// Attribute implements the attribute definition DSL. An attribute describes a data structure
// recursively. Attributes are used for describing request headers, parameters and payloads -
// response bodies and headers - media types and types. An attribute definition is recursive:
// attributes may include other attributes. At the basic level an attribute has a name,
// a type and optionally a default value and validation rules. The type of an attribute can be one of:
//
// * The primitive types Boolean, Integer, Number or String.
//
// * A type defined via the Type function.
//
// * A media type defined via the MediaType function.
//
// * An object described recursively with child attributes.
//
// * An array defined using the ArrayOf function.
//
// * An hashmap defined using the HashOf function.
//
// Attributes can be defined using the Attribute, Param, Member or Header functions depending
// on where the definition appears. The syntax for all these DSL is the same.
// Here are some examples:
//
// Attribute("name") // Defines an attribute of type String
//
// Attribute("name", func() {
// Pattern("^foo") // Adds a validation rule to the attribute
// })
//
// Attribute("name", Integer) // Defines an attribute of type Integer
//
// Attribute("name", Integer, func() {
// Default(42) // With a default value
// })
//
// Attribute("name", Integer, "description") // Specifies a description
//
// Attribute("name", Integer, "description", func() {
// Enum(1, 2) // And validation rules
// })
//
// Nested attributes:
//
// Attribute("nested", func() {
// Description("description")
// Attribute("child")
// Attribute("child2", func() {
// // ....
// })
// Required("child")
// })
//
// Here are all the valid usage of the Attribute function:
//
// Attribute(name string, dataType DataType, description string, dsl func())
//
// Attribute(name string, dataType DataType, description string)
//
// Attribute(name string, dataType DataType, dsl func())
//
// Attribute(name string, dataType DataType)
//
// Attribute(name string, dsl func()) // dataType is String or Object (if DSL defines child attributes)
//
// Attribute(name string) // dataType is String
func Attribute(name string, args ...interface{}) {
var parent *design.AttributeDefinition
if at, ok := attributeDefinition(false); ok {
parent = at
} else if mt, ok := mediaTypeDefinition(true); ok {
parent = mt.AttributeDefinition
}
if parent != nil {
if parent.Type == nil {
parent.Type = design.Object{}
}
if _, ok := parent.Type.(design.Object); !ok {
ReportError("can't define child attributes on attribute of type %s", parent.Type.Name())
return
}
var baseAttr *design.AttributeDefinition
if parent.Reference != nil {
if att, ok := parent.Reference.ToObject()[name]; ok {
baseAttr = att.Dup()
}
}
dataType, description, dsl := parseAttributeArgs(baseAttr, args...)
if baseAttr != nil {
if description != "" {
baseAttr.Description = description
}
if dataType != nil {
baseAttr.Type = dataType
}
} else {
baseAttr = &design.AttributeDefinition{
Type: dataType,
Description: description,
}
}
baseAttr.Reference = parent.Reference
if dsl != nil {
executeDSL(dsl, baseAttr)
}
if baseAttr.Type == nil {
// DSL did not contain an "Attribute" declaration
baseAttr.Type = design.String
}
parent.Type.(design.Object)[name] = baseAttr
}
}
package dsl
import (
"regexp"
"strconv"
"strings"
"github.com/raphael/goa/design"
)
// Attribute implements the attribute definition DSL. An attribute describes a data structure
// recursively. Attributes are used for describing request headers, parameters and payloads -
// response bodies and headers - media types and types. An attribute definition is recursive:
// attributes may include other attributes. At the basic level an attribute has a name,
// a type and optionally a default value and validation rules. The type of an attribute can be one of:
//
// * The primitive types Boolean, Integer, Number or String.
//
// * A type defined via the Type function.
//
// * A media type defined via the MediaType function.
//
// * An object described recursively with child attributes.
//
// * An array defined using the ArrayOf function.
//
// * An hashmap defined using the HashOf function.
//
// Attributes can be defined using the Attribute, Param, Member or Header functions depending
// on where the definition appears. The syntax for all these DSL is the same.
// Here are some examples:
//
// Attribute("name") // Defines an attribute of type String
//
// Attribute("name", func() {
// Pattern("^foo") // Adds a validation rule to the attribute
// })
//
// Attribute("name", Integer) // Defines an attribute of type Integer
//
// Attribute("name", Integer, func() {
// Default(42) // With a default value
// })
//
// Attribute("name", Integer, "description") // Specifies a description
//
// Attribute("name", Integer, "description", func() {
// Enum(1, 2) // And validation rules
// })
//
// Nested attributes:
//
// Attribute("nested", func() {
// Description("description")
// Attribute("child")
// Attribute("child2", func() {
// // ....
// })
// Required("child")
// })
//
// Here are all the valid usage of the Attribute function:
//
// Attribute(name string, dataType DataType, description string, dsl func())
//
// Attribute(name string, dataType DataType, description string)
//
// Attribute(name string, dataType DataType, dsl func())
//
// Attribute(name string, dataType DataType)
//
// Attribute(name string, dsl func()) /* dataType is String or Object (if DSL defines child attributes) */
//
// Attribute(name string) /* dataType is String */
func Attribute(name string, args ...interface{}) {
var parent *design.AttributeDefinition
if at, ok := attributeDefinition(false); ok {
parent = at
} else if mt, ok := mediaTypeDefinition(true); ok {
parent = mt.AttributeDefinition
}
if parent != nil {
if parent.Type == nil {
parent.Type = design.Object{}
} else if _, ok := parent.Type.(design.Object); !ok {
ReportError("can't define child attributes on attribute of type %s", parent.Type.Name())
return
}
var baseAttr *design.AttributeDefinition
if parent.Reference != nil {
for n, att := range parent.Reference.ToObject() {
if n == name {
baseAttr = att.Dup()
break
}
}
}
var dataType design.DataType
var description string
var dsl func()
var ok bool
if len(args) == 0 {
if baseAttr != nil {
dataType = baseAttr.Type
} else {
dataType = design.String
}
} else if len(args) == 1 {
if dsl, ok = args[0].(func()); !ok {
if dataType, ok = args[0].(design.DataType); !ok {
invalidArgError("DataType or func()", args[0])
}
} else if baseAttr != nil {
dataType = baseAttr.Type
}
} else if len(args) == 2 {
if dataType, ok = args[0].(design.DataType); !ok {
invalidArgError("DataType", args[0])
}
if dsl, ok = args[1].(func()); !ok {
if description, ok = args[1].(string); !ok {
invalidArgError("string or func()", args[1])
}
}
} else if len(args) == 3 {
if dataType, ok = args[0].(design.DataType); !ok {
invalidArgError("DataType", args[0])
}
if description, ok = args[1].(string); !ok {
invalidArgError("string", args[1])
}
if dsl, ok = args[2].(func()); !ok {
invalidArgError("func()", args[2])
}
} else {
ReportError("too many arguments in call to Attribute")
}
var att *design.AttributeDefinition
if baseAttr != nil {
att = baseAttr
if description != "" {
att.Description = description
}
if dataType != nil {
att.Type = dataType
}
} else {
att = &design.AttributeDefinition{
Type: dataType,
Description: description,
}
}
att.Reference = parent.Reference
if dsl != nil {
executeDSL(dsl, att)
}
if att.Type == nil {
// DSL did not contain an "Attribute" declaration
att.Type = design.String
}
parent.Type.(design.Object)[name] = att
}
}
