Fixes fetching terms on XML-RPC disabled sites (#25767)

* Route tags and categories to the REST API on self-hosted sites

Self-hosted taxonomy went through XML-RPC term methods, which some hosts block at the WAF, breaking tags and categories on new posts (#25758). Prefer the core REST API (wp/v2) whenever the site has application-password access, keeping XML-RPC only as a fallback for legacy sites without it.

* Replace TagsViewModel convenience inits with named factory methods

The two convenience initializers were ambiguous about when to use each. Introduce tags(for:) and taxonomy(_:client:) so call sites read by intent, and drop the unused blog parameter that was threaded through the custom taxonomy path.

* Add release note

* Format taxonomy Core REST service

* Use view context for taxonomy reads

* Fix a swiftlint issue

Author: crazytonyli

RELEASE-NOTES.txt

@@ -4,6 +4,7 @@
 * [*] [internal] In-app updates: guard the flexible update notice against double-posting when two update checks race [#25666]
 * [*] [build tooling] Add a String Catalog localization pipeline (plurals + build-free catalog generation) with a CI coverage gate [#25688]
 * [*] [internal] Stats widgets: migrate the site picker from SiriKit to App Intents [#25753]
+* [*] Fix categories and tags not working on self-hosted sites with XML-RPC disabled [#25767]
 * [*] Fix Blogging Reminders text color in dark mode [#25780]
 * [*] Share extensions: Fix the site picker showing an error while sites are still loading [#25798]
 * [*] Share Extension: Fix a crash after uploading a post to WordPress.com [#25773]

WordPress/Classes/Services/PostCategoryService.m

@@ -184,8 +184,16 @@ - (void)mergeCategories:(NSArray <RemotePostCategory *> *)remoteCategories forBl
         if (blog.wordPressComRestApi) {
             return [[TaxonomyServiceRemoteREST alloc] initWithWordPressComRestApi:blog.wordPressComRestApi siteID:blog.dotComID];
         }
-    } else if (blog.xmlrpcApi) {
-        return [[TaxonomyServiceRemoteXMLRPC alloc] initWithApi:blog.xmlrpcApi username:blog.username password:blog.password];
+    } else {
+        // Prefer the core REST API (wp/v2) for self-hosted sites. Some hosts
+        // block the XML-RPC term methods, which breaks categories (#25758).
+        TaxonomyServiceRemoteCoreREST *coreREST = [[TaxonomyServiceRemoteCoreREST alloc] initWithBlog:blog];
+        if (coreREST) {
+            return coreREST;
+        }
+        if (blog.xmlrpcApi) {
+            return [[TaxonomyServiceRemoteXMLRPC alloc] initWithApi:blog.xmlrpcApi username:blog.username password:blog.password];
+        }
     }
     return nil;
 }

WordPress/Classes/Services/TaxonomyServiceRemoteCoreREST.swift

@@ -17,7 +17,11 @@ import WordPressAPI
         self.client = client
     }
 
-    public func createCategory(_ category: RemotePostCategory, success: ((RemotePostCategory) -> Void)?, failure: ((any Error) -> Void)? = nil) {
+    public func createCategory(
+        _ category: RemotePostCategory,
+        success: ((RemotePostCategory) -> Void)?,
+        failure: ((any Error) -> Void)? = nil
+    ) {
         Task { @MainActor in
             do {
                 let params = TermCreateParams(
@@ -33,10 +37,13 @@ import WordPressAPI
         }
     }
 
-    public func getCategoriesWithSuccess(_ success: @escaping ([RemotePostCategory]) -> Void, failure: ((any Error) -> Void)? = nil) {
+    public func getCategoriesWithSuccess(
+        _ success: @escaping ([RemotePostCategory]) -> Void,
+        failure: ((any Error) -> Void)? = nil
+    ) {
         Task { @MainActor in
             do {
-                let sequence = await client.api.terms.sequenceWithEditContext(
+                let sequence = await client.api.terms.sequenceWithViewContext(
                     type: .categories,
                     params: TermListParams(perPage: 100)
                 )
@@ -51,7 +58,11 @@ import WordPressAPI
         }
     }
 
-    public func getCategoriesWith(_ paging: RemoteTaxonomyPaging, success: @escaping ([RemotePostCategory]) -> Void, failure: ((any Error) -> Void)? = nil) {
+    public func getCategoriesWith(
+        _ paging: RemoteTaxonomyPaging,
+        success: @escaping ([RemotePostCategory]) -> Void,
+        failure: ((any Error) -> Void)? = nil
+    ) {
         Task { @MainActor in
             do {
                 let params = TermListParams(
@@ -61,7 +72,7 @@ import WordPressAPI
                     order: WpApiParamOrder(paging.order),
                     orderby: WpApiParamTermsOrderBy(paging.orderBy)
                 )
-                let response = try await client.api.terms.listWithEditContext(
+                let response = try await client.api.terms.listWithViewContext(
                     termEndpointType: .categories,
                     params: params
                 )
@@ -73,11 +84,15 @@ import WordPressAPI
         }
     }
 
