Add datetime attribute (#177)

`<time>`, `<del>` and `<ins>` can receive a
[`datetime`](https://developer.mozilla.org/en-US/docs/Web/API/HTMLTimeElement/dateTime)
attribute

Add an `Iff` helper (#172)

I ran into some situation where I want to conditionally render a node if
some variable is not nil and obviously I got a panic

```go
// package viewmodels
type SomePage struct {
	s *string
}

// package views
func SomePage (vm viewmodels.SomePage) g,Node {
	return Div(
		If(vm.s == nil, Text("s is nil"),
		If(vm.s !- nil, Text("s is " + vm.s), // this will panic when `s` is nil
	)
}
```

In this situation, go will interpret the code of the second `if`
regardless of the condition because the code itself is not in a
condition.

This PR introduces a new `Iff` helper that accepts a callback. The
callback content is only interpreted when it's called, making the code
safe:

```go
// package viewmodels
type SomePage struct {
	s *string
}

// package views
func SomePage (vm viewmodels.SomePage) g,Node {
	return Div(
		Iff(vm.s == nil, func () g.Node { return Text("s is nil") },
		Iff(vm.s !- nil, func () g.Node { return Text("s is " + vm.s) },
	)
}
```

I'm aware of the `Lazy` effort on the side, but I guess this is no a
breaking change and can still exist in addition to the `Lazy` effort.

Co-authored-by: Markus Wüstenberg <markus@maragu.dk>

Add dir (#176)

`dir` is a global attribute that lets you specify whether text is RTL or
LTR or if it should be determined by the browser.

Documentation:
https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/dir

Add LabelAttr and List attributes (#175)

Fixes #168 and fixes #169.

Deprecate DataAttr, StyleAttr, TitleAttr, FormEl (#174)

This change addresses #170 by deprecating some HTML helpers in favor of
using one of the styles as a main one, selected based on what I think is
the main use case.

- For `Data`, it's the attribute. I don't see much use of the `<data>`
element in the wild.
- For `Style`, it's the attribute. The `style` attribute is everywhere,
the `<style>` element is perhaps less so (but not much). This was the
hardest one to decide.
- For `Title`, it's the attribute. The `<title>` element only shows up
once per document.
- For `Form`, it's the element. I haven't seen much use of the `form`
attribute in the wild.

I know this is arguably not a "consistent" approach, but I think it
makes for a much nicer API, simply because the most-used option will not
be a suffixed version.

Add script's `integrity` and `crossorigin` attributes (#173)

When using `<script>` to pull a library from a CDN, it's usually a good
idea to attach an integrity check so that if they get hacked and someone
changes all the script, malicious scripts don't get executed on your
website.

To achieve this, you need to attach `integrity` and `crossorigin` to
your `<script/>` tag

```go
Script(
	Scr("https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta1/dist/js/bootstrap.bundle.min.js"),
	Integrity("sha384-ygbV9kiqUc6oa4msXn9868pTtWMgiQaeYH7/t7LECLbyPA2x65Kgf80OJFdroafW"),
	CrossOrigin("anonymous"),
)
```
Turns into
```html
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta1/dist/js/bootstrap.bundle.min.js" 
    integrity="sha384-ygbV9kiqUc6oa4msXn9868pTtWMgiQaeYH7/t7LECLbyPA2x65Kgf80OJFdroafW" 
    crossorigin="anonymous"></script>
```

Hint for whoever likes unpkg.com, adding `?meta` at the end of any
script you import form them will give you the current `integrity` for
the file. Example: https://unpkg.com/three@0.165.0/build/three.cjs?meta

Revert "Add Marquee element promotion to readme"

This reverts commit b33f84310916b238af0006fb151a4b980721bc33.

Add Marquee element promotion to readme

Just call it HTML components in readme

Fix wrong codecov (#166)

We don't need coverage for the example code and internal testing
helpers.

Test on Go 1.22 in CI (#165)

Move logo in readme

Create FUNDING.yml

Fix logo size in readme

Add logo to readme

Test Go 1.21 in CI (#147)

Add "checked" bool attribute (#136)

Fixes #127.

Document Text/Textf helpers better (#135)

Both in the readme and package doc.

Fixes #133.

Test with Go 1.20 in CI (#134)

Fixes #129.

Add Step attribute (#126)

See https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input#step

Fixes #120.

Add ColSpan and RowSpan attributes (#125)

Remove year from LICENSE (#121)

Upgrade codecov-action to v3 in CI (#119)

Put .PHONY in front of each target in Makefile (#118)

Rename master branch to main (#117)

Add stroke-width SVG attribute (#116)

Delete low-value helper components (#115)

I'd rather reserve the package for components that have proven
repeatedly useful, like `Classes` and `HTML5`.

Add Rawf (#114)

Like `Raw`, but interpolates like `Textf`.

Add Go report card to readme (#111)

Also fix godoc badge to point to pkg.go.dev.

