cxpath

README

cxpath - a programmer's friendly interface to XPath

Experimental, not ready for production use

With cxpath you can access XML files via XPath 2.0 in a Go friendly matter.

<a:root xmlns:a="anamespace">
  <a:sub>text</a:sub>
</a:root>

package main

import (
	"fmt"
	"log"

	"github.com/speedata/cxpath"
)

func dothings() error {
	ctx, err := cxpath.NewFromFile("myfile.xml")
	if err != nil {
		return err
	}
	// for XPath queries
	ctx.SetNamespace("a", "anamespace")
	root := ctx.Root()
	// prints 'root'
	fmt.Println(root.Eval("local-name()"))
	// prints sub
	fmt.Println(root.Eval("local-name(a:sub)"))
	// prints anamespace
	fmt.Println(root.Eval("namespace-uri(a:sub)"))
	sub := root.Eval("a:sub")
	for cp := range sub.Each("string-to-codepoints(.)") {
		// prints 116, 101, 120, 116 - the codepoints for 'text'
		fmt.Println(cp)
	}
	return nil
}

func main() {
	if err := dothings(); err != nil {
		log.Fatal(err)
	}
}

Installation

go get github.com/speedata/cxpath

Documentation

Index

• type Context
  • func NewFromFile(filename string) (*Context, error)
  • func NewFromReader(r io.Reader) (*Context, error)
  • func (ctx *Context) Bool() bool
  • func (ctx *Context) Each(eval string) iter.Seq[*Context]
  • func (ctx *Context) Eval(eval string) *Context
  • func (ctx *Context) Int() int
  • func (ctx *Context) Root() *Context
  • func (ctx *Context) SetNamespace(prefix, uri string) *Context
  • func (ctx *Context) String() string

Types

type Context

type Context struct {
	P     *goxpath.Parser
	Seq   goxpath.Sequence
	Error error
}

A Context stores the current state of the XPath parser.

func NewFromFile

func NewFromFile(filename string) (*Context, error)

NewFromFile returns a new context from a file name.

func NewFromReader

func NewFromReader(r io.Reader) (*Context, error)

NewFromReader returns a new context from a reader.

func (*Context) Bool

func (ctx *Context) Bool() bool

Bool returns the boolean value of the sequence.

func (*Context) Each

func (ctx *Context) Each(eval string) iter.Seq[*Context]

Each can be used as an iterator which returns a Context for each item in the resulting sequence.

func (*Context) Eval

func (ctx *Context) Eval(eval string) *Context

Eval executes the given XPath expression relative to the current context. It returns a new Context, so the old one is still available for further use.

func (*Context) Int

func (ctx *Context) Int() int

Int returns the number value as an integer

func (*Context) Root

func (ctx *Context) Root() *Context

Root returns the top most element of the XML file.

func (*Context) SetNamespace

func (ctx *Context) SetNamespace(prefix, uri string) *Context

SetNamespace sets a prefix/URI pair for XPath queries.

func (*Context) String

func (ctx *Context) String() string