## Migration Guide
### Migrating from V1 to V2
1. Support for `<xmp>` tag is removed; use `<script type="text/markdown">` instead.
```html
<!-- Previous -->
<zero-md>
<template>
<xmp>
# `This` is my [markdown](example.md)
</xmp>
</template>
</zero-md>
<!-- Now -->
<zero-md>
<!-- No need to wrap with <template> tag -->
<script type="text/markdown">
# `This` is my [markdown](example.md)
</script>
</zero-md>
<!-- If you need your code to be pretty, -->
<zero-md>
<!-- Set `data-dedent` to opt-in to dedent the text during render -->
<script type="text/markdown" data-dedent>
# It is important to be pretty
So having spacing makes me happy.
</script>
</zero-md>
```
2. Markdown source behaviour has changed. Think of `<script type="text/markdown">` as a "fallback".
```html
<!-- Previous -->
<zero-md src="will-not-render.md">
<template>
<xmp>
# This has first priority and will be rendered instead of `will-not-render.md`
</xmp>
</template>
<zero-md>
<!-- Now -->
<zero-md src="will-render-unless-falsy.md">
<script type="text/markdown">
# This will NOT be rendered *unless* `src` resolves to falsy
</script>
<zero-md>
```
3. The `css-urls` attribute is deprecated. Use `<link rel="stylesheet">` instead.
```html
<!-- Previous -->
<zero-md src="example.md" css-urls='["/style1.css", "/style2.css"]'><zero-md>
<!-- Now, this... -->
<zero-md src="example.md"></zero-md>
<!-- ...is actually equivalent to this -->
<zero-md src="example.md">
<template>
<!-- These are the default stylesheets -->
<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/sindresorhus/github-markdown-css@4/github-markdown.min.css">
<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/PrismJS/prism@1/themes/prism.min.css">
</template>
</zero-md>
<!-- So, to apply your own external stylesheets... -->
<zero-md src="example.md">
<!-- ...you overwrite the default template -->
<template>
<!-- Use <link> tags to reference your own stylesheets -->
<link rel="stylesheet" href="/style1.css">
<link rel="stylesheet" href="/style2.css">
<!-- You can even apply additional styles -->
<style>
p {
color: red;
}
</style>
</template>
</zero-md>
<!-- If you like the default stylesheets but wish to apply some overrides -->
<zero-md src="example.md">
<!-- Set `data-merge` to "append" to apply this template AFTER the default template -->
<!-- Or "prepend" to apply this template BEFORE -->
<template data-merge="append">
<style>
p {
color: red;
}
</style>
</template>
</zero-md>
```
4. The attributes `marked-url` and `prism-url` are deprecated. To load `marked` or `prism` from another
location, simply load their scripts *before* importing `zero-md`.
```html
<head>
...
<script defer src="/lib/marked.js"></script>
<script defer src="/lib/prism.js"></script>
<script type="module" src="/lib/zero-md.min.js"></script>
</head>
```
5. The global config object has been renamed from `ZeroMd.config` to `ZeroMdConfig`.
```html
<!-- Previous -->
<script src="/node_modules/@webcomponents/webcomponentsjs/webcomponents-loader.js"></script>
<script>
window.ZeroMd = {
config: {
cssUrls: [
'/styles/my-markdown-theme.css',
'/styles/my-highlight-theme.css'
]
}
};
</script>
<script type="module" src="https://cdn.jsdelivr.net/gh/zerodevx/zero-md@1/src/zero-md.min.js"></script>
<!-- Now -->
<script>
window.ZeroMdConfig = {
cssUrls: [
'/styles/my-markdown-theme.css',
'/styles/my-highlight-theme.css'
]
}
</script>
<script type="module" src="https://cdn.jsdelivr.net/gh/zerodevx/zero-md@2/dist/zero-md.min.js"></script>
```
6. The convenience events `zero-md-marked-ready` and `zero-md-prism-ready` are removed and **will no longer fire**.
Instead, the `zero-md-ready` event guarantees that everything is ready, and that render can begin.