Fix small typo occured -> occurred (#110)

Add EncType html attribute (#109)

Add generic Map implementation (#108)

Instead of waiting for a good time to switch the `Map` implementation,
I've decided to just offer two implementations: one for Go versions
before 1.18, and one for 1.18 and onwards. This is achieved using build
tags in the source files.

This is obviously a breaking change for consumers of this library that
use Go 1.18 and onwards.

See #88

Add Go 1.19 to test matrix (#107)

Use output of strings.Builder in assert.Equal (#106)

Make void elements a map (#103)

Makes it easier to lookup by name.

Also, fixed some doc comments.

Update package doc to reflect new content (#102)

It hadn't been updated in a while.

Fix CI badge in Readme (#100)

Update CI config (#98)

- Drop current test workflows if a new one has come in
- Use newer checkout and setup actions
- Delete CodeQL workflow

Update copyright year in license

Use a test matrix with the last three stable Go versions (#96)

Add http.Adapt function (#92)

In the new package `http`, an `Adapt` function converts a `Handler` into a `http.HandlerFunc` from the `http` stdlib package.

Test using Go 1.17 (#91)

Also set the new `-shuffle` flag when testing.

Mark the assert test helpers as such (#90)

Using `t.Helper()`.

Also move the assert package to be internal.

Add loading and srcset HTML attributes (#86)

Useful for `img` and `picture` elements.

Fixes #85.

Co-authored-by: Josep Jesus Bigorra Algaba <josep@prowarehouse.nl>

Add link to maragu.dk and golang.dk in readme

Add Github action status badge to readme

Add contributors file

Add video element and related attributes (#84)

Adds the `video` element and `loop`, `muted`, `playsinline`, `poster` attributes.

Add javascript alert onclick handler to Raw example (#82)

Makes for fun XSS testing.

Add examples in test files (#80)

These show up in godoc.

Add LinkStylesheet and LinkPreload components (#79)

These are often used in the `<head>` part of the HTML.

Escape Attr values (#77)

Because this can be a place of injection if untrusted data is passed, escape all attribute values.

Fixes #74.

Fix TailwindCSS CDN URL in example (#76)

The CSS style URLs from unpkg.com redirected to a different page, but the first request set a `Content-Type` header of `text/plain`. Using the direct URLs fixes this.

Fixes #75. Thanks to @gedw99 for reporting.

Update readme with content from website (#73)

Bump Go version to 1.16 in CI (#72)

Add more complex example using TailwindCSS (#71)

Add svg package and a few helpers (#67)

Introducing SVG, to inline vector graphics in your HTML! 🥳

Fix code in readme (#69)

Broken in #66.

Update license year (#68)

Streamline HTML element API (#66)

There were a lot of elements previously, like `Em`, `H1`, and a lot more, that took a string as the first argument previously. This was weird when you wanted to mix elements to output html like `<strong><em>…</em></strong>` or `<h1>Something <em>something</em> something</h1>`. gomponents is not an HTML validator, so I want people to be able to use elements however they please, also without text content.

This also means that all elements now have the same API.

Use g.If in HTML5 helper (#65)

Inlining looks much nicer.

Return Node from all helpers instead of NodeFunc (#62)

This makes it clearer that the helpers return a `Node` of any kind, and that the type is not important.

This also streamlines the API, as attribute helpers already return just `Node`.

Add data- attribute helper (#61)

Fixes #49.

Add test for InputHidden (#60)

Add aria-* and role attributes (#59)

Fixes #50.

Add If helper function (#57)

Used to inline conditional nodes.

Change main example to be the dot-import version (#56)

Simplify available elements (#55)

`a`, `form`, `img`, `input`, `label`, `option`, `progress`, `select`, and `textarea` are now just regular elements (without helper parameters), because:
- Sometimes the use case doesn't fit (`a` as anchor without href, for example)
- There's no reason these are special among the others, so streamlining them makes sense

Also added new attributes `action`, `alt`, `for`, `method` that I had somehow missed.

Rename Document to Doctype (#54)

Move elements and attributes into html package (#52)

This makes it easier to use dot-imports.

Also updated the readme and examples with new usage, and move the `Classes` helper into the `components` package.

Minor refactoring and comment changes (#51)

Add example with dot imports (#47)

Add svg element (#46)

Also add `cols` and `rows` attributes.

Fixes #43.

Add NodeType which replaces the Placer interface (#45)

The `Placer` interface was a weird interface that tried to abstract away nodes being elements or attributes, but it doesn't really make sense. Now `Nodes` just have a `NodeType`.

Render correct HTML5 (#44)

Previously, elements of kind void and empty elements generally would be rendered auto-closing (with a final `/` character in the start tag), which is allowed sometimes but arguably wrong. See https://dev.w3.org/html5/spec-LC/syntax.html#end-tags

This created problems with for example `textarea` and `script`, which cannot be auto-closing, or the browser renders it wrong.

