// Copyright 2019 Google LLC
//
// 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
//
// https://www.apache.org/licenses/LICENSE-2.0
//
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// 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.
// Note: this file is purely for documentation. Any contents are not expected
// to be loaded as the JS file.
/**
* `FieldMask` represents a set of symbolic field paths, for example:
*
* paths: "f.a"
* paths: "f.b.d"
*
* Here `f` represents a field in some root message, `a` and `b`
* fields in the message found in `f`, and `d` a field found in the
* message in `f.b`.
*
* Field masks are used to specify a subset of fields that should be
* returned by a get operation or modified by an update operation.
* Field masks also have a custom JSON encoding (see below).
*
* # Field Masks in Projections
*
* When used in the context of a projection, a response message or
* sub-message is filtered by the API to only contain those fields as
* specified in the mask. For example, if the mask in the previous
* example is applied to a response message as follows:
*
* f {
* a : 22
* b {
* d : 1
* x : 2
* }
* y : 13
* }
* z: 8
*
* The result will not contain specific values for fields x,y and z
* (their value will be set to the default, and omitted in proto text
* output):
*
*
* f {
* a : 22
* b {
* d : 1
* }
* }
*
* A repeated field is not allowed except at the last position of a
* paths string.
*
* If a FieldMask object is not present in a get operation, the
* operation applies to all fields (as if a FieldMask of all fields
* had been specified).
*
* Note that a field mask does not necessarily apply to the
* top-level response message. In case of a REST get operation, the
* field mask applies directly to the response, but in case of a REST
* list operation, the mask instead applies to each individual message
* in the returned resource list. In case of a REST custom method,
* other definitions may be used. Where the mask applies will be
* clearly documented together with its declaration in the API. In
* any case, the effect on the returned resource/resources is required
* behavior for APIs.
*
* # Field Masks in Update Operations
*
* A field mask in update operations specifies which fields of the
* targeted resource are going to be updated. The API is required
* to only change the values of the fields as specified in the mask
* and leave the others untouched. If a resource is passed in to
* describe the updated values, the API ignores the values of all
* fields not covered by the mask.
*
* If a repeated field is specified for an update operation, new values will
* be appended to the existing repeated field in the target resource. Note that
* a repeated field is only allowed in the last position of a `paths` string.
*
* If a sub-message is specified in the last position of the field mask for an
* update operation, then new value will be merged into the existing sub-message
* in the target resource.
*
* For example, given the target message:
*
* f {
* b {
* d: 1
* x: 2
* }
* c: [1]
* }
*
* And an update message:
*
* f {
* b {
* d: 10
* }
* c: [2]
* }
*
* then if the field mask is:
*
* paths: ["f.b", "f.c"]
*
* then the result will be:
*
* f {
* b {
* d: 10
* x: 2
* }
* c: [1, 2]
* }
*
* An implementation may provide options to override this default behavior for
* repeated and message fields.
*
* In order to reset a field's value to the default, the field must
* be in the mask and set to the default value in the provided resource.
* Hence, in order to reset all fields of a resource, provide a default
* instance of the resource and set all fields in the mask, or do
* not provide a mask as described below.
*
* If a field mask is not present on update, the operation applies to
* all fields (as if a field mask of all fields has been specified).
* Note that in the presence of schema evolution, this may mean that
* fields the client does not know and has therefore not filled into
* the request will be reset to their default. If this is unwanted
* behavior, a specific service may require a client to always specify
* a field mask, producing an error if not.
*
* As with get operations, the location of the resource which
* describes the updated values in the request message depends on the
* operation kind. In any case, the effect of the field mask is
* required to be honored by the API.
*
* ## Considerations for HTTP REST
*
* The HTTP kind of an update operation which uses a field mask must
* be set to PATCH instead of PUT in order to satisfy HTTP semantics
* (PUT must only be used for full updates).
*
* # JSON Encoding of Field Masks
*
* In JSON, a field mask is encoded as a single string where paths are
* separated by a comma. Fields name in each path are converted
* to/from lower-camel naming conventions.
*
* As an example, consider the following message declarations:
*
* message Profile {
* User user = 1;
* Photo photo = 2;
* }
* message User {
* string display_name = 1;
* string address = 2;
* }
*
* In proto a field mask for `Profile` may look as such:
*
* mask {
* paths: "user.display_name"
* paths: "photo"
* }
*
* In JSON, the same mask is represented as below:
*
* {
* mask: "user.displayName,photo"
* }
*
* # Field Masks and Oneof Fields
*
* Field masks treat fields in oneofs just as regular fields. Consider the
* following message:
*
* message SampleMessage {
* oneof test_oneof {
* string name = 4;
* SubMessage sub_message = 9;
* }
* }
*
* The field mask can be:
*
* mask {
* paths: "name"
* }
*
* Or:
*
* mask {
* paths: "sub_message"
* }
*
* Note that oneof type names ("test_oneof" in this case) cannot be used in
* paths.
*
* ## Field Mask Verification
*
* The implementation of any API method which has a FieldMask type field in the
* request should verify the included field paths, and return an
* `INVALID_ARGUMENT` error if any path is duplicated or unmappable.
*
* @property {string[]} paths
* The set of field mask paths.
*
* @typedef FieldMask
* @memberof google.protobuf
* @see [google.protobuf.FieldMask definition in proto format]{@link https://github.com/google/protobuf/blob/master/src/google/protobuf/field_mask.proto}
*/
const FieldMask = {
// This is for documentation. Actual contents will be loaded by gRPC.
};