コード例 #1
0
ファイル: media_type.go プロジェクト: konstantin-dzreev/goa
// MediaType implements the media type definition DSL. A media type definition describes the
// representation of a resource used in a response body.
//
// Media types are defined with a unique identifier as defined by RFC6838. The identifier also
// defines the default value for the Content-Type header of responses. The ContentType DSL allows
// overridding the default as shown in the example below.
//
// The media type definition includes a listing of all the potential attributes that can appear in
// the body. Views specify which of the attributes are actually rendered so that the same media type
// definition may represent multiple rendering of a given resource representation.
//
// All media types must define a view named "default". This view is used to render the media type in
// response bodies when no other view is specified.
//
// A media type definition may also define links to other media types. This is done by first
// defining an attribute for the linked-to media type and then referring to that attribute in the
// Links DSL. Views may then elect to render one or the other or both. Links are rendered using the
// special "link" view. Media types that are linked to must define that view. Here is an example
// showing all the possible media type sub-definitions:
//
//    MediaType("application/vnd.goa.example.bottle", func() {
//        Description("A bottle of wine")
//        TypeName("BottleMedia")         // Override default generated name
//        ContentType("application/json") // Override default Content-Type header value
//        Attributes(func() {
//            Attribute("id", Integer, "ID of bottle")
//            Attribute("href", String, "API href of bottle")
//            Attribute("account", Account, "Owner account")
//            Attribute("origin", Origin, "Details on wine origin")
//            Links(func() {
//                Link("account")         // Defines link to Account media type
//                Link("origin", "tiny")  // Set view used to render link if not "link"
//            })
//            Required("id", "href")
//        })
//        View("default", func() {
//            Attribute("id")
//            Attribute("href")
//            Attribute("links")          // Renders links
//        })
//        View("extended", func() {
//            Attribute("id")
//            Attribute("href")
//            Attribute("account")        // Renders account inline
//            Attribute("origin")         // Renders origin inline
//            Attribute("links")          // Renders links
//        })
//     })
//
// This function returns the media type definition so it can be referred to throughout the apidsl.
func MediaType(identifier string, apidsl func()) *design.MediaTypeDefinition {
	if design.Design.MediaTypes == nil {
		design.Design.MediaTypes = make(map[string]*design.MediaTypeDefinition)
	}

	if !dslengine.IsTopLevelDefinition() {
		dslengine.IncompatibleDSL()
		return nil
	}

	// Validate Media Type
	identifier, params, err := mime.ParseMediaType(identifier)
	if err != nil {
		dslengine.ReportError("invalid media type identifier %#v: %s",
			identifier, err)
		// We don't return so that other errors may be
		// captured in this one run.
		identifier = "text/plain"
	}
	canonicalID := design.CanonicalIdentifier(identifier)
	// Validate that media type identifier doesn't clash
	if _, ok := design.Design.MediaTypes[canonicalID]; ok {
		dslengine.ReportError("media type %#v with canonical identifier %#v is defined twice", identifier, canonicalID)
		return nil
	}
	identifier = mime.FormatMediaType(identifier, params)
	lastPart := identifier
	lastPartIndex := strings.LastIndex(identifier, "/")
	if lastPartIndex > -1 {
		lastPart = identifier[lastPartIndex+1:]
	}
	plusIndex := strings.Index(lastPart, "+")
	if plusIndex > 0 {
		lastPart = lastPart[:plusIndex]
	}
	lastPart = strings.TrimPrefix(lastPart, "vnd.")
	elems := strings.Split(lastPart, ".")
	for i, e := range elems {
		elems[i] = strings.Title(e)
	}
	typeName := strings.Join(elems, "")
	if typeName == "" {
		mediaTypeCount++
		typeName = fmt.Sprintf("MediaType%d", mediaTypeCount)
	}
	// Now save the type in the API media types map
	mt := design.NewMediaTypeDefinition(typeName, identifier, apidsl)
	design.Design.MediaTypes[canonicalID] = mt
	return mt
}
コード例 #2
0
ファイル: media_type.go プロジェクト: ajoulie/goa
// MediaType implements the media type definition apidsl. A media type definition describes the
// representation of a resource used in a response body. This includes listing all the *potential*
// resource attributes that can appear in the body. Views specify which of the attributes are
// actually rendered so that the same media type definition may represent multiple rendering of a
// given resource representation.
//
// All media types must define a view named "default". This view is used to render the media type in
// response bodies when no other view is specified.
//
// A media type definition may also define links to other media types. This is done by first
// defining an attribute for the linked-to media type and then referring to that attribute in the
// Links apidsl. Views may then elect to render one or the other or both. Links are rendered using the
// special "link" view. Media types that are linked to must define that view. Here is an example
// showing all the possible media type sub-definitions:
//
//	MediaType("application/vnd.goa.example.bottle", func() {
//		Description("A bottle of wine")
//		TypeName("BottleMedia") 		// Optionally override the default generated name
//		Attributes(func() {
//			Attribute("id", Integer, "ID of bottle")
//			Attribute("href", String, "API href of bottle")
//			Attribute("account", Account, "Owner account")
//			Attribute("origin", Origin, "Details on wine origin")
//			Links(func() {
//				Link("account")		// Defines a link to the Account media type
//				Link("origin", "tiny")	// Overrides the default view used to render links
//			})
//			Required("id", "href")
//		})
//		View("default", func() {
//			Attribute("id")
//			Attribute("href")
//			Attribute("links")	// Default view renders links
//		})
//		View("extended", func() {
//			Attribute("id")
//			Attribute("href")
//			Attribute("account")	// Extended view renders account inline
//			Attribute("origin")	// Extended view renders origin inline
//			Attribute("links")	// Extended view also renders links
//		})
// 	})
//
// This function returns the media type definition so it can be referred to throughout the apidsl.
func MediaType(identifier string, apidsl func()) *design.MediaTypeDefinition {
	if design.Design.MediaTypes == nil {
		design.Design.MediaTypes = make(map[string]*design.MediaTypeDefinition)
	}

