| /* |
| Copyright 2017 The Kubernetes Authors. |
| |
| Licensed under the Apache License, Version 2.0 (the "License"); |
| you may not use this file except in compliance with the License. |
| You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| */ |
| |
| package explain |
| |
| import ( |
| "fmt" |
| |
| "k8s.io/kube-openapi/pkg/util/proto" |
| ) |
| |
| // fieldLookup walks through a schema by following a path, and returns |
| // the final schema. |
| type fieldLookup struct { |
| // Path to walk |
| Path []string |
| |
| // Return information: Schema found, or error. |
| Schema proto.Schema |
| Error error |
| } |
| |
| // SaveLeafSchema is used to detect if we are done walking the path, and |
| // saves the schema as a match. |
| func (f *fieldLookup) SaveLeafSchema(schema proto.Schema) bool { |
| if len(f.Path) != 0 { |
| return false |
| } |
| |
| f.Schema = schema |
| |
| return true |
| } |
| |
| // VisitArray is mostly a passthrough. |
| func (f *fieldLookup) VisitArray(a *proto.Array) { |
| if f.SaveLeafSchema(a) { |
| return |
| } |
| |
| // Passthrough arrays. |
| a.SubType.Accept(f) |
| } |
| |
| // VisitMap is mostly a passthrough. |
| func (f *fieldLookup) VisitMap(m *proto.Map) { |
| if f.SaveLeafSchema(m) { |
| return |
| } |
| |
| // Passthrough maps. |
| m.SubType.Accept(f) |
| } |
| |
| // VisitPrimitive stops the operation and returns itself as the found |
| // schema, even if it had more path to walk. |
| func (f *fieldLookup) VisitPrimitive(p *proto.Primitive) { |
| // Even if Path is not empty (we're not expecting a leaf), |
| // return that primitive. |
| f.Schema = p |
| } |
| |
| // VisitKind unstacks fields as it finds them. |
| func (f *fieldLookup) VisitKind(k *proto.Kind) { |
| if f.SaveLeafSchema(k) { |
| return |
| } |
| |
| subSchema, ok := k.Fields[f.Path[0]] |
| if !ok { |
| f.Error = fmt.Errorf("field %q does not exist", f.Path[0]) |
| return |
| } |
| |
| f.Path = f.Path[1:] |
| subSchema.Accept(f) |
| } |
| |
| // VisitReference is mostly a passthrough. |
| func (f *fieldLookup) VisitReference(r proto.Reference) { |
| if f.SaveLeafSchema(r) { |
| return |
| } |
| |
| // Passthrough references. |
| r.SubSchema().Accept(f) |
| } |
| |
| // LookupSchemaForField looks for the schema of a given path in a base schema. |
| func LookupSchemaForField(schema proto.Schema, path []string) (proto.Schema, error) { |
| f := &fieldLookup{Path: path} |
| schema.Accept(f) |
| return f.Schema, f.Error |
| } |