Requests and input

Generic input#

c.Input() merges the request body (JSON object, urlencoded or multipart form) over the query string into a map[string]any, ready for schema parsing:

in, err := c.Input()
if err != nil {
	return err // 400 malformed JSON, 413 too large…
}

• JSON keeps its types; numbers are json.Number.
• Form values are strings; repeated keys and tags[] become lists.
• Bracketed keys nest: author[email]=a@b.c becomes {"author": {"email": "a@b.c"}}, and items[0][name]=x becomes a list of objects.
• Nesting deeper than 16 levels is ignored.

c.QueryInput() does the same for the query string only, and web.FormToMap(values) converts any url.Values.

JSON bodies#

var in struct {
	Title string `json:"title"`
	Body  string `json:"body"`
}
if err := c.BindJSON(&in); err != nil {
	return err
}

BindJSON requires a JSON content type (415 otherwise), and rejects trailing data and bodies over the size limit. Malformed JSON returns a 400 that names the byte offset.

Forms and uploads#

title := c.FormValue("title") // form or query value

file, header, err := c.FormFile("avatar")
if err != nil {
	return err // missing file → 422 with a field error
}
defer file.Close()

Multipart bodies keep up to 8 MiB in memory before spilling to disk.

Body size limits#

Every body read applies web.DefaultMaxBody (10 MiB) unless middleware set a smaller limit. Oversized bodies fail with 413.

r.Post("/upload", upload).Use(middleware.BodyLimit(50 << 20)) // per route
r.Group("/api", func(g *router.Group) {
	g.Use(middleware.BodyLimit(1 << 20))                      // per group
})

Typed binding#

web.Bind[T](c), web.Parse(c, schema), web.ParseQuery and web.ParseParams decode and validate input into Go types in one step. Invalid input becomes an *errs.ValidationError: JSON clients get 422 problem+json, form posts are redirected back with errors and old input flashed. See Validation.

in, err := web.Bind[requests.StorePost](c) // typed requests.StorePost or 422