Fix textual access mode inference with FXL (#81)

pkg/parser/epub/factory.go

@@ -73,10 +73,9 @@ func (f PublicationFactory) Create() manifest.Manifest {
 			readingOrder = append(readingOrder, f.computeLink(item, []string{}))
 		}
 	}
-	readingOrderAllIds := f.computeIdsWithFallbacks(readingOrderIds)
 	var resourceItems []Item
 	for _, item := range mani {
-		if !extensions.Contains(readingOrderAllIds, item.ID) {
+		if !extensions.Contains(readingOrderIds, item.ID) {
 			resourceItems = append(resourceItems, item)
 		}
 	}
@@ -144,40 +143,6 @@ func mapEPUBLink(link EPUBLink) manifest.Link {
 	return l
 }
 
-// Recursively find the ids of the fallback items in [items]
-func (f PublicationFactory) computeIdsWithFallbacks(ids []string) []string {
-	var fallbackIds []string
-	for _, id := range ids {
-		for _, v := range f.computeFallbackChain(id) {
-			if !extensions.Contains(fallbackIds, v) {
-				fallbackIds = append(fallbackIds, v)
-			}
-		}
-	}
-	return fallbackIds
-}
-
-// Compute the ids contained in the fallback chain of [item]
-func (f PublicationFactory) computeFallbackChain(id string) []string {
-	// The termination has already been checked while computing links
-	var ids []string
-	item, ok := f.itemById[id]
-	if !ok {
-		return ids
-	}
-	if item.ID != "" {
-		ids = append(ids, item.ID)
-	}
-	if item.fallback != "" {
-		for _, v := range f.computeFallbackChain(item.fallback) {
-			if !extensions.Contains(ids, v) {
-				ids = append(ids, v)
-			}
-		}
-	}
-	return ids
-}
-
 // Compute a Publication [Link] for an epub [Item] and its fallbacks
 func (f PublicationFactory) computeLink(item Item, fallbackChain []string) manifest.Link {
 	itemref, _ := f.itemrefByIdref[item.ID]

pkg/streamer/a11y_infer.go

@@ -39,10 +39,14 @@ func inferA11yMetadataFromManifest(mf manifest.Manifest) *manifest.A11y {
 	// Inferred textual if the publication is partially or fully accessible
 	// (WCAG A or above).
 	isTextual := conformsToWCAGA
-	if !isTextual {
-		// ... or if the publication does not contain any image, audio or video
-		// resource (inspect "resources" and "readingOrder" in RWPM), or if the
-		// only image available can be identified as a cover.
+
+	// ... or if a reflowable EPUB does not contain any image, audio or
+	// video resource (inspect "resources" and "readingOrder" in RWPM), or
+	// if the only image available can be identified as a cover.
+	if !isTextual &&
+		mf.ConformsTo(manifest.ProfileEPUB) &&
+		mf.Metadata.Presentation != nil &&
+		*mf.Metadata.Presentation.Layout == manifest.EPUBLayoutReflowable {
 		isTextual = true
 		for _, link := range allResources {
 			mt := link.MediaType()

pkg/streamer/a11y_infer_test.go

@@ -14,7 +14,9 @@ func TestReturnsAdditionalInferredA11yMetadata(t *testing.T) {
 
 	m := manifest.Manifest{
 		Metadata: manifest.Metadata{
+			ConformsTo:    manifest.Profiles{manifest.ProfileEPUB},
 			Accessibility: &a11y,
+			Presentation:  newEPUBPresentation(manifest.EPUBLayoutReflowable),
 		},
 		ReadingOrder: []manifest.Link{
 			newLink(mediatype.HTML, "html"),
@@ -91,7 +93,7 @@ func TestInferTextualAccessModeAndAccessModeSufficientFromProfile(t *testing.T)
 	test(manifest.EPUBA11y10WCAG20AAA)
 }
 
