core: allow to disable all next and prev links from global config

packages/@vuepress/theme-default/components/Page.vue

@@ -62,6 +62,9 @@
 </template>
 
 <script>
+import isString from 'lodash/isString'
+import isNil from 'lodash/isNil'
+
 import { resolvePage, outboundRE, endingSlashRE } from '../util'
 
 export default {
@@ -83,25 +86,11 @@ export default {
     },
 
     prev () {
-      const prev = this.$page.frontmatter.prev
-      if (prev === false) {
-        return
-      } else if (prev) {
-        return resolvePage(this.$site.pages, prev, this.$route.path)
-      } else {
-        return resolvePrev(this.$page, this.sidebarItems)
-      }
+      return resolvePageLink(LINK_TYPES.PREV, this)
     },
 
     next () {
-      const next = this.$page.frontmatter.next
-      if (next === false) {
-        return
-      } else if (next) {
-        return resolvePage(this.$site.pages, next, this.$route.path)
-      } else {
-        return resolveNext(this.$page, this.sidebarItems)
-      }
+      return resolvePageLink(LINK_TYPES.NEXT, this)
     },
 
     editLink () {
@@ -161,6 +150,11 @@ export default {
   }
 }
 
+const LINK_TYPES = {
+  NEXT: 'next',
+  PREV: 'prev'
+}
+
 function resolvePrev (page, items) {
   return find(page, items, -1)
 }
@@ -169,6 +163,29 @@ function resolveNext (page, items) {
   return find(page, items, 1)
 }
 
+function resolvePageLink(linkType, { $themeConfig, $page, $route, $site, sidebarItems }) {
+  const resolveLink = linkType === LINK_TYPES.NEXT ? resolveNext : resolvePrev
+
+  // Get link config from theme
+  const { nextLinks, prevLinks } = $themeConfig
+  const themeLinkConfig = linkType === LINK_TYPES.NEXT ? nextLinks : prevLinks
+
+  // Get link config from current page
+  const { next, prev } = $page.frontmatter
+  const pageLinkConfig = linkType === LINK_TYPES.NEXT ? next : prev
+
+  // Page link config will overwrite global theme link config if defined
+  const link = isNil(pageLinkConfig) ? themeLinkConfig : pageLinkConfig
+
+  if (link === false) {
+    return
+  } else if (isString(link)) {
+    return resolvePage($site.pages, link, $route.path)
+  } else {
+    return resolveLink($page, sidebarItems)
+  }
+}
+
 function find (page, items, offset) {
   const res = []
   flatten(items, res)