extractors

The extractors module provides libraries for defining a schema to easily and safely extract values from environment variables, URL path elements, and HTML form values.

Getting Started

The extractors package can be installed by running

go get github.com/shoenig/extractors@latest

import (
    github.com/shoenig/extractors/env      // extract values from environment variables
    github.com/shoenig/extractors/urlpath  // extract elements from url paths
    github.com/shoenig/extractors/formdata // extract values from html data
)

env example

Use the env package to parse values from environment variables.

import github.com/shoenig/go-conceal // for storing sensitive values

var (
    go111module string
    sshPID      int
    password    *conceal.Text
)

_ = env.ParseOS(env.Schema{
    "GO111MODULE":   env.String(&go111module, false),
    "SSH_AGENT_PID": env.Int(&sshPID, true),
    "PASSWORD":      env.Secret(&password, true),
})

formdata example

Use the formdata package to parse values from url.Values (typically coming from ``*http.Request.Form` objects from inbound requests.

// typically coming from a *http.Request.Form
values := url.Values{
    "user":     []string{"bob"},
    "age":      []string{"45"},
}

var (
    user string
    age  int
)

_ = formdata.Parse(values, formdata.Schema{
    "user": formdata.String(&user),
    "age":  formdata.Int(&age),
})

urlpath example

Use the urlpath package to parse URL path elements when using a gorilla/mux router.

// with a mux handler definition like
router.Handle("/{kind}/{id}")

// in the handler implementation, parse the *http.Request URL with
var (
    kind string
    id   int
)

_ = urlpath.Parse(request, urlpath.Schema{
    "kind": urlpath.String(&kind),
    "id":   urlpath.Int(&id),
})

Contributing

The github.com/shoenig/extractors module is always improving with new features and error corrections. For contributing bug fixes and new features please file an issue.

License

The github.com/shoenig/extractors module is open source under the BSD-3-Clause license.