Merge pull request #7 from ChrisTrenkamp/v0.9.10

Added support for unmarshalling results into structs and slices.
ChrisTrenkamp · Aug 26, 2023 · 77f3855 · 77f3855
2 parents 333462d + fbe9b5b
commit 77f3855
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diff --git a/README.md b/README.md
@@ -126,6 +126,84 @@ func main() {
 }
 ```
 
+## Unmarshal result into a struct
+
+```go
+package main
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/ChrisTrenkamp/xsel/exec"
+	"github.com/ChrisTrenkamp/xsel/grammar"
+	"github.com/ChrisTrenkamp/xsel/node"
+	"github.com/ChrisTrenkamp/xsel/parser"
+	"github.com/ChrisTrenkamp/xsel/store"
+)
+
+func main() {
+	xml := `
+<Root xmlns="http://www.adventure-works.com">
+	<Customers>
+		<Customer CustomerID="GREAL">
+			<CompanyName>Great Lakes Food Market</CompanyName>
+			<ContactName>Howard Snyder</ContactName>
+			<ContactTitle>Marketing Manager</ContactTitle>
+			<FullAddress>
+				<Address>2732 Baker Blvd.</Address>
+				<City>Eugene</City>
+				<Region>OR</Region>
+			</FullAddress>
+		</Customer>
+		<Customer CustomerID="HUNGC">
+		  <CompanyName>Hungry Coyote Import Store</CompanyName>
+		  <ContactName>Yoshi Latimer</ContactName>
+		  <FullAddress>
+			<Address>City Center Plaza 516 Main St.</Address>
+			<City>Walla Walla</City>
+			<Region>WA</Region>
+		  </FullAddress>
+		</Customer>
+	</Customers>
+</Root>
+`
+
+	type Address struct {
+		Address string `xsel:"NS:Address"`
+		City    string `xsel:"NS:City"`
+		Region  string `xsel:"NS:Region"`
+	}
+
+	type Customer struct {
+		Id          string  `xsel:"@CustomerID"`
+		Name        string  `xsel:"NS:CompanyName"`
+		ContactName string  `xsel:"NS:ContactName"`
+		Address     Address `xsel:"NS:FullAddress"`
+	}
+
+	type Customers struct {
+		Customers []Customer `xsel:"NS:Customers/NS:Customer"`
+	}
+
+	contextSettings := func(c *exec.ContextSettings) {
+		c.NamespaceDecls["NS"] = "http://www.adventure-works.com"
+	}
+
+	xpath := grammar.MustBuild(`/NS:Root`)
+	parser := parser.ReadXml(bytes.NewBufferString(xml))
+	cursor, _ := store.CreateInMemory(parser)
+	result, _ := exec.Exec(cursor, &xpath, contextSettings)
+
+	customers := Customers{}
+	exec.Unmarshal(result, &customers, contextSettings) // Remember to check for errors
+
+	fmt.Printf("%+v\n", customers)
+	//{Customers:[{Id:GREAL Name:Great Lakes Food Market ContactName:Howard Snyder Address:{Address:2732 Baker Blvd. City:Eugene Region:OR}}
+	// {Id:HUNGC Name:Hungry Coyote Import Store ContactName:Yoshi Latimer Address:{Address:City Center Plaza 516 Main St. City:Walla Walla Region:WA}}]}
+}
+```
+
 ## Extensible
 
 `xsel` supplies an XML parser (using the `encoding/xml` package) out of the box, but the XPath logic does not depend directly on XML.  It instead depends on the interfaces defined in the [node](https://pkg.go.dev/github.com/ChrisTrenkamp/xsel/node) and [store](https://pkg.go.dev/github.com/ChrisTrenkamp/xsel/store) packages.  This means it's possible to use `xsel` for querying against non-XML documents.  The [parser](https://pkg.go.dev/github.com/ChrisTrenkamp/xsel/parser) package supplies methods for parsing XML, HTML, and JSON documents.

