Function linkForType

hack/docgen/api/main.go:432–479

linkForType returns an anchor to the type if it can be generated. returns empty string if it is not a local type or unrecognized external type.

(t *types.Type, c generatorConfig, typePkgMap map[*types.Type]*apiPackage)

// linkForType returns an anchor to the type if it can be generated. returns
// empty string if it is not a local type or unrecognized external type.
func linkForType(t *types.Type, c generatorConfig, typePkgMap map[*types.Type]*apiPackage) (string, error) {
	t = tryDereference(t) // dereference kind=Pointer

	if isLocalType(t, typePkgMap) {
		return "#" + anchorIDForLocalType(t, typePkgMap), nil
	}

	var arrIndex = func(a []string, i int) string {
		return a[(len(a)+i)%len(a)]
	}

	// types like k8s.io/apimachinery/pkg/apis/meta/v1.ObjectMeta,
	// k8s.io/api/core/v1.Container, k8s.io/api/autoscaling/v1.CrossVersionObjectReference,
	// github.com/knative/build/pkg/apis/build/v1alpha1.BuildSpec
	if t.Kind == types.Struct || t.Kind == types.Pointer || t.Kind == types.Interface || t.Kind == types.Alias {
		id := typeIdentifier(t)                        // gives {{ImportPath.Identifier}} for type
		segments := strings.Split(t.Name.Package, "/") // to parse [meta, v1] from "k8s.io/apimachinery/pkg/apis/meta/v1"

		for _, v := range c.ExternalPackages {
			r, err := regexp.Compile(v.TypeMatchPrefix)
			if err != nil {
				return "", errors.Wrapf(err, "pattern %q failed to compile", v.TypeMatchPrefix)
			}
			if r.MatchString(id) {
				tpl, err := texttemplate.New("").Funcs(map[string]interface{}{
					"lower":    strings.ToLower,
					"arrIndex": arrIndex,
				}).Parse(v.DocsURLTemplate)
				if err != nil {
					return "", errors.Wrap(err, "docs URL template failed to parse")
				}

				var b bytes.Buffer
				if err := tpl.
					Execute(&b, map[string]interface{}{
						"TypeIdentifier":  t.Name.Name,
						"PackagePath":     t.Name.Package,
						"PackageSegments": segments,
					}); err != nil {
					return "", errors.Wrap(err, "docs url template execution error")
				}
				return b.String(), nil
			}
		}
		klog.Warningf("not found external link source for type %v", t.Name)
	}
	return "", nil
}

// tryDereference returns the underlying type when t is a pointer, map, or slice.
func tryDereference(t *types.Type) *types.Type {