
Set range start:
setStart(node, offset) set start at: position offset in node
setStartBefore(node) set… start at: right before node
setStartAfter(node) set start at: right after node
Set range end (similar… methods):
setEnd(node, offset) set end at: position offset in node
setEndBefore(node) set end at: right… before node
setEndAfter(node) set end at: right after node
Technically, setStart/setEnd can do anything… In all these methods, node can be both a text or element node: for text nodes offset skips that many
From it we can access any node.… That’s the DOM node of the <html> tag.… The childNodes collection lists all child nodes, including text nodes.… For instance, in childNodes we can see both text nodes, element nodes, and even comment nodes if they… But for many tasks we don’t want text or comment nodes.
boolean options “what kind of changes to react on”:
childList – changes in the direct children of node… ,
subtree – in all descendants of node,
attributes – attributes of node,
attributeFilter – an array of… "attributes": attribute modified
"characterData": data modified, used for text nodes… Garbage collection interaction
Observers use weak references to nodes internally.… The mere fact that a DOM node is observed doesn’t prevent the garbage collection.
this:
In the code above:
We load 1.js… , then if there’s no error…
We load 2.js, then if there’s no error…
We load 3.js, then if there’s no… --
loadScript('1.js', function(error, script) {
if (error) {
handleError(error);
} else {… loadScript('2.js', function(error, script) {
if (error) {
handleError(error);
} else… loadScript('3.js', function(error, script) {
if (error) {
handleError(error);
We could try to analyze the element content and dynamically copy-rearrange DOM nodes.… But the nodes in the document are actually not moved around!… It gets all nodes from the light DOM that aren’t slotted elsewhere.… Composition does not really move nodes, from JavaScript point of view the DOM is still same.… the slot.
node.assignedSlot – the reverse property, returns slot by a node.
template content is available in its content property as a DocumentFragment – a special type of DOM node… We can treat it as any other DOM node, except one special property: when we insert it somewhere, its
Code minifiers (tools used before JS gets to production, to compress it) rename local variables into
For element nodes, most standard HTML attributes automatically become properties of DOM objects.… DOM nodes are regular JavaScript objects. We can alter them.
Two interesting polyfill libraries are:
core js that supports a lot, allows to include only needed features
For server-side environments (like Node.js), you can execute the script with a command like "node
They work like this:
We register at the service and get a piece of JS (or a script URL) from them to… That JS script sets a custom window.onerror function.
admin object:
As you can see, when 1.js… changes the name property in the imported admin, then 2.js can see the new admin.name.
--
```js
function pow(x, n) {
let result = 1;
for (let i = 0; i < n; i++) {
result *= x;
}
For instance, a root element of our own JS-based menu may trigger events telling what happens with the
For JS-code it means that we should check if (event.ctrlKey || event.metaKey).
Kotlin is a modern, concise and safe programming language that can target the browser or Node.
For server-side JS that’s clearly noticeable, and if you are running it in-browser, then try to click
So, if we want to get an object with name/value pairs, we need to throw in a bit JS.
Each event may be useful:
DOMContentLoaded event – DOM is ready, so the handler can lookup DOM nodes
--
```js
let phrase = "Hello";
function say(name) {
alert( `${phrase}, ${name}` );