-    public func searchCategories(withName nameQuery: String, success: @escaping ([RemotePostCategory]) -> Void, failure: ((any Error) -> Void)? = nil) {
+    public func searchCategories(
+        withName nameQuery: String,
+        success: @escaping ([RemotePostCategory]) -> Void,
+        failure: ((any Error) -> Void)? = nil
+    ) {
         Task { @MainActor in
             do {
                 let params = TermListParams(search: nameQuery)
-                let response = try await client.api.terms.listWithEditContext(
+                let response = try await client.api.terms.listWithViewContext(
                     termEndpointType: .categories,
                     params: params
                 )
@@ -89,7 +104,11 @@ import WordPressAPI
         }
     }
 
-    public func createTag(_ tag: RemotePostTag, success: ((RemotePostTag) -> Void)?, failure: ((any Error) -> Void)? = nil) {
+    public func createTag(
+        _ tag: RemotePostTag,
+        success: ((RemotePostTag) -> Void)?,
+        failure: ((any Error) -> Void)? = nil
+    ) {
         Task { @MainActor in
             do {
                 let params = TermCreateParams(
@@ -109,7 +128,11 @@ import WordPressAPI
         }
     }
 
-    public func update(_ tag: RemotePostTag, success: ((RemotePostTag) -> Void)?, failure: ((any Error) -> Void)? = nil) {
+    public func update(
+        _ tag: RemotePostTag,
+        success: ((RemotePostTag) -> Void)?,
+        failure: ((any Error) -> Void)? = nil
+    ) {
         guard let tagID = tag.tagID else {
             failure?(URLError(.unknown))
             return
@@ -151,10 +174,13 @@ import WordPressAPI
         }
     }
 
-    public func getTagsWithSuccess(_ success: @escaping ([RemotePostTag]) -> Void, failure: ((any Error) -> Void)? = nil) {
+    public func getTagsWithSuccess(
+        _ success: @escaping ([RemotePostTag]) -> Void,
+        failure: ((any Error) -> Void)? = nil
+    ) {
         Task { @MainActor in
             do {
-                let response = try await client.api.terms.listWithEditContext(
+                let response = try await client.api.terms.listWithViewContext(
                     termEndpointType: .tags,
                     params: TermListParams()
                 )
@@ -166,7 +192,11 @@ import WordPressAPI
         }
     }
 
-    public func getTagsWith(_ paging: RemoteTaxonomyPaging, success: @escaping ([RemotePostTag]) -> Void, failure: ((any Error) -> Void)? = nil) {
+    public func getTagsWith(
+        _ paging: RemoteTaxonomyPaging,
+        success: @escaping ([RemotePostTag]) -> Void,
+        failure: ((any Error) -> Void)? = nil
+    ) {
         Task { @MainActor in
             do {
                 let params = TermListParams(
@@ -176,7 +206,7 @@ import WordPressAPI
                     order: WpApiParamOrder(paging.order),
                     orderby: WpApiParamTermsOrderBy(paging.orderBy)
                 )
-                let response = try await client.api.terms.listWithEditContext(
+                let response = try await client.api.terms.listWithViewContext(
                     termEndpointType: .tags,
                     params: params
                 )
@@ -188,10 +218,14 @@ import WordPressAPI
         }
     }
 
-    public func searchTags(withName nameQuery: String, success: @escaping ([RemotePostTag]) -> Void, failure: ((any Error) -> Void)? = nil) {
+    public func searchTags(
+        withName nameQuery: String,
+        success: @escaping ([RemotePostTag]) -> Void,
+        failure: ((any Error) -> Void)? = nil
+    ) {
         Task { @MainActor in
             do {
-                let response = try await client.api.terms.listWithEditContext(
+                let response = try await client.api.terms.listWithViewContext(
                     termEndpointType: .tags,
                     params: TermListParams(search: nameQuery)
                 )
@@ -205,6 +239,13 @@ import WordPressAPI
 }
 
