Refactoring Outputs to implement a standard interface #15
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,13 @@ | ||
| package output | ||
|
|
||
| import ( | ||
| "fmt" | ||
| ) | ||
|
|
||
| type InvalidOutput struct { | ||
| Config Config | ||
| } | ||
|
|
||
| func (o *InvalidOutput) GenerateOutput(elements interface{}) (string, error) { | ||
| return "", fmt.Errorf("Unrecognized output format: %s", o.Config.Format) | ||
| } | ||
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,30 @@ | ||
| package output | ||
|
|
||
| import ( | ||
| "encoding/json" | ||
| "fmt" | ||
| ) | ||
|
|
||
| type JSONOutput struct { | ||
| Config Config | ||
| } | ||
|
|
||
| func (o *JSONOutput) GenerateOutput(elements interface{}) (string, error) { | ||
| if _, ok := elements.([]interface{}); ok { | ||
| if j, err := json.MarshalIndent(elements, " ", " "); err != nil { | ||
| return "", err | ||
| } else { | ||
| return string(j), nil | ||
| } | ||
| } else { | ||
| if _, ok := elements.(map[string]interface{}); ok { | ||
| if j, err := json.MarshalIndent(elements, " ", " "); err != nil { | ||
| return "", err | ||
| } else { | ||
| return string(j), nil | ||
| } | ||
| } else { | ||
| return fmt.Sprintf("%s", elements), nil | ||
| } | ||
| } | ||
| } |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,11 +1,8 @@ | ||
| package output | ||
|
|
||
| type OutputBuilder interface { | ||
|
Contributor
There was a problem hiding this comment. ah, so we are declaring a public interface here... This is intended to communicate to implementors of new output types that their output struct, say
Owner
Author
There was a problem hiding this comment. I believe implementations have to match exactly the same number of methods as well as exact input and output types. In this case, if a struct would implement anything other than GenerateOutput, it would no longer conform to the interface.
Contributor
There was a problem hiding this comment. I think 'struct typing' allows any struct that minimally implements the interface, but may implement methods outside the interface, to be used as the interface. For example: https://play.golang.org/p/2JS1qC9kca
Owner
Author
There was a problem hiding this comment. Ah - I did not know that :) |
||
| GenerateOutput(interface{}) (string, error) | ||
| } | ||
|
|
||
| type Config struct { | ||
| Format string | ||
|
|
@@ -20,111 +17,21 @@ func (o *Output) Generate(elements interface{}) (string, error) { | |
| return "", nil | ||
| } | ||
|
|
||
| var v OutputBuilder | ||
| switch o.Config.Format { | ||
| case "json": | ||
| v = &JSONOutput{ | ||
| Config: o.Config, | ||
| } | ||
| case "shell": | ||
| v = &ShellOutput{ | ||
| Config: o.Config, | ||
| } | ||
| default: | ||
| v = &InvalidOutput{ | ||
|
Contributor
There was a problem hiding this comment. Safe zero value/Null Object pattern. Makes sense. |
||
| Config: o.Config, | ||
| } | ||
| } | ||
|
|
||
| return v.GenerateOutput(elements) | ||
| } | ||
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,90 @@ | ||
| package output | ||
|
|
||
| import ( | ||
| "fmt" | ||
| "sort" | ||
| "strings" | ||
| ) | ||
|
|
||
| type ShellOutput struct { | ||
| Config Config | ||
| } | ||
|
|
||
| func (o *ShellOutput) GenerateOutput(elements interface{}) (string, error) { | ||
| var keys []string | ||
| var output string | ||
|
|
||
| parsed := make(map[string]string) | ||
| _, _, parsed = parseElementsForShell("elements", elements, parsed) | ||
|
|
||
| for k := range parsed { | ||
| keys = append(keys, k) | ||
| } | ||
|
|
||
| sort.Strings(keys) | ||
|
|
||
| for _, k := range keys { | ||
| output = fmt.Sprintf("%s%s=\"%s\"\n", output, k, parsed[k]) | ||
| } | ||
|
|
||
| return output, nil | ||
| } | ||
|
|
||
| func parseElementsForShell(label string, elements interface{}, parsed map[string]string) (string, interface{}, map[string]string) { | ||
| var e interface{} | ||
| switch elements.(type) { | ||
| case map[string]interface{}: | ||
| for key, subElements := range elements.(map[string]interface{}) { | ||
| l := fmt.Sprintf("%s_%s", label, sanitizeKeyForShell(key)) | ||
| _, e, parsed = parseElementsForShell(l, subElements, parsed) | ||
| } | ||
| case []interface{}: | ||
| for i, subElements := range elements.([]interface{}) { | ||
| l := fmt.Sprintf("%s_%d", label, i) | ||
| _, e, parsed = parseElementsForShell(l, subElements, parsed) | ||
| } | ||
| default: | ||
| parsed[label] = fmt.Sprintf("%v", elements) | ||
| return label, nil, parsed | ||
| } | ||
|
|
||
| return label, e, parsed | ||
| } | ||
|
|
||
| func sanitizeKeyForShell(key string) string { | ||
| // replace non-compliant shell characters with underscores, | ||
| // per IEEE Std 1003.1-2001 | ||
| r := strings.NewReplacer( | ||
| "`", "_", | ||
| "~", "_", | ||
| "!", "_", | ||
| "@", "_", | ||
| "#", "_", | ||
| "$", "_", | ||
| "%", "_", | ||
| "^", "_", | ||
| "&", "_", | ||
| "*", "_", | ||
| "(", "_", | ||
| ")", "_", | ||
| "-", "_", | ||
| "+", "_", | ||
| "=", "_", | ||
| "{", "_", | ||
| "}", "_", | ||
| "[", "_", | ||
| "]", "_", | ||
| "|", "_", | ||
| ":", "_", | ||
| ";", "_", | ||
| "'", "_", | ||
| "\"", "_", | ||
| "/", "_", | ||
| "?", "_", | ||
| ",", "_", | ||
| ".", "_", | ||
| "<", "_", | ||
| ">", "_", | ||
| ) | ||
| return r.Replace(key) | ||
| } |
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
So, here you're 'struct typing', rather than explicitly declaring an
type Outputer interface, right?There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Correct.