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core: Add godoc examples for LoadModule

master2
Matthew Holt 2 years ago
parent
commit
fab5e4372a
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2 changed files with 121 additions and 1 deletions
  1. +3
    -1
      context.go
  2. +118
    -0
      context_test.go

+ 3
- 1
context.go View File

@ -124,7 +124,9 @@ func (ctx *Context) OnCancel(f func()) {
// and store them on the same struct. Storing them on the same struct makes for
// easy garbage collection when your host module is no longer needed.
//
// Loaded modules have already been provisioned and validated.
// Loaded modules have already been provisioned and validated. Upon returning
// successfully, this method clears the json.RawMessage(s) in the field since
// the raw JSON is no longer needed, and this allows the GC to free up memory.
func (ctx Context) LoadModule(structPointer interface{}, fieldName string) (interface{}, error) {
val := reflect.ValueOf(structPointer).Elem().FieldByName(fieldName)
typ := val.Type()


+ 118
- 0
context_test.go View File

@ -0,0 +1,118 @@
// Copyright 2015 Matthew Holt and The Caddy 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 caddy
import (
"encoding/json"
"io"
)
func ExampleContext_LoadModule() {
// this whole first part is just setting up for the example;
// note the struct tags - very important; we specify inline_key
// because that is the only way to know the module name
var ctx Context
myStruct := &struct {
// This godoc comment will appear in module documentation.
GuestModuleRaw json.RawMessage `json:"guest_module,omitempty" caddy:"namespace=example inline_key=name"`
// this is where the decoded module will be stored; in this
// example, we pretend we need an io.Writer but it can be
// any interface type that is useful to you
guestModule io.Writer
}{
GuestModuleRaw: json.RawMessage(`{"name":"module_name","foo":"bar"}`),
}
// if a guest module is provided, we can load it easily
if myStruct.GuestModuleRaw != nil {
mod, err := ctx.LoadModule(myStruct, "GuestModuleRaw")
if err != nil {
// you'd want to actually handle the error here
// return fmt.Errorf("loading guest module: %v", err)
}
// mod contains the loaded and provisioned module,
// it is now ready for us to use
myStruct.guestModule = mod.(io.Writer)
}
// use myStruct.guestModule from now on
}
func ExampleContext_LoadModule_array() {
// this whole first part is just setting up for the example;
// note the struct tags - very important; we specify inline_key
// because that is the only way to know the module name
var ctx Context
myStruct := &struct {
// This godoc comment will appear in module documentation.
GuestModulesRaw []json.RawMessage `json:"guest_modules,omitempty" caddy:"namespace=example inline_key=name"`
// this is where the decoded module will be stored; in this
// example, we pretend we need an io.Writer but it can be
// any interface type that is useful to you
guestModules []io.Writer
}{
GuestModulesRaw: []json.RawMessage{
json.RawMessage(`{"name":"module1_name","foo":"bar1"}`),
json.RawMessage(`{"name":"module2_name","foo":"bar2"}`),
},
}
// since our input is []json.RawMessage, the output will be []interface{}
mods, err := ctx.LoadModule(myStruct, "GuestModulesRaw")
if err != nil {
// you'd want to actually handle the error here
// return fmt.Errorf("loading guest modules: %v", err)
}
for _, mod := range mods.([]interface{}) {
myStruct.guestModules = append(myStruct.guestModules, mod.(io.Writer))
}
// use myStruct.guestModules from now on
}
func ExampleContext_LoadModule_map() {
// this whole first part is just setting up for the example;
// note the struct tags - very important; we don't specify
// inline_key because the map key is the module name
var ctx Context
myStruct := &struct {
// This godoc comment will appear in module documentation.
GuestModulesRaw ModuleMap `json:"guest_modules,omitempty" caddy:"namespace=example"`
// this is where the decoded module will be stored; in this
// example, we pretend we need an io.Writer but it can be
// any interface type that is useful to you
guestModules map[string]io.Writer
}{
GuestModulesRaw: ModuleMap{
"module1_name": json.RawMessage(`{"foo":"bar1"}`),
"module2_name": json.RawMessage(`{"foo":"bar2"}`),
},
}
// since our input is map[string]json.RawMessage, the output will be map[string]interface{}
mods, err := ctx.LoadModule(myStruct, "GuestModulesRaw")
if err != nil {
// you'd want to actually handle the error here
// return fmt.Errorf("loading guest modules: %v", err)
}
for modName, mod := range mods.(map[string]interface{}) {
myStruct.guestModules[modName] = mod.(io.Writer)
}
// use myStruct.guestModules from now on
}

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