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73 lines
2.2 KiB
Plaintext
73 lines
2.2 KiB
Plaintext
---
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id: element-properties
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title: Element attributes and properties
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---
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import Admonition from "../components/Admonition"
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import Accordion from "../components/Accordion"
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import InternalLink from "../components/InternalLink"
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import MDN from "../components/MDNBadge"
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### 1. tagName
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`Element.tagName : string`
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`.tagName` is a read-only property on any element, which returns the tag name in uppercase form. This is useful to identify type of a element.
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Ex. For a `<div/>` element, tagName is `"DIV"`.
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```js
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ele = document.querySelector("img");
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ele.tagName // "IMG"
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```
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:::note Text nodes don't have `tagName`
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Text nodes are not element, so they don't have any tagName.
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To identify the type of node, use `.nodeType` - which returns `3` (same as `Node.TEXT_NODE`) for text nodes.
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<MDN title="nodeType" url="https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeType" />
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:::
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## Children
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:::note Types of Children
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All elements will *generally* have 2 types of children - 1. element and 2. text node.
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You can think of elements as other tags and text node as the text within a tag.
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```jsx
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<div>
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This is // <- 1. text node
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<span> // <- 2. element
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some text // 2.1. <span> contains text node
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</span>
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</div>
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```
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If you recall, *Element* extends from *Node* - so all elements are nodes. That means, every child is technically a node.
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This is important because some properties return **only child elements**, whereas others return **all child nodes** (both element and text node). For ex, `ele.childNodes` returns all child nodes, but `ele.children` returns only child elements.
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**Always use the one which is more suitable for your case**. Remember, even if you haven't added any "text" between a tag, it can still have **invisible text nodes** due to spaces and newline characters.
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```jsx
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<div id="container">
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<div></div>
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</div>
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container.childNodes // [text, div, text]
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// extra text nodes contain newline and space
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```
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Read more about [other types of nodes](https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeType) and how [whitespace works in html](https://developer.mozilla.org/en-US/docs/Web/API/Document_Object_Model/Whitespace).
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:::
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<!-- ## Content - html, text
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## Traversal (and ientification)
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## Attribute, class, id, data
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## Scroll -->
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