# HTML5/BS

* [Chrome](#chrome)
* [Percent-encoding reserved](#percent-encoding-reserved)
* [HTML5](#html5)
  * [lang](#lang)
  * [Subresource Integrity](#subresource-integrity)
* [media type](#media-type)
* [icons](#icons)
* [Events](#events)
* [CSS box model](#css-box-model)
  * [box-sizing](#box-sizing)
  * [content](#content)
  * [padding](#padding)
  * [border](#border)
  * [margin](#margin)
* [Spacing](#spacing)
* [Mobile](#mobile)
* [Flexbox](#flexbox)
* [UI Frameworks](#ui-frameworks)
* [Bootstrap](#bootstrap)
  * [Version 3](#version-3)
  * [Version 4](#version-4)
  * [Version 5](#version-5)
  * [Grid system](#grid-system)
  * [forms](#forms)
* [whitespace and wrap](#whitespace-and-wrap)
* [robots](#robots)
* [Frameworks](#frameworks)

## Chrome

```
hard reload: Ctrl + F5
F12 -> Ctrl+Shift+P -> "screenshot"
delete address history: Shift + Del
remove domain name: F12 -> console
    document.body.innerHTML = document.body.innerHTML.replace(/\.\w+\.\w+(?=:)/g, "")
```

## Percent-encoding reserved

https://en.wikipedia.org/wiki/Percent-encoding

| !   | #   | $   | %   | &   | '   | (   | )   | \*  | +   | ,   | /   | :   | ;   | =   | ?   | @   | \[  | ]   |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| %21 | %23 | %24 | %25 | %26 | %27 | %28 | %29 | %2A | %2B | %2C | %2F | %3A | %3B | %3D | %3F | %40 | %5B | %5D |

## HTML5

https://www.w3.org/TR/html5\
https://developer.mozilla.org/en-US/docs/Web/HTML/Element

### lang

empty string indicates that the primary language is unknown

https://www.w3.org/TR/html5/dom.html#the-lang-and-xml:lang-attributes\
http://www.ietf.org/rfc/bcp/bcp47.txt

### Subresource Integrity

https://www.w3.org/TR/SRI/#resource-integrity

## media type

MIME type or content type: http://www.iana.org/assignments/media-types/media-types.xhtml#application

```
application/pdf
audio
font
example
image
message
model
multipart
text
video
```

## icons

https://github.com/encharm/Font-Awesome-SVG-PNG/tree/master/white/svg

## Events

https://developer.mozilla.org/en-US/docs/Web/Events

```
cut/copy/paste  
input: the value of an <input>, <select>, or <textarea> element is changed  
ValueChange: mainly for an accessibility purpose, e.g.: <progress>  
change(Firefox OS specific, any change made to a file inside a given storage area)
```

## CSS box model

https://developer.mozilla.org/en-US/docs/Web/CSS/CSS\_Box\_Model/Introduction\_to\_the\_CSS\_box\_model\
Every box is composed of four parts (or areas), defined by their respective edges.\
![](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Box_Model/Introduction_to_the_CSS_box_model/boxmodel.png)

### box-sizing

https://developer.mozilla.org/en-US/docs/Web/CSS/box-sizing

`content-box` is the default.\
`border-box` tells the browser to account for any border and padding in the value you specify for width and height.

### content

"real" content of the element

size can be explicitly defined with the width, min-width, max-width, height, min-height, and max-height properties.

When the content area has a background, it extends into the padding.

### padding

extends the content area to include the element's padding.

```
dimensions: padding-box width/height
thickness: padding[-top/right/bottomleft]
```

### border

extends the padding area to include the element's borders.

```
dimensions: border-box width/height
thickness: border[-width]
```

If the box-sizing property is set to border-box, the border area's size can be explicitly defined with the width, min-width, max-width, height, min-height, and max-height properties.

### margin

extends the border area to include an empty area used to separate the element from its neighbors.

```
dimensions: margin-box width/height
size: margin[-top/right/bottomleft]
```

When margin collapsing occurs, the margin area is not clearly defined since margins are shared between boxes.\
https://developer.mozilla.org/en/CSS/margin\_collapsing

## Spacing

https://getbootstrap.com/docs/4.0/utilities/spacing/

```
Examples: class="mx-auto / pt-3"

{property}{sides}-{size} for xs
{property}{sides}-{sm, md, lg, xl}-{size}

m - margin
p - padding

t - top
b - bottom
l - left
r - right
x - *-left and *-right
y - *-top and *-bottom
blank - all 4 sides

0 - 0
1 -$spacer * .25
2 -$spacer * .5
3 -$spacer
4 -$spacer * 1.5
5 -$spacer * 3
auto - margin auto
```

