github.com/jacobsoderblom/buffalo@v0.11.0/binding/binding.go (about)

     1  package binding
     2  
     3  import (
     4  	"encoding/json"
     5  	"encoding/xml"
     6  	"net/http"
     7  	"strings"
     8  	"sync"
     9  	"time"
    10  
    11  	"github.com/gobuffalo/pop/nulls"
    12  	"github.com/gobuffalo/x/httpx"
    13  	"github.com/monoculum/formam"
    14  	"github.com/pkg/errors"
    15  )
    16  
    17  // Binder takes a request and binds it to an interface.
    18  // If there is a problem it should return an error.
    19  type Binder func(*http.Request, interface{}) error
    20  
    21  // CustomTypeDecoder converts a custom type from the request insto its exact type.
    22  type CustomTypeDecoder func([]string) (interface{}, error)
    23  
    24  // binders is a map of the defined content-type related binders.
    25  var binders = map[string]Binder{}
    26  
    27  var decoder *formam.Decoder
    28  var lock = &sync.Mutex{}
    29  var timeFormats = []string{
    30  	"2006-01-02T15:04:05Z07:00",
    31  	"01/02/2006",
    32  	"2006-01-02",
    33  	"2006-01-02T03:04",
    34  	time.ANSIC,
    35  	time.UnixDate,
    36  	time.RubyDate,
    37  	time.RFC822,
    38  	time.RFC822Z,
    39  	time.RFC850,
    40  	time.RFC1123,
    41  	time.RFC1123Z,
    42  	time.RFC3339,
    43  	time.RFC3339Nano,
    44  	time.Kitchen,
    45  	time.Stamp,
    46  	time.StampMilli,
    47  	time.StampMicro,
    48  	time.StampNano,
    49  }
    50  
    51  // RegisterTimeFormats allows to add custom time layouts that
    52  // the binder will be able to use for decoding.
    53  func RegisterTimeFormats(layouts ...string) {
    54  	timeFormats = append(timeFormats, layouts...)
    55  }
    56  
    57  // RegisterCustomDecorder allows to define custom type decoders.
    58  func RegisterCustomDecorder(fn CustomTypeDecoder, types []interface{}, fields []interface{}) {
    59  	rawFunc := (func([]string) (interface{}, error))(fn)
    60  	decoder.RegisterCustomType(rawFunc, types, fields)
    61  }
    62  
    63  // Register maps a request Content-Type (application/json)
    64  // to a Binder.
    65  func Register(contentType string, fn Binder) {
    66  	lock.Lock()
    67  	defer lock.Unlock()
    68  
    69  	binders[strings.ToLower(contentType)] = fn
    70  }
    71  
    72  // Exec will bind the interface to the request.Body. The type of binding
    73  // is dependent on the "Content-Type" for the request. If the type
    74  // is "application/json" it will use "json.NewDecoder". If the type
    75  // is "application/xml" it will use "xml.NewDecoder". The default
    76  // binder is "https://github.com/monoculum/formam".
    77  func Exec(req *http.Request, value interface{}) error {
    78  	ct := httpx.ContentType(req)
    79  	if ct == "" {
    80  		return errors.New("blank content type")
    81  	}
    82  	if b, ok := binders[ct]; ok {
    83  		return b(req, value)
    84  	}
    85  	return errors.Errorf("could not find a binder for %s", ct)
    86  }
    87  
    88  func init() {
    89  	decoder = formam.NewDecoder(&formam.DecoderOptions{
    90  		TagName:           "form",
    91  		IgnoreUnknownKeys: true,
    92  	})
    93  
    94  	decoder.RegisterCustomType(func(vals []string) (interface{}, error) {
    95  		return parseTime(vals)
    96  	}, []interface{}{time.Time{}}, nil)
    97  
    98  	decoder.RegisterCustomType(func(vals []string) (interface{}, error) {
    99  		var ti nulls.Time
   100  
   101  		t, err := parseTime(vals)
   102  		if err != nil {
   103  			return ti, errors.WithStack(err)
   104  		}
   105  		ti.Time = t
   106  		ti.Valid = true
   107  
   108  		return ti, nil
   109  	}, []interface{}{nulls.Time{}}, nil)
   110  
   111  	sb := func(req *http.Request, i interface{}) error {
   112  		err := req.ParseForm()
   113  		if err != nil {
   114  			return errors.WithStack(err)
   115  		}
   116  
   117  		if err := decoder.Decode(req.Form, i); err != nil {
   118  			return errors.WithStack(err)
   119  		}
   120  		return nil
   121  	}
   122  
   123  	binders["application/html"] = sb
   124  	binders["text/html"] = sb
   125  	binders["application/x-www-form-urlencoded"] = sb
   126  	binders["html"] = sb
   127  }
   128  
   129  func init() {
   130  	jb := func(req *http.Request, value interface{}) error {
   131  		return json.NewDecoder(req.Body).Decode(value)
   132  	}
   133  
   134  	binders["application/json"] = jb
   135  	binders["text/json"] = jb
   136  	binders["json"] = jb
   137  }
   138  
   139  func init() {
   140  	xb := func(req *http.Request, value interface{}) error {
   141  		return xml.NewDecoder(req.Body).Decode(value)
   142  	}
   143  
   144  	binders["application/xml"] = xb
   145  	binders["text/xml"] = xb
   146  	binders["xml"] = xb
   147  }
   148  
   149  func parseTime(vals []string) (time.Time, error) {
   150  	var t time.Time
   151  	var err error
   152  
   153  	// don't try to parse empty time values, it will raise an error
   154  	if len(vals) == 0 || vals[0] == "" {
   155  		return t, nil
   156  	}
   157  
   158  	for _, layout := range timeFormats {
   159  		t, err = time.Parse(layout, vals[0])
   160  		if err == nil {
   161  			return t, nil
   162  		}
   163  	}
   164  
   165  	if err != nil {
   166  		return t, errors.WithStack(err)
   167  	}
   168  
   169  	return t, nil
   170  }