Persist language choice across sections (#3633)

Author: zenoachtig

.changeset/red-phones-cough.md

@@ -0,0 +1,5 @@
+---
+"gitbook": patch
+---
+
+Persist language choice across sections if possible

packages/gitbook/src/components/SiteSections/encodeClientSiteSections.ts

@@ -30,9 +30,7 @@ export function encodeClientSiteSections(context: GitBookSiteContext, sections:
  for (const item of list) {
  switch (item.object) {
  case 'site-section-group': {
- const sections = item.sections
- .filter((section) => shouldIncludeSection(context, section))
- .map((section) => encodeSection(context, section));
+ const sections = item.sections.map((section) => encodeSection(context, section));
 
  // Skip empty groups
  if (sections.length === 0) {
@@ -74,38 +72,13 @@ function encodeSection(context: GitBookSiteContext, section: SiteSection) {
  };
 }
 
-/**
- * Test if a section should be included in the list of sections.
- */
-function shouldIncludeSection(context: GitBookSiteContext, section: SiteSection) {
- if (context.site.id !== 'site_JOVzv') {
- return true;
- }
-
- // Testing for a new mode of navigation where the multi-variants section are hidden
- // if they do not include an equivalent of the current site space.
-
- // TODO: replace with a proper flag on the section
- const withNavigateOnlyIfEquivalent = section.id === 'sitesc_4jvEm';
-
- if (!withNavigateOnlyIfEquivalent) {
- return true;
- }
-
- const { siteSpace: currentSiteSpace } = context;
- if (section.siteSpaces.length === 1) {
- return true;
- }
- return section.siteSpaces.some((siteSpace) =>
- areSiteSpacesEquivalent(siteSpace, currentSiteSpace)
- );
-}
-
 /**
  * Find the best default site space to navigate to for a givent section:
  * 1. If we are on the default, continue on the default.
- * 2. If a site space has the same path as the current one, return it.
- * 3. Otherwise, return the default one.
+ * 2. If there are site spaces with the same language as the current, filter by language.
+ * 3. If a site space has the same path as the current one, return it.
+ * 4. Otherwise, return the default first language match.
+ * 5. Otherwise, return the default one.
  */
 function findBestTargetURL(context: GitBookSiteContext, section: SiteSection) {
  const { siteSpace: currentSiteSpace } = context;
@@ -114,9 +87,15 @@ function findBestTargetURL(context: GitBookSiteContext, section: SiteSection) {
  return getSectionURL(context, section);
  }
 
- const bestMatch = section.siteSpaces.find((siteSpace) =>
- areSiteSpacesEquivalent(siteSpace, currentSiteSpace)
- );
+ const possibleMatches =
+ section.siteSpaces.filter((siteSpace) =>
+ areSiteSpacesSameLanguage(siteSpace, currentSiteSpace)
+ ) ?? section.siteSpaces;
+
+ const bestMatch =
+ possibleMatches.find((siteSpace) => areSiteSpacesEquivalent(siteSpace, currentSiteSpace)) ??
+ possibleMatches[0];
+
  if (bestMatch) {
  return getSiteSpaceURL(context, bestMatch);
  }
@@ -130,3 +109,7 @@ function findBestTargetURL(context: GitBookSiteContext, section: SiteSection) {
 function areSiteSpacesEquivalent(siteSpace1: SiteSpace, siteSpace2: SiteSpace) {
  return siteSpace1.path === siteSpace2.path;
 }
+
+function areSiteSpacesSameLanguage(siteSpace1: SiteSpace, siteSpace2: SiteSpace) {
+ return siteSpace1.space.language === siteSpace2.space.language;
+}