## Mobile

https://developer.mozilla.org/en-US/docs/Mozilla/Mobile/Viewport\_meta\_tag

```
viewport: a virtual "window"
viewport meta tag: let web developers control the viewport's size and scale.
```

https://developer.apple.com/library/content/documentation/AppleApplications/Reference/SafariHTMLRef/Articles/MetaTags.html#//apple\_ref/doc/uid/TP40008193

```
initial-scale: The default is calculated to fit the webpage in the visible area.
maximum-scale:  The default is 5.0. The range is from >0 to 10.0.
user-scalable: whether or not the user can zoom in and out. yes
shrink-to-fit=no: override  "width=device-width" to prevent the page from scaling
    <meta name="viewport" content="width=device-width, initial-scale=1.0, shrink-to-fit=no">
```

## Flexbox

* Game: https://flexboxfroggy.com/
* Doc: https://developer.mozilla.org/en-US/docs/Learn/CSS/CSS\_layout/Flexbox ![](https://developer.mozilla.org/en-US/docs/Learn/CSS/CSS_layout/Flexbox/flex_terms.png)

Click links to live try:

* `flex-direction`: specifies which direction the **main axis** runs; `column` -> vertically
* `flex-wrap`: default `nowrap`
* `flex-flow` = `flex-direction` + `flex-wrap`
* [`justify-content`](https://developer.mozilla.org/en-US/docs/Web/CSS/justify-content#examples): default `flex-start`, items sit at the start of the main axis
* [`align-items`](https://developer.mozilla.org/en-US/docs/Web/CSS/align-items#examples)：default `stretch`，fill the parent in the direction of the cross axis
* [`align-content`](https://developer.mozilla.org/en-US/docs/Web/CSS/align-content#formal_syntax)：around content items along a flexbox's cross-axis
* [`flex`](https://developer.mozilla.org/en-US/docs/Web/CSS/flex#examples): grow or shrink to fit the space | flex-grow + flex-shrink + flex-basis

## UI Frameworks

https://github.com/stars/fzinfz/lists/frontend

## Bootstrap

### Version 3

https://getbootstrap.com/docs/3.3/getting-started/#download-cdn

### Version 4

https://v4-alpha.getbootstrap.com/getting-started/introduction/#starter-template

http://blog.getbootstrap.com/2017/08/10/bootstrap-4-beta/

* compiles faster than ever thanks to Libsass
* moved nearly everything to flexbox, added a new grid tier to better target mobile devices, and completely overhauled our source Sass with better variables, mixins, and now maps, too.
* https://getbootstrap.com/docs/4.0/components/card/
* move gradients, transitions, shadows, grid classes, and more into Sass variables.
* drop support for IE8/IE9, Safari 8-, iOS 8-, etc
* JS plugins in ES6. new teardown methods, option type checking, new methods, and more.
* auto-placement of tooltips, popovers, and dropdowns from https://popper.js.org
* npm scripts instead of Grunt

### Version 5

https://blog.getbootstrap.com/2021/05/05/bootstrap-5/

```
No more jQuery!
Dropped Internet Explorer 10 and 11
Dropped Microsoft Edge < 16 (Legacy Edge)
Dropped Firefox < 60
Dropped Safari < 12
Dropped iOS Safari < 12
Dropped Chrome < 60
```

### Grid system

https://getbootstrap.com/docs/3.3/css/#grid

Rows must be placed within a .container\[-fluid] for proper alignment and padding. Columns create gutters (gaps between column content) via `padding`. That padding is offset in rows for the first and last column via negative margin on `.rows`.

### forms

https://getbootstrap.com/docs/4.0/components/forms/#form-groups

.form-group provides a flexible class that encourages proper grouping of labels, controls, optional help text, and form validation messaging.

.row for .form-row, a variation of our standard grid row that overrides the default column gutters for tighter and more compact layouts.

https://getbootstrap.com/docs/4.3/components/forms/#inline-forms

.form-inline class to display a series of labels, form controls, and buttons on a single horizontal row.

## whitespace and wrap

https://css-tricks.com/almanac/properties/w/whitespace/

|          | New lines | Spaces and tabs | Text wrapping |
| -------- | --------- | --------------- | ------------- |
| normal   | Collapse  | Collapse        | Wrap          |
| pre      | Preserve  | Preserve        | No wrap       |
| nowrap   | Collapse  | Collapse        | No wrap       |
| pre-wrap | Preserve  | Preserve        | Wrap          |
| pre-line | Preserve  | Collapse        | Wrap          |

## robots

```
<META NAME="ROBOTS" CONTENT="INDEX, FOLLOW">

robots.txt
    User-agent: Google
    Disallow:

    User-agent: *
    Disallow: /tmp/
```

## Frameworks

htmx | AJAX, CSS Transitions, WebSockets and Server Sent Events: https://htmx.org/