 private extension RemotePostCategory {
+    convenience init(category: AnyTermWithViewContext) {
+        self.init()
+        self.categoryID = NSNumber(value: category.id)
+        self.name = category.name
+        self.parentID = NSNumber(value: category.parent ?? 0)
+    }
+
     convenience init(category: AnyTermWithEditContext) {
         self.init()
         self.categoryID = NSNumber(value: category.id)
@@ -214,6 +255,15 @@ private extension RemotePostCategory {
 }
 
 private extension RemotePostTag {
+    convenience init(tag: AnyTermWithViewContext) {
+        self.init()
+        self.tagID = NSNumber(value: tag.id)
+        self.name = tag.name
+        self.slug = tag.slug
+        self.tagDescription = tag.description
+        self.postCount = NSNumber(value: tag.count)
+    }
+
     convenience init(tag: AnyTermWithEditContext) {
         self.init()
         self.tagID = NSNumber(value: tag.id)

WordPress/Classes/ViewRelated/Blog/Site Settings/SiteSettingsViewController+Swift.swift

@@ -62,7 +62,7 @@ extension SiteSettingsViewController {
     @objc public func showCustomTaxonomies() {
         let viewController: UIViewController
         if let client = try? WordPressClientFactory.shared.instance(for: .init(blog: blog)) {
-            let rootView = SiteCustomTaxonomiesView(blog: self.blog, client: client)
+            let rootView = SiteCustomTaxonomiesView(client: client)
             viewController = UIHostingController(rootView: rootView)
         } else {
             let feature = NSLocalizedString(
@@ -76,7 +76,7 @@ extension SiteSettingsViewController {
                 source: "taxonomies",
                 presentingViewController: self
             ) { client in
-                SiteCustomTaxonomiesView(blog: self.blog, client: client)
+                SiteCustomTaxonomiesView(client: client)
             }
             viewController = UIHostingController(rootView: rootView)
         }

WordPress/Classes/ViewRelated/Post/PostSettings/PostSettingsView.swift

@@ -243,7 +243,6 @@ struct PostSettingsFormContentView<ViewModel: PostSettingsViewModelProtocol>: Vi
             ForEach(viewModel.customTaxonomies, id: \.slug) { taxonomy in
                 NavigationLink {
                     PostTagsView(
-                        blog: viewModel.blog,
                         client: client,
                         taxonomy: taxonomy,
                         selectedTerms: viewModel.settings.getTerms(forTaxonomySlug: taxonomy.slug)

WordPress/Classes/ViewRelated/Post/PostSettings/PostSettingsViewModel.swift

@@ -302,7 +302,7 @@ final class PostSettingsViewModel: NSObject, ObservableObject, PostSettingsViewM
         Task { [weak self] in
             guard let self else { return }
 
-            let service = TagsService(blog: blog)
+            let service = TagsViewModel.makeTagsService(for: blog)
             let resolved = await service.resolveTerms(named: pendingNames)
             for (name, existing) in resolved {
                 if let index = settings.tags.firstIndex(where: { $0.name == name }) {

WordPress/Classes/ViewRelated/Post/PostSettings/Views/PostTagsView.swift

@@ -12,14 +12,14 @@ struct PostTagsView: View {
     @State private var isKeyboardPresented = false
 
     init(blog: Blog, selectedTags: [TagsViewModel.SelectedTerm], onSelectionChanged: @escaping ([TagsViewModel.SelectedTerm]) -> Void) {
-        let viewModel = TagsViewModel(blog: blog, selectedTags: selectedTags, mode: .selection(onSelectedTagsChanged: { tags in
+        let viewModel = TagsViewModel.tags(for: blog, selectedTerms: selectedTags, mode: .selection(onSelectedTagsChanged: { tags in
             onSelectionChanged(tags)
         }))
         self._viewModel = StateObject(wrappedValue: viewModel)
     }
 
-    init(blog: Blog, client: WordPressClient, taxonomy: SiteTaxonomy, selectedTerms: [TagsViewModel.SelectedTerm] = [], onSelectionChanged: @escaping ([TagsViewModel.SelectedTerm]) -> Void) {
-        let viewModel = TagsViewModel(blog: blog, client: client, taxonomy: taxonomy, selectedTerms: selectedTerms, mode: .selection(onSelectedTagsChanged: { tags in
+    init(client: WordPressClient, taxonomy: SiteTaxonomy, selectedTerms: [TagsViewModel.SelectedTerm] = [], onSelectionChanged: @escaping ([TagsViewModel.SelectedTerm]) -> Void) {
+        let viewModel = TagsViewModel.taxonomy(taxonomy, client: client, selectedTerms: selectedTerms, mode: .selection(onSelectedTagsChanged: { tags in
             onSelectionChanged(tags)
         }))
         self._viewModel = StateObject(wrappedValue: viewModel)

WordPress/Classes/ViewRelated/Tags/SiteCustomTaxonomiesView.swift

@@ -7,23 +7,21 @@ import WordPressShared
 import WordPressUI
 
 struct SiteCustomTaxonomiesView: View {
-    let blog: Blog
     let client: WordPressClient
 
     @State private var isLoading: Bool = false
     @State private var taxonomies: [SiteTaxonomy]? = nil
     @State private var error: Error?
 