diff --git a/exec/doc_test.go b/exec/doc_test.go
@@ -97,3 +97,64 @@ func ExampleExec_custom_variables() {
 
 	fmt.Println(result)
 }
+
+func ExampleExec_unmarshal() {
+	xml := `
+<Root xmlns="http://www.adventure-works.com">
+	<Customers>
+		<Customer CustomerID="GREAL">
+			<CompanyName>Great Lakes Food Market</CompanyName>
+			<ContactName>Howard Snyder</ContactName>
+			<ContactTitle>Marketing Manager</ContactTitle>
+			<FullAddress>
+				<Address>2732 Baker Blvd.</Address>
+				<City>Eugene</City>
+				<Region>OR</Region>
+			</FullAddress>
+		</Customer>
+		<Customer CustomerID="HUNGC">
+		  <CompanyName>Hungry Coyote Import Store</CompanyName>
+		  <ContactName>Yoshi Latimer</ContactName>
+		  <FullAddress>
+			<Address>City Center Plaza 516 Main St.</Address>
+			<City>Walla Walla</City>
+			<Region>WA</Region>
+		  </FullAddress>
+		</Customer>
+	</Customers>
+</Root>
+`
+
+	type Address struct {
+		Address string `xsel:"NS:Address"`
+		City    string `xsel:"NS:City"`
+		Region  string `xsel:"NS:Region"`
+	}
+
+	type Customer struct {
+		Id          string  `xsel:"@CustomerID"`
+		Name        string  `xsel:"NS:CompanyName"`
+		ContactName string  `xsel:"NS:ContactName"`
+		Address     Address `xsel:"NS:FullAddress"`
+	}
+
+	type Customers struct {
+		Customers []Customer `xsel:"NS:Customers/NS:Customer"`
+	}
+
+	contextSettings := func(c *exec.ContextSettings) {
+		c.NamespaceDecls["NS"] = "http://www.adventure-works.com"
+	}
+
+	xpath := grammar.MustBuild(`/NS:Root`)
+	parser := parser.ReadXml(bytes.NewBufferString(xml))
+	cursor, _ := store.CreateInMemory(parser)
+	result, _ := exec.Exec(cursor, &xpath, contextSettings)
+
+	customers := Customers{}
+	exec.Unmarshal(result, &customers, contextSettings) // Remember to check for errors
+
+	fmt.Printf("%+v\n", customers)
+	//{Customers:[{Id:GREAL Name:Great Lakes Food Market ContactName:Howard Snyder Address:{Address:2732 Baker Blvd. City:Eugene Region:OR}}
+	// {Id:HUNGC Name:Hungry Coyote Import Store ContactName:Yoshi Latimer Address:{Address:City Center Plaza 516 Main St. City:Walla Walla Region:WA}}]}
+}
diff --git a/exec/exec_test.go b/exec/exec_test.go
@@ -3,6 +3,7 @@ package exec
 import (
 	"bytes"
 	"math"
+	"reflect"
 	"testing"
 
 	"github.com/ChrisTrenkamp/xsel/grammar"
@@ -1550,3 +1551,80 @@ func TestHtmlDocument(t *testing.T) {
 		t.Error("bad href value")
 	}
 }
+
+func TestUnmarshal(t *testing.T) {
+	type SubUnmarshalTarget struct {
+		A      *string `xsel:"a"`
+		Battr  bool    `xsel:"b/@attr"`
+		Ignore string
+	}
+
+	type SliceUnmarshalTarget struct {
+		Elem string `xsel:"."`
+	}
+
+	type UnmarshalTarget struct {
+		Text        string                   `xsel:"normalize-space(text())"`
+		Attr        float32                  `xsel:"node/@attr"`
+		Attr64      float64                  `xsel:"node/@attr"`
+		Subfield    **SubUnmarshalTarget     `xsel:"node"`
+		Slice       *[]*SliceUnmarshalTarget `xsel:"slice/elem"`
+		StringSlice []string                 `xsel:"slice/elem"`
+		Uint8       uint8                    `xsel:"slice/elem[1]"`
+		Int8        int8                     `xsel:"slice/elem[1]"`
+		Uint16      uint16                   `xsel:"slice/elem[1]"`
+		Int16       int16                    `xsel:"slice/elem[1]"`
+		Uint32      uint32                   `xsel:"slice/elem[1]"`
+		Int32       int32                    `xsel:"slice/elem[1]"`
+		Uint64      uint64                   `xsel:"slice/elem[1]"`
+		Int64       int64                    `xsel:"slice/elem[1]"`
+	}
+
+	xml := `
+<root>
+	foo
+	<node attr="3.14">
+		<a>a</a>
+		<b attr="true"/>
+	</node>
+	<slice>
+		<elem>1</elem>
+		<elem>2</elem>
+		<elem>3</elem>
+	</slice>
+</root>
+`
+	nodes := execXmlNodes(t, "/root", xml)
+	target := UnmarshalTarget{}
+
+	if err := Unmarshal(nodes, &target); err != nil {
+		t.Error(err)
+	}
+
+	a := "a"
+	subExpected := &SubUnmarshalTarget{
+		A:     &a,
+		Battr: true,
+	}
+	sliceResults := []*SliceUnmarshalTarget{{"1"}, {"2"}, {"3"}}
+	expected := UnmarshalTarget{
+		Text:        "foo",
+		Attr:        3.14,
+		Attr64:      3.14,
+		Subfield:    &subExpected,
+		Slice:       &sliceResults,
+		StringSlice: []string{"1", "2", "3"},
+		Uint8:       1,
+		Int8:        1,
+		Uint16:      1,
+		Int16:       1,
+		Uint32:      1,
+		Int32:       1,
+		Uint64:      1,
+		Int64:       1,
+	}
+
+	if !reflect.DeepEqual(expected, target) {
+		t.Error("incorrect result")
+	}
+}