# Development post-it notes.
Things/Snippets of code I should not forget.

Made as a quick cheatsheet for me and contributors to check if they're in doubt.

## Using context to retrieve important values.
Certain middlewares will store a couple of values on the context to make your developer life easier. Here's a couple examples:

```go
user, ok := r.Context().Value(lib.UserKey).(*types.User)
session, ok := r.Context().Value(lib.SessionKey).(string)
loggedIn, ok := r.Context().Value(lib.LoggedInKey).(bool) // this should be fine to be used anywhere.
repo, ok := r.Context().Value(md.RepoKey).(types.Repo) // provided by the repo middleware
```

**IMPORTANT** *AND* **TODO**: use `val, ok := ctx.Value(key).(Type); if !ok { ... }` to check if the value is set.

## Form validation.
Use the md.ValidateForm such as
```go
type LoginForm struct {
	Email    string `form:"email"    validate:"required,email"`
	Password string `form:"password" validate:"required,min=8"`
}

md.ValidateForm[LoginForm](http.HandlerFunc(a.login)) // Use handle, not handleFunc.
```

and retrieve the form using 

```go
form, ok := md.Form[LoginForm](r) // r being the request
```

Bear in mind forms have that special property because of `contextKey`.

Forms are CSRF-protected. `{{ .csrfField }}` must be added inside each form.

## Mux routing.
I use `gorilla/mux` as a router:

- Use a blank space `""` for indexes.
- Use `{path:.+}` for those recursive paths.
- Define all routers in app.go since it's be easier to manage.

## Rendering templates.
Use the following code:

```go
a.Render(w, r, "base", "repo/view", map[string]any{"Repo": repo})
```

Where `a` is your *App, `base` the layout, `repo/view` is the template, and `map[string]any{"Repo": repo}` is the data, accessible as `.Repo`

Use `{{.sshDomain}}` and `{{.sshPort}}` to get the domain and port the SSH server will be listening at.

Useful variables:
```go
{{.loggedIn}} //  bool, is user logged in? self-explanatory.
{{.user}} // types.User (if loggedIn is true)
{{.sshDomain}} // domain of the SSH server.
{{.sshPort}} // port which the SSH server is listening from.
```

When you need to access the root "." while (e.g) ranging, use "$" to access it. Example:
```go
{{range .Files}}
    {{$.DirectoryName}}/{{.Name}}
{{end}}
``` 

### Template rendering utils.
I made a couple utils to be used on the templates.

For instance:

```go
{{if IsText .Blob.Type}}
    <pre><code>{{.Blob.Content}}</code></pre>
{{else if IsImage .Blob.Mime}}
    <img src="{{Src .Blob.Content .Blob.Mime}}">
{{end}}
```

ALWAYS USE `{{RepoRoot .Meta}}` instead of "/~(user)/(repo-name)/". It's easier to change later.
It has a leading slash and no trailing slash.

```go
{{RepoRoot .DBRepo}} -> "/~poyo/banana"
{{TruncateStr "hello world" 5}} // -> "hello"
{{Mime .Blob}} // -> "image/png"
```

You can check the full list at the templating function itself.

### Time.
When rendering a date, pass in a UTC date into any element with a class `local-time`, and `time.js` will convert it to the user's local time.

Example:
```html
<time class="local-time" datetime="{{.CreatedAt}}">{{.CreatedAt}}</time>
```

### CSS Styling:
`.inline` for inlined and gapped containers.

## Message and Error displaying.
`?msg=AuthSuccess` and `?err=RequireAuth` are examples of query params that will show a banner on the page.

Keep in mind, validation errors are Base64 encoded (urlencoded) and are passed as `?err=ValidationErr-(base64)`. The messages and validation middleware handle it, so don't worry about it much.
CSS for errors and messages is on the main stylesheet (`styles.css`).

`.message`, `.warning` and `.error` have a slight vertical margin. If you use the same class names as HTML attributes, they will have no margin. 

## Lib/Submodules.
Please, separate stuff into lib submodules to avoid circular imports.

I had to suffer an hour of debugging because I implemented git handling on a db function. I scrapped everything and rewrote it separately, and it worked. That's proof separating is better!

## Hackatime.
Users can login using Hack Club's Hackatime. Why? To get stats on their projects.

## Git.
When opening a repo with `git.Repo()`, make sure to add `defer repo.Close()` after it.

## Resources
 - [https://github.com/firecracker-microvm/firecracker/blob/main/docs/prod-host-setup.md](Firecracker production guide)