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Diffstat (limited to 'caddyconfig/configadapters.go')
-rw-r--r-- | caddyconfig/configadapters.go | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/caddyconfig/configadapters.go b/caddyconfig/configadapters.go new file mode 100644 index 0000000..6e5d530 --- /dev/null +++ b/caddyconfig/configadapters.go @@ -0,0 +1,113 @@ +// 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 caddyconfig + +import ( + "encoding/json" + "fmt" +) + +// Adapter is a type which can adapt a configuration to Caddy JSON. +// It returns the results and any warnings, or an error. +type Adapter interface { + Adapt(body []byte, options map[string]string) ([]byte, []Warning, error) +} + +// Warning represents a warning or notice related to conversion. +type Warning struct { + File string + Line int + Directive string + Message string +} + +// JSON encodes val as JSON, returning it as a json.RawMessage. Any +// marshaling errors (which are highly unlikely with correct code) +// are converted to warnings. This is convenient when filling config +// structs that require a json.RawMessage, without having to worry +// about errors. +func JSON(val interface{}, warnings *[]Warning) json.RawMessage { + b, err := json.Marshal(val) + if err != nil { + if warnings != nil { + *warnings = append(*warnings, Warning{Message: err.Error()}) + } + return nil + } + return b +} + +// JSONModuleObject is like JSON, except it marshals val into a JSON object +// and then adds a key to that object named fieldName with the value fieldVal. +// This is useful for JSON-encoding module values where the module name has to +// be described within the object by a certain key; for example, +// "responder": "file_server" for a file server HTTP responder. The val must +// encode into a map[string]interface{} (i.e. it must be a struct or map), +// and any errors are converted into warnings, so this can be conveniently +// used when filling a struct. For correct code, there should be no errors. +func JSONModuleObject(val interface{}, fieldName, fieldVal string, warnings *[]Warning) json.RawMessage { + // encode to a JSON object first + enc, err := json.Marshal(val) + if err != nil { + if warnings != nil { + *warnings = append(*warnings, Warning{Message: err.Error()}) + } + return nil + } + + // then decode the object + var tmp map[string]interface{} + err = json.Unmarshal(enc, &tmp) + if err != nil { + if warnings != nil { + *warnings = append(*warnings, Warning{Message: err.Error()}) + } + return nil + } + + // so we can easily add the module's field with its appointed value + tmp[fieldName] = fieldVal + + // then re-marshal as JSON + result, err := json.Marshal(tmp) + if err != nil { + if warnings != nil { + *warnings = append(*warnings, Warning{Message: err.Error()}) + } + return nil + } + + return result +} + +// JSONIndent is used to JSON-marshal the final resulting Caddy +// configuration in a consistent, human-readable way. +func JSONIndent(val interface{}) ([]byte, error) { + return json.MarshalIndent(val, "", "\t") +} + +func RegisterAdapter(name string, adapter Adapter) error { + if _, ok := configAdapters[name]; ok { + return fmt.Errorf("%s: already registered", name) + } + configAdapters[name] = adapter + return nil +} + +func GetAdapter(name string) Adapter { + return configAdapters[name] +} + +var configAdapters = make(map[string]Adapter) |