document.SetConformance is added with an example (unidoc#399)

* document.SetConformance is added with an example

* SetStrict is added as shortcut

* 2020

* preserve conformance attr

* fix

_examples/document/set-strict/main.go

@@ -0,0 +1,21 @@
+// Copyright 2020 FoxyUtils ehf. All rights reserved.
+
+package main
+
+import (
+	"github.com/unidoc/unioffice/document"
+	st "github.com/unidoc/unioffice/schema/soo/ofc/sharedTypes"
+)
+
+func main() {
+	doc, err := document.Open("document.docx")
+	if err != nil {
+		panic(err)
+	}
+	doc.SetStrict(false) // document will be saved as Word document (this is a default option for new files)
+	doc.SaveToFile("conformance_transitional.docx")
+	doc.SetStrict(true) // document will be saved in the Strict mode
+	doc.SaveToFile("conformance_strict.docx")
+	doc.SetConformance(st.ST_ConformanceClassUnset) // Conformance attribute will be unset, which also leads to saving as Word document
+	doc.SaveToFile("conformance_unset.docx")
+}

document/document.go

@@ -665,6 +665,7 @@ func Read(r io.ReaderAt, size int64) (*Document, error) {
 		doc.createCustomProperties()
 	}
 
+	ca := doc.x.ConformanceAttr
 	decMap := zippkg.DecodeMap{}
 	decMap.SetOnNewRelationshipFunc(doc.onNewRelationship)
 	// we should discover all contents by starting with these two files
@@ -673,6 +674,7 @@ func Read(r io.ReaderAt, size int64) (*Document, error) {
 	if err := decMap.Decode(files); err != nil {
 		return nil, err
 	}
+	doc.x.ConformanceAttr = ca
 
 	for _, f := range files {
 		if f == nil {
@@ -1150,6 +1152,24 @@ func (d Document) Bookmarks() []Bookmark {
 	return ret
 }
 
+// SetConformance sets conformance attribute of the document
+// as one of these values from github.com/unidoc/unioffice/schema/soo/ofc/sharedTypes:
+// ST_ConformanceClassUnset, ST_ConformanceClassStrict or ST_ConformanceClassTransitional.
+func (d Document) SetConformance(conformanceAttr st.ST_ConformanceClass) {
+	d.x.ConformanceAttr = conformanceAttr
+}
+
+// SetStrict is a shortcut for document.SetConformance,
+// as one of these values from github.com/unidoc/unioffice/schema/soo/ofc/sharedTypes:
+// ST_ConformanceClassUnset, ST_ConformanceClassStrict or ST_ConformanceClassTransitional.
+func (d Document) SetStrict(strict bool) {
+	if strict {
+		d.x.ConformanceAttr = st.ST_ConformanceClassStrict
+	} else {
+		d.x.ConformanceAttr = st.ST_ConformanceClassTransitional
+	}
+}
+
 func getBool(onOff *wml.CT_OnOff) bool {
 	return onOff != nil
 }

go.mod

@@ -1 +1,3 @@
 module github.com/unidoc/unioffice
+
+go 1.12