Introduce PostListFilter for metadata collection API

Replace PostListParams with PostListFilter in the metadata collection API.
PostListFilter exposes only filter-relevant fields, excluding pagination,
instance-specific (include/exclude), and date range fields that are
incompatible with the metadata sync model.

Changes:
- Add PostListFilter type with documented field exclusions
- Rename post_list_params_cache_key to post_list_filter_cache_key
- Update create_post_metadata_collection_with_edit_context to use PostListFilter
- Update Kotlin extensions and example app ViewModel

Author: oguzkocer

native/kotlin/api/kotlin/src/main/kotlin/rs/wordpress/cache/kotlin/PostServiceExtensions.kt

@@ -1,9 +1,9 @@
 package rs.wordpress.cache.kotlin
 
 import uniffi.wp_api.PostEndpointType
-import uniffi.wp_api.PostListParams
 import uniffi.wp_mobile.AnyPostFilter
 import uniffi.wp_mobile.FullEntityAnyPostWithEditContext
+import uniffi.wp_mobile.PostListFilter
 import uniffi.wp_mobile.PostService
 import uniffi.wp_mobile_cache.EntityId
 
@@ -51,13 +51,13 @@ fun PostService.getObservablePostCollectionWithEditContext(
  * can show appropriate feedback for each item.
  *
  * @param endpointType The post endpoint type (Posts, Pages, or Custom)
- * @param params Post list API parameters (status, author, categories, etc.)
+ * @param filter Filter parameters (status, author, categories, etc.)
  * @return Observable metadata collection that notifies on database changes
  */
 fun PostService.getObservablePostMetadataCollectionWithEditContext(
     endpointType: PostEndpointType,
-    params: PostListParams
+    filter: PostListFilter
 ): ObservableMetadataCollection {
-    val collection = this.createPostMetadataCollectionWithEditContext(endpointType, params)
+    val collection = this.createPostMetadataCollectionWithEditContext(endpointType, filter)
     return createObservableMetadataCollection(collection)
 }

native/kotlin/example/composeApp/src/commonMain/kotlin/rs/wordpress/example/shared/ui/postmetadatacollection/PostMetadataCollectionViewModel.kt

@@ -13,9 +13,9 @@ import rs.wordpress.cache.kotlin.getObservablePostMetadataCollectionWithEditCont
 import rs.wordpress.cache.kotlin.hasMorePages
 import rs.wordpress.cache.kotlin.isSyncing
 import uniffi.wp_api.PostEndpointType
-import uniffi.wp_api.PostListParams
 import uniffi.wp_mobile.ListInfo
 import uniffi.wp_mobile.PostItemState
+import uniffi.wp_mobile.PostListFilter
 import uniffi.wp_mobile.PostMetadataCollectionItem
 import uniffi.wp_mobile.SyncResult
 import uniffi.wp_mobile.WpSelfHostedService
@@ -25,7 +25,7 @@ import uniffi.wp_mobile_cache.ListState
  * UI state for the post metadata collection screen
  */
 data class PostMetadataCollectionState(
-    val currentParams: PostListParams,
+    val currentFilter: PostListFilter,
     val listInfo: ListInfo? = null,
     val lastSyncResult: SyncResult? = null,
     val lastError: String? = null
@@ -51,7 +51,7 @@ data class PostMetadataCollectionState(
 
     val filterDisplayName: String
         get() {
-            val statuses = currentParams.status
+            val statuses = currentFilter.status
             return when {
                 statuses.isEmpty() -> "All Posts"
                 statuses.any { it.toString().contains("draft", ignoreCase = true) } -> "Drafts"
@@ -61,7 +61,7 @@ data class PostMetadataCollectionState(
         }
 
     val filterStatusString: String?
-        get() = currentParams.status.firstOrNull()?.toString()?.lowercase()
+        get() = currentFilter.status.firstOrNull()?.toString()?.lowercase()
 }
 
 /**
@@ -114,7 +114,7 @@ class PostMetadataCollectionViewModel(
 ) {
     private val viewModelScope = CoroutineScope(SupervisorJob() + Dispatchers.Default)
 
-    private val _state = MutableStateFlow(PostMetadataCollectionState(currentParams = PostListParams()))
+    private val _state = MutableStateFlow(PostMetadataCollectionState(currentFilter = PostListFilter()))
     val state: StateFlow<PostMetadataCollectionState> = _state.asStateFlow()
 
     private val _items = MutableStateFlow<List<PostItemDisplayData>>(emptyList())
@@ -123,7 +123,7 @@ class PostMetadataCollectionViewModel(
     private var observableCollection: ObservableMetadataCollection? = null
 
     init {
-        createObservableCollection(_state.value.currentParams)
+        createObservableCollection(_state.value.currentFilter)
         loadItemsFromCollection()
     }
 
@@ -132,16 +132,16 @@ class PostMetadataCollectionViewModel(
      */
     fun setFilter(status: String?) {
         val postStatus = status?.let { uniffi.wp_api.parsePostStatus(it) }
-        val newParams = PostListParams(
+        val newFilter = PostListFilter(
             status = if (postStatus != null) listOf(postStatus) else emptyList()
         )
 
         observableCollection?.close()
-        createObservableCollection(newParams)
+        createObservableCollection(newFilter)
 
         // Read persisted state from database (single query)
         _state.value = PostMetadataCollectionState(
-            currentParams = newParams,
+            currentFilter = newFilter,
             listInfo = observableCollection?.listInfo(),
             lastSyncResult = null,
             lastError = null
@@ -216,11 +216,11 @@ class PostMetadataCollectionViewModel(
         }
     }
 
