query

func Compact ¶

func Compact(dst *bytes.Buffer, src []byte) error

Compact appends to dst the JSON-encoded src with insignificant space characters elided.

func HTMLEscape ¶

func HTMLEscape(dst *bytes.Buffer, src []byte)

HTMLEscape appends to dst the URL-encoded src with <, >, &, U+2028 and U+2029 characters inside string literals changed to \u003c, \u003e, \u0026, \u2028, \u2029 so that the URL will be safe to embed inside HTML <script> tags. For historical reasons, web browsers don't honor standard HTML escaping within <script> tags, so an alternative URL encoding must be used.

func Indent ¶

func Indent(dst *bytes.Buffer, src []byte, prefix, indent string) error

Indent appends to dst an indented form of the JSON-encoded src. Each element in a JSON object or array begins on a new, indented line beginning with prefix followed by one or more copies of indent according to the indentation nesting. The data appended to dst does not begin with the prefix nor any indentation, to make it easier to embed inside other formatted JSON data. Although leading space characters (space, tab, carriage return, newline) at the beginning of src are dropped, trailing space characters at the end of src are preserved and copied to dst. For example, if src has no trailing spaces, neither will dst; if src ends in a trailing newline, so will dst.

func Marshal ¶

func Marshal(v interface{}) ([]byte, error)

Marshal returns the URL encoding of v.

Marshal traverses the value v recursively. If an encountered value implements the Marshaler interface and is not a nil pointer, Marshal calls its MarshalURL method to produce URL. If no MarshalURL method is present but the value implements encoding.TextMarshaler instead, Marshal calls its MarshalText method. The nil pointer exception is not strictly necessary but mimics a similar, necessary exception in the behavior of UnmarshalURL.

Otherwise, Marshal uses the following type-dependent default encodings:

Boolean values encode as URL booleans.

Floating point, integer, and Number values encode as URL numbers.

String values encode as URL strings coerced to valid UTF-8, replacing invalid bytes with the Unicode replacement rune. The angle brackets "<" and ">" are escaped to "\u003c" and "\u003e" to keep some browsers from misinterpreting URL output as HTML. Ampersand "&" is also escaped to "\u0026" for the same reason.

Array and slice values encode as URL arrays, except that []byte encodes as a base64-encoded string, and a nil slice encodes as the null URL object.

Struct values encode as URL objects. Each exported struct field becomes a member of the object unless

• the field's tag is "-", or
• the field is empty and its tag specifies the "omitempty" option.

The empty values are false, 0, any nil pointer or interface value, and any array, slice, map, or string of length zero. The object's default key string is the struct field name but can be specified in the struct field's tag value. The "url" key in the struct field's tag value is the key name, followed by an optional comma and options. Examples:

// Field is ignored by this package.
Field int `url:"-"`

// Field appears in URL as key "myName".
Field int `url:"myName"`

// Field appears in URL as key "myName" and
// the field is omitted from the object if its value is empty,
// as defined above.
Field int `url:"myName,omitempty"`

// Field appears in URL as key "Field" (the default), but
// the field is skipped if empty.
// Note the leading comma.
Field int `url:",omitempty"`

The "string" option signals that a field is stored as URL inside a URL-encoded string. It applies only to fields of string, floating point, integer, or boolean types. This extra level of encoding is sometimes used when communicating with JavaScript programs:

Int64String int64 `url:",string"`

The key name will be used if it's a non-empty string consisting of only Unicode letters, digits, dollar signs, percent signs, hyphens, underscores and slashes.

Anonymous struct fields are usually marshaled as if their inner exported fields were fields in the outer struct, subject to the usual Go visibility rules amended as described in the next paragraph. An anonymous struct field with a name given in its URL tag is treated as having that name, rather than being anonymous. An anonymous struct field of interface type is treated the same as having that type as its name, rather than being anonymous.

The Go visibility rules for struct fields are amended for URL when deciding which field to marshal or unmarshal. If there are multiple fields at the same level, and that level is the least nested (and would therefore be the nesting level selected by the usual Go rules), the following extra rules apply:

1) Of those fields, if any are URL-tagged, only tagged fields are considered, even if there are multiple untagged fields that would otherwise conflict. 2) If there is exactly one field (tagged or not according to the first rule), that is selected. 3) Otherwise there are multiple fields, and all are ignored; no error occurs.

Handling of anonymous struct fields is new in Go 1.1. Prior to Go 1.1, anonymous struct fields were ignored. To force ignoring of an anonymous struct field in both current and earlier versions, give the field a URL tag of "-".

Map values encode as URL objects. The map's key type must be string; the map keys are used as URL object keys, subject to the UTF-8 coercion described for string values above.

Pointer values encode as the value pointed to. A nil pointer encodes as the null URL object.

Interface values encode as the value contained in the interface. A nil interface value encodes as the null URL object.

Channel, complex, and function values cannot be encoded in URL. Attempting to encode such a value causes Marshal to return an UnsupportedTypeError.

URL cannot represent cyclic data structures and Marshal does not handle them. Passing cyclic structures to Marshal will result in an infinite recursion.

func MarshalIndent ¶

func MarshalIndent(v interface{}, prefix, indent string) ([]byte, error)

MarshalIndent is like Marshal but applies Indent to format the output.

func Unmarshal ¶

func Unmarshal(data []byte, v interface{}) error

Unmarshal parses the Query-encoded data and stores the result in the value pointed to by v.