-    init(blog: Blog, client: WordPressClient) {
-        self.blog = blog
+    init(client: WordPressClient) {
         self.client = client
     }
 
     var body: some View {
         List {
             ForEach(taxonomies ?? [], id: \.slug) { taxonomy in
                 NavigationLink {
-                    SiteTagsView(viewModel: .init(blog: blog, client: client, taxonomy: taxonomy, mode: .browse))
+                    SiteTagsView(viewModel: .taxonomy(taxonomy, client: client, mode: .browse))
                 } label: {
                     Text(taxonomy.localizedName)
                 }

WordPress/Classes/ViewRelated/Tags/SiteTagsView.swift

@@ -193,7 +193,7 @@ class SiteTagsViewController: UIHostingController<SiteTagsView> {
     let viewModel: TagsViewModel
 
     init(blog: Blog) {
-        viewModel = TagsViewModel(blog: blog, mode: .browse)
+        viewModel = TagsViewModel.tags(for: blog, mode: .browse)
         super.init(rootView: .init(viewModel: viewModel))
     }
 

WordPress/Classes/ViewRelated/Tags/TagsViewModel.swift

@@ -57,25 +57,41 @@ class TagsViewModel: ObservableObject {
         return false
     }
 
-    convenience init(blog: Blog, selectedTags: [SelectedTerm] = [], mode: TagsViewMode) {
-        self.init(taxonomy: nil, service: TagsService(blog: blog), selectedTerms: selectedTags, mode: mode)
+    /// Builds a view model for a site's built-in tags. `makeTagsService(for:)`
+    /// picks the backing service so self-hosted sites use REST where they can
+    /// (issue #25758).
+    static func tags(
+        for blog: Blog,
+        selectedTerms: [SelectedTerm] = [],
+        mode: TagsViewMode
+    ) -> TagsViewModel {
+        TagsViewModel(
+            taxonomy: nil,
+            service: makeTagsService(for: blog),
+            selectedTerms: selectedTerms,
+            mode: mode
+        )
     }
 
-    convenience init(
-        blog: Blog,
+    /// Builds a view model for a specific site `taxonomy` (e.g. a custom
+    /// taxonomy). Always uses the core REST API, which a custom taxonomy's
+    /// `client` already guarantees is available.
+    static func taxonomy(
+        _ taxonomy: SiteTaxonomy,
         client: WordPressClient,
-        taxonomy: SiteTaxonomy,
         selectedTerms: [SelectedTerm] = [],
         mode: TagsViewMode
-    ) {
-        self.init(
+    ) -> TagsViewModel {
+        TagsViewModel(
             taxonomy: taxonomy,
             service: AnyTermService(client: client, endpoint: taxonomy.endpoint),
             selectedTerms: selectedTerms,
             mode: mode
         )
     }
 
+    /// Designated initializer. Inject a `service` directly; production code
+    /// should prefer the `tags(for:)` / `taxonomy(_:client:)` factories.
     init(
         taxonomy: SiteTaxonomy?,
         service: TaxonomyServiceProtocol,
@@ -90,6 +106,24 @@ class TagsViewModel: ObservableObject {
         self.selectedTagsSet = Set(selectedTerms.map { $0.name.lowercased() })
     }
 
+    /// Chooses the taxonomy service backing a blog's tags.
+    ///
+    /// Sites with core REST API access (WordPress.com, or self-hosted sites with
+    /// an application password) use `AnyTermService` so tags go through the wp/v2
+    /// REST API. Some hosts block the XML-RPC term methods that `TagsService`
+    /// uses for self-hosted sites, which breaks tags entirely (issue #25758).
+    /// Legacy self-hosted sites without REST access keep using `TagsService`.
+    static func makeTagsService(
+        for blog: Blog,
+        keychain: KeychainAccessible = AppKeychain()
+    ) -> TaxonomyServiceProtocol {
+        if let site = try? WordPressSite(blog: blog, keychain: keychain) {
+            let client = WordPressClientFactory.shared.instance(for: site)
+            return AnyTermService(client: client, endpoint: .tags)
+        }
+        return TagsService(blog: blog)
+    }
+
     func onAppear() {
         guard response == nil else { return }
         Task {