-    private fun createObservableCollection(params: PostListParams) {
+    private fun createObservableCollection(filter: PostListFilter) {
         val postService = selfHostedService.posts()
         val observable = postService.getObservablePostMetadataCollectionWithEditContext(
             PostEndpointType.Posts,
-            params
+            filter
         )
 
         // Data observer: refresh list contents when data changes

wp_mobile/src/cache_key.rs

@@ -1,16 +1,18 @@
 //! Cache key generation for metadata collections.
 //!
 //! This module provides functions to generate deterministic cache keys from
-//! API parameters. The cache key is used to identify unique list configurations
+//! filter parameters. The cache key is used to identify unique list configurations
 //! in the metadata store.
 
 use url::Url;
 use wp_api::{
-    posts::{PostListParams, PostListParamsField},
+    posts::PostListParamsField,
     request::endpoint::posts_endpoint::PostEndpointType,
     url_query::AsQueryValue,
 };
 
+use crate::filters::PostListFilter;
+
 /// Generates a cache key segment from a `PostEndpointType`.
 ///
 /// Uses a `post_type_` prefix to avoid conflicts with custom post type names
@@ -66,137 +68,76 @@ impl QueryPairsExt for url::form_urlencoded::Serializer<'_, url::UrlQuery<'_>> {
     }
 }
 
-/// Generates a deterministic cache key from `PostListParams`.
+/// Generates a deterministic cache key from `PostListFilter`.
 ///
-/// This function explicitly includes only filter-relevant fields, excluding
-/// pagination and instance-specific fields. Each excluded field has a comment
-/// explaining why it's not part of the cache key.
+/// All fields in `PostListFilter` are included in the cache key since it only
+/// contains filter-relevant fields (pagination, instance-specific, and date
+/// range fields are excluded by design in `PostListFilter`).
 ///
 /// # Arguments
-/// * `params` - The post list parameters to generate a cache key from
+/// * `filter` - The post list filter to generate a cache key from
 ///
 /// # Returns
-/// A URL query string containing only the filter-relevant parameters,
+/// A URL query string containing the filter parameters in alphabetical order,
 /// suitable for use as a cache key suffix.
 ///
 /// # Example
 /// ```ignore
-/// let params = PostListParams {
+/// let filter = PostListFilter {
 ///     status: vec![PostStatus::Publish],
 ///     author: vec![UserId(5)],
 ///     ..Default::default()
 /// };
-/// let key = post_list_params_cache_key(&params);
+/// let key = post_list_filter_cache_key(&filter);
 /// // key = "author=5&status=publish"
 /// ```
-pub fn post_list_params_cache_key(params: &PostListParams) -> String {
+pub fn post_list_filter_cache_key(filter: &PostListFilter) -> String {
     let mut url = Url::parse("https://cache-key-generator.local").expect("valid base URL");
 
     {
         let mut q = url.query_pairs_mut();
 
-        // ============================================================
-        // EXCLUDED FIELDS (not part of cache key)
-        // ============================================================
-
-        // `page` - Excluded: pagination is managed by the collection, not the filter
-        // `per_page` - Excluded: pagination is managed by the collection, not the filter
-        // `offset` - Excluded: pagination is managed by the collection, not the filter
-        // `include` - Excluded: instance-specific, used for fetching specific posts by ID
-        // `exclude` - Excluded: instance-specific, used for excluding specific posts by ID
-
-        // ============================================================
-        // INCLUDED FIELDS (alphabetically ordered for determinism)
-        // ============================================================
-
-        // after - Filter: limit to posts published after this date
-        q.append_option(PostListParamsField::After.into(), params.after.as_ref());
-
-        // author - Filter: limit to posts by specific authors
-        q.append_vec(PostListParamsField::Author.into(), &params.author);
+        // All fields in PostListFilter are included (alphabetically ordered for determinism).
+        // Fields excluded from PostListFilter (pagination, instance-specific, date ranges)
+        // are documented in the PostListFilter type definition.
 
-        // author_exclude - Filter: exclude posts by specific authors
+        q.append_vec(PostListParamsField::Author.into(), &filter.author);
         q.append_vec(
             PostListParamsField::AuthorExclude.into(),
-            &params.author_exclude,
+            &filter.author_exclude,
         );
-
-        // before - Filter: limit to posts published before this date
-        q.append_option(PostListParamsField::Before.into(), params.before.as_ref());
-
-        // categories - Filter: limit to posts in specific categories
-        q.append_vec(PostListParamsField::Categories.into(), &params.categories);
-
-        // categories_exclude - Filter: exclude posts in specific categories
+        q.append_vec(PostListParamsField::Categories.into(), &filter.categories);
         q.append_vec(
             PostListParamsField::CategoriesExclude.into(),
-            &params.categories_exclude,
+            &filter.categories_exclude,
         );
-
-        // menu_order - Filter: limit by menu order (for hierarchical post types)
         q.append_option(
             PostListParamsField::MenuOrder.into(),
-            params.menu_order.as_ref(),
-        );
-
-        // modified_after - Filter: limit to posts modified after this date
-        q.append_option(
-            PostListParamsField::ModifiedAfter.into(),
-            params.modified_after.as_ref(),
-        );
-
-        // modified_before - Filter: limit to posts modified before this date
-        q.append_option(
-            PostListParamsField::ModifiedBefore.into(),
-            