Also clarified in the docs that this library outputs HTML5.

Fixes #42.

Add package docs (#41)

Also update readme with features.

Add Map function (#40)

`Map` makes it easier to build lists of elements without having to iterate.

Render to Writer instead of string (#39)

The Render function has been changed to take a `Writer` instead of returning a string. This makes it possible to generate documents without having the whole content in memory.

This also removes the `gomponents.Write` function, which is now redundant.

Furthermore, the `el.Document` function has been changed to only take one child, as multiple children never make sense for it. (It's not even a child, more a sibling.)

Remove fmt.Sprintf call in attribute Render (#38)

Just concatenating the strings is much faster.

Before:

```
make benchmark
go test -bench=.
goos: darwin
goarch: amd64
pkg: github.com/maragudk/gomponents
BenchmarkAttr/boolean_attributes-8         	 8194791	       139 ns/op
BenchmarkAttr/name-value_attributes-8      	 5143292	       229 ns/op
PASS
ok  	github.com/maragudk/gomponents	2.841s
```

After:

```
make benchmark
go test -bench=.
goos: darwin
goarch: amd64
pkg: github.com/maragudk/gomponents
BenchmarkAttr/boolean_attributes-8         	16755404	        67.0 ns/op
BenchmarkAttr/name-value_attributes-8      	10208625	       116 ns/op
PASS
ok  	github.com/maragudk/gomponents	2.702s
```

Pass attributes as pointers (#37)

Add HTML5 document template (#36)

Add attribute helpers (#35)

Also refactor tests to be table-driven, for readability.

Add element helpers and refactor (#34)

This change adds a lot of element helpers, and refactors:
- helpers into simple, text, and other helpers
- most tests into table-driven tests, so they're easier to read

Thanks to @oderwat for pushing me to improve the tests. 😉

Add contributing instructions (#33)

Add br and hr element helpers (#30)

Remove "fmt" import in readme example (#31)

Also style menu in simple example slightly.

Don't render or error on nil children (#32)

This makes it easier to e.g. conditionally skip a component for rendering.

Add Group function to group Nodes (#29)

Update package doc for gomponents (#28)

Use HTMLEscapeString in Textf (#27)

Add remaining sectioning elements as helpers (#25)

Fixes #22.

Use HTMLEscapeString (#24)

HTMLEscaper is not needed with strings.

Update readme with blog post link (#23)

Group element helpers in different files (#21)

According to the section at https://developer.mozilla.org/en-US/docs/Web/HTML/Element

Add space before auto-closing element (#20)

Add convenience helpers for form elements (#19)

Introduce Placer interface (#18)

When implemented, the `Place` method of the `Placer` interface tells `Render` in `El` where to put a Node. This is relevant for helpers that want to be rendered like attributes, inside the parent element.

Fixes the bug where `attr.Classes` was rendered outside the element.

Add Textf function (#17)

Like Text, but calls fmt.Sprintf before rendering.

Add better example in readme (#16)

Add children varargs to h1-6, b, strong, i, em, img helpers (#15)

This makes it possible to add attributes.

Make attr.Classes a map type (#14)

This makes the usage syntax prettier. Instead of `attr.Classes(map[string]bool{})`, we can just use `attr.Classes{}`.

Add simple example (#13)

Add a test for attr.String (#12)

Add a Write function (#11)

Add a lot of common elements (#10)

Especially add elements that are either used in every document, that nearly always have text content, or that are almost always used with certain attributes.

Don't render twice with children (#9)

Add package el with element helpers (#8)

Add package attr with attribute helpers (#7)

Make NodeFunc and attr implement fmt.Stringer (#6)

Try out codecov.io (#5)

Add Makefile (#4)

Create codeql-analysis.yml (#3)

Add godoc link to readme (#2)

Add package documentation (#1)

Add first implementation of Node, El, Attr, Text

Make version numbers strings in yaml

Test with Go 1.20 in CI

Document Text/Textf helpers better

Both in the readme and package doc.

Fixes #133.

Add "checked" bool attribute

Fixes #127.

Test Go 1.21 in CI

Test on Go 1.22 in CI

Fix wrong codecov

We don't need coverage for the example code and internal testing helpers.

add script's integrity and crossorigin attributes

Fix readme

Deprecate DataAttr, StyleAttr, TitleAttr, FormEl

This change addresses #170 by deprecating some HTML helpers in favor of using one of the styles as a main one,
selected based on what I think is the main use case.

- For `Data`, it's the attribute. I don't see much use of the `<data>` element in the wild.
- For `Style`, it's the attribute. The `style` attribute is everywhere, the `<style>` element is perhaps less so (but not much). This was the hardest one to decide.
- For `Title`, it's the attribute. The `<title>` element only shows up once per document.
- For `Form`, it's the element. I haven't seen much use of the `data` attribute in the wild.

I know this is arguably not a "consistent" approach, but I think it makes for a much nicer API, simply because the most-used option will not be a suffixed version.