-// Or if the publication does not contain any image, audio or video resource
+// Or if a reflowable EPUB does not contain any image, audio or video resource
 // (inspect "resources" and "readingOrder" in RWPM)
 func TestInferTextualAccessModeAndAccessModeSufficientFromLackOfMedia(t *testing.T) {
 	testManifest := func(contains bool, m manifest.Manifest) {
@@ -113,7 +115,11 @@ func TestInferTextualAccessModeAndAccessModeSufficientFromLackOfMedia(t *testing
 
 	testReadingOrder := func(contains bool, mt mediatype.MediaType, extension string) {
 		testManifest(contains, manifest.Manifest{
-			Metadata:        manifest.Metadata{Accessibility: &a11y},
+			Metadata: manifest.Metadata{
+				ConformsTo:    manifest.Profiles{manifest.ProfileEPUB},
+				Accessibility: &a11y,
+				Presentation:  newEPUBPresentation(manifest.EPUBLayoutReflowable),
+			},
 			ReadingOrder:    []manifest.Link{newLink(mt, extension)},
 			TableOfContents: []manifest.Link{newLink(mt, extension)},
 		})
@@ -127,7 +133,12 @@ func TestInferTextualAccessModeAndAccessModeSufficientFromLackOfMedia(t *testing
 
 	testResources := func(contains bool, mt mediatype.MediaType, extension string) {
 		testManifest(contains, manifest.Manifest{
-			Metadata:        manifest.Metadata{Accessibility: &a11y},
+			Metadata: manifest.Metadata{
+				ConformsTo:    manifest.Profiles{manifest.ProfileEPUB},
+				Accessibility: &a11y,
+				Presentation:  newEPUBPresentation(manifest.EPUBLayoutReflowable),
+			},
+			ReadingOrder:    []manifest.Link{newLink(mt, extension)},
 			Resources:       []manifest.Link{newLink(mt, extension)},
 			TableOfContents: []manifest.Link{newLink(mt, extension)},
 		})
@@ -140,10 +151,35 @@ func TestInferTextualAccessModeAndAccessModeSufficientFromLackOfMedia(t *testing
 	testResources(false, mediatype.PDF, "pdf")
 }
 
+// ... but not for FXL EPUB
+func TestDontInferTextualAccessModeAndAccessModeSufficientFromLackOfMediaForFXL(t *testing.T) {
+	a11y := manifest.NewA11y()
+	a11y.ConformsTo = []manifest.A11yProfile{"unknown"}
+
+	m := manifest.Manifest{
+		Metadata: manifest.Metadata{
+			ConformsTo:    manifest.Profiles{manifest.ProfileEPUB},
+			Accessibility: &a11y,
+			Presentation:  newEPUBPresentation(manifest.EPUBLayoutFixed),
+		},
+		ReadingOrder:    []manifest.Link{newLink(mediatype.HTML, "html")},
+		TableOfContents: []manifest.Link{newLink(mediatype.HTML, "html")},
+	}
+
+	res := inferA11yMetadataFromManifest(m)
+	assert.NotNil(t, res)
+	ams := []manifest.A11yPrimaryAccessMode{manifest.A11yPrimaryAccessModeTextual}
+	assert.NotContains(t, res.AccessModes, manifest.A11yAccessModeTextual)
+	assert.NotContains(t, res.AccessModesSufficient, ams)
+}
+
 // If the publication contains only references to audio resources (inspect "resources" and "readingOrder" in RWPM)
 func TestInferAuditoryAccessModeSufficient(t *testing.T) {
 	testManifest := func(contains bool, m manifest.Manifest) {
 		res := inferA11yMetadataFromManifest(m)
+		if res == nil && !contains {
+			return
+		}
 		assert.NotNil(t, res)
 		ams := []manifest.A11yPrimaryAccessMode{manifest.A11yPrimaryAccessModeAuditory}
 
@@ -187,6 +223,9 @@ func TestInferAuditoryAccessModeSufficient(t *testing.T) {
 func TestInferVisualAccessModeSufficient(t *testing.T) {
 	testManifest := func(contains bool, m manifest.Manifest) {
 		res := inferA11yMetadataFromManifest(m)
+		if res == nil && !contains {
+			return
+		}
 		assert.NotNil(t, res)
 		ams := []manifest.A11yPrimaryAccessMode{manifest.A11yPrimaryAccessModeVisual}
 
@@ -330,3 +369,9 @@ func assertFeature(t *testing.T, m manifest.Manifest, feature manifest.A11yFeatu
 	assert.NotNil(t, res)
 	assert.Contains(t, res.Features, feature)
 }
+
+func newEPUBPresentation(layout manifest.EPUBLayout) *manifest.Presentation {
+	pres := manifest.NewPresentation()
+	pres.Layout = &layout
+	return pres
+}