	if !dslengine.IsTopLevelDefinition() {
		dslengine.IncompatibleDSL()
		return nil
	}

	// Validate Media Type
	identifier, params, err := mime.ParseMediaType(identifier)
	if err != nil {
		dslengine.ReportError("invalid media type identifier %#v: %s",
			identifier, err)
		// We don't return so that other errors may be
		// captured in this one run.
		identifier = "text/plain"
	}
	canonicalID := design.CanonicalIdentifier(identifier)
	// Validate that media type identifier doesn't clash
	if _, ok := design.Design.MediaTypes[canonicalID]; ok {
		dslengine.ReportError("media type %#v is defined twice", identifier)
		return nil
	}
	parts := strings.Split(identifier, "+")
	// Make sure it has the `+json` suffix (TBD update when goa supports other encodings)
	if len(parts) > 1 {
		parts = parts[1:]
		found := false
		for _, part := range parts {
			if part == "json" {
				found = true
				break
			}
		}
		if !found {
			identifier += "+json"
		}
	}
	identifier = mime.FormatMediaType(identifier, params)
	// Concoct a Go type name from the identifier, should it be possible to set it in the apidsl?
	// pros: control the type name generated, cons: not needed in apidsl, adds one more thing to worry about
	lastPart := identifier
	lastPartIndex := strings.LastIndex(identifier, "/")
	if lastPartIndex > -1 {
		lastPart = identifier[lastPartIndex+1:]
	}
	plusIndex := strings.Index(lastPart, "+")
	if plusIndex > 0 {
		lastPart = lastPart[:plusIndex]
	}
	lastPart = strings.TrimPrefix(lastPart, "vnd.")
	elems := strings.Split(lastPart, ".")
	for i, e := range elems {
		elems[i] = strings.Title(e)
	}
	typeName := strings.Join(elems, "")
	if typeName == "" {
		mediaTypeCount++
		typeName = fmt.Sprintf("MediaType%d", mediaTypeCount)
	}
	// Now save the type in the API media types map
	mt := design.NewMediaTypeDefinition(typeName, identifier, apidsl)
	design.Design.MediaTypes[canonicalID] = mt
	return mt

}
コード例 #3
0
ファイル: media_type.go プロジェクト: ajoulie/goa
// CollectionOf creates a collection media type from its element media type. A collection media
// type represents the content of responses that return a collection of resources such as "list"
// actions. This function can be called from any place where a media type can be used.
// The resulting media type identifier is built from the element media type by appending the media
// type parameter "type" with value "collection".
func CollectionOf(v interface{}, apidsl ...func()) *design.MediaTypeDefinition {
	var m *design.MediaTypeDefinition
	var ok bool
	m, ok = v.(*design.MediaTypeDefinition)
	if !ok {
		if id, ok := v.(string); ok {
			m = design.Design.MediaTypes[design.CanonicalIdentifier(id)]
		}
	}
	if m == nil {
		dslengine.ReportError("invalid CollectionOf argument: not a media type and not a known media type identifier")
		// don't return nil to avoid panics, the error will get reported at the end
		return design.NewMediaTypeDefinition("InvalidCollection", "text/plain", nil)
	}
	id := m.Identifier
	mediatype, params, err := mime.ParseMediaType(id)
	if err != nil {
		dslengine.ReportError("invalid media type identifier %#v: %s", id, err)
		// don't return nil to avoid panics, the error will get reported at the end
		return design.NewMediaTypeDefinition("InvalidCollection", "text/plain", nil)
	}
	hasType := false
	for param := range params {
		if param == "type" {
			hasType = true
			break
		}
	}
	if !hasType {
		params["type"] = "collection"
	}
	id = mime.FormatMediaType(mediatype, params)
	canonical := design.CanonicalIdentifier(id)
	if mt, ok := design.GeneratedMediaTypes[canonical]; ok {
		// Already have a type for this collection, reuse it.
		return mt
	}
	mt := design.NewMediaTypeDefinition("", id, func() {
		if mt, ok := mediaTypeDefinition(); ok {
			// Cannot compute collection type name before element media type DSL has executed
			// since the DSL may modify element type name via the TypeName function.
			mt.TypeName = m.TypeName + "Collection"
			mt.AttributeDefinition = &design.AttributeDefinition{Type: ArrayOf(m)}
			if len(apidsl) > 0 {
				dslengine.Execute(apidsl[0], mt)
			}
			if mt.Views == nil {
				// If the apidsl didn't create any views (or there is no apidsl at all)
				// then inherit the views from the collection element.
				mt.Views = make(map[string]*design.ViewDefinition)
				for n, v := range m.Views {
					mt.Views[n] = v
				}
			}
		}
	})
	// Do not execute the apidsl right away, will be done last to make sure the element apidsl has run
	// first.
	design.GeneratedMediaTypes[canonical] = mt
	return mt
}
コード例 #4
0
ファイル: media_type.go プロジェクト: stuartweir/goa
// CollectionOf creates a collection media type from its element media type. A collection media
// type represents the content of responses that return a collection of resources such as "list"
// actions. This function can be called from any place where a media type can be used.
// The resulting media type identifier is built from the element media type by appending the media
// type parameter "type" with value "collection".
func CollectionOf(v interface{}, apidsl ...func()) *design.MediaTypeDefinition {
	if design.GeneratedMediaTypes == nil {
		design.GeneratedMediaTypes = make(design.MediaTypeRoot)
		dslengine.Roots = append(dslengine.Roots, design.GeneratedMediaTypes)
	}
	var m *design.MediaTypeDefinition
	var ok bool
	m, ok = v.(*design.MediaTypeDefinition)
	if !ok {
		if id, ok := v.(string); ok {
			m = design.Design.MediaTypes[design.CanonicalIdentifier(id)]
		}
	}
	if m == nil {
		dslengine.ReportError("invalid CollectionOf argument: not a media type and not a known media type identifier")
		return nil
	}
	id := m.Identifier
	mediatype, params, err := mime.ParseMediaType(id)
	if err != nil {
		dslengine.ReportError("invalid media type identifier %#v: %s", id, err)
		return nil
	}
	hasType := false
	for param := range params {
		if param == "type" {
			hasType = true
			break
		}
	}
	if !hasType {
		params["type"] = "collection"
	}
	id = mime.FormatMediaType(mediatype, params)
	typeName := m.TypeName + "Collection"
	if mt, ok := design.GeneratedMediaTypes[typeName]; ok {
		// Already have a type for this collection, reuse it.
		return mt
	}
	mt := design.NewMediaTypeDefinition(typeName, id, func() {
		if mt, ok := mediaTypeDefinition(true); ok {
			mt.TypeName = typeName
			mt.AttributeDefinition = &design.AttributeDefinition{Type: ArrayOf(m)}
			mt.APIVersions = m.APIVersions
			if len(apidsl) > 0 {
				dslengine.Execute(apidsl[0], mt)
			}
			if mt.Views == nil {
				// If the apidsl didn't create any views (or there is no apidsl at all)
				// then inherit the views from the collection element.
				mt.Views = make(map[string]*design.ViewDefinition)
				for n, v := range m.Views {
					mt.Views[n] = v
				}
			}
		}
	})
	// Do not execute the apidsl right away, will be done last to make sure the element apidsl has run
	// first.
	design.GeneratedMediaTypes[typeName] = mt
	return mt
}