yq/pkg/yqlib/printer.go
Mike Farah 23d3d962e0 Refactored decoder responsibilities
- improved comment handling
- yaml decoder now responsible for leading content work around
2022-10-28 14:05:20 +11:00

168 lines
4.2 KiB
Go

package yqlib
import (
"bufio"
"container/list"
"fmt"
"io"
"regexp"
yaml "gopkg.in/yaml.v3"
)
type Printer interface {
PrintResults(matchingNodes *list.List) error
PrintedAnything() bool
//e.g. when given a front-matter doc, like jekyll
SetAppendix(reader io.Reader)
}
type PrinterOutputFormat uint32
const (
YamlOutputFormat = 1 << iota
JSONOutputFormat
PropsOutputFormat
CSVOutputFormat
TSVOutputFormat
XMLOutputFormat
Base64OutputFormat
)
func OutputFormatFromString(format string) (PrinterOutputFormat, error) {
switch format {
case "yaml", "y":
return YamlOutputFormat, nil
case "json", "j":
return JSONOutputFormat, nil
case "props", "p":
return PropsOutputFormat, nil
case "csv", "c":
return CSVOutputFormat, nil
case "tsv", "t":
return TSVOutputFormat, nil
case "xml", "x":
return XMLOutputFormat, nil
default:
return 0, fmt.Errorf("unknown format '%v' please use [yaml|json|props|csv|tsv|xml]", format)
}
}
type resultsPrinter struct {
encoder Encoder
printerWriter PrinterWriter
firstTimePrinting bool
previousDocIndex uint
previousFileIndex int
printedMatches bool
treeNavigator DataTreeNavigator
appendixReader io.Reader
}
func NewPrinter(encoder Encoder, printerWriter PrinterWriter) Printer {
return &resultsPrinter{
encoder: encoder,
printerWriter: printerWriter,
firstTimePrinting: true,
treeNavigator: NewDataTreeNavigator(),
}
}
func (p *resultsPrinter) SetAppendix(reader io.Reader) {
p.appendixReader = reader
}
func (p *resultsPrinter) PrintedAnything() bool {
return p.printedMatches
}
func (p *resultsPrinter) printNode(node *yaml.Node, writer io.Writer) error {
p.printedMatches = p.printedMatches || (node.Tag != "!!null" &&
(node.Tag != "!!bool" || node.Value != "false"))
return p.encoder.Encode(writer, node)
}
func (p *resultsPrinter) PrintResults(matchingNodes *list.List) error {
log.Debug("PrintResults for %v matches", matchingNodes.Len())
if matchingNodes.Len() == 0 {
log.Debug("no matching results, nothing to print")
return nil
}
if !p.encoder.CanHandleAliases() {
explodeOp := Operation{OperationType: explodeOpType}
explodeNode := ExpressionNode{Operation: &explodeOp}
context, err := p.treeNavigator.GetMatchingNodes(Context{MatchingNodes: matchingNodes}, &explodeNode)
if err != nil {
return err
}
matchingNodes = context.MatchingNodes
}
if p.firstTimePrinting {
node := matchingNodes.Front().Value.(*CandidateNode)
p.previousDocIndex = node.Document
p.previousFileIndex = node.FileIndex
p.firstTimePrinting = false
}
for el := matchingNodes.Front(); el != nil; el = el.Next() {
mappedDoc := el.Value.(*CandidateNode)
log.Debug("-- print sep logic: p.firstTimePrinting: %v, previousDocIndex: %v, mappedDoc.Document: %v", p.firstTimePrinting, p.previousDocIndex, mappedDoc.Document)
log.Debug("%v", NodeToString(mappedDoc))
writer, errorWriting := p.printerWriter.GetWriter(mappedDoc)
if errorWriting != nil {
return errorWriting
}
commentsStartWithSepExp := regexp.MustCompile(`^\$yqDocSeperator\$`)
commentStartsWithSeparator := commentsStartWithSepExp.MatchString(mappedDoc.LeadingContent)
if (p.previousDocIndex != mappedDoc.Document || p.previousFileIndex != mappedDoc.FileIndex) && !commentStartsWithSeparator {
if err := p.encoder.PrintDocumentSeparator(writer); err != nil {
return err
}
}
if err := p.encoder.PrintLeadingContent(writer, mappedDoc.LeadingContent); err != nil {
return err
}
if err := p.printNode(mappedDoc.Node, writer); err != nil {
return err
}
if err := p.encoder.PrintLeadingContent(writer, mappedDoc.TrailingContent); err != nil {
return err
}
p.previousDocIndex = mappedDoc.Document
if err := writer.Flush(); err != nil {
return err
}
log.Debugf("done printing results")
}
// what happens if I remove output format check?
if p.appendixReader != nil {
writer, err := p.printerWriter.GetWriter(nil)
if err != nil {
return err
}
log.Debug("Piping appendix reader...")
betterReader := bufio.NewReader(p.appendixReader)
_, err = io.Copy(writer, betterReader)
if err != nil {
return err
}
if err := writer.Flush(); err != nil {
return err
}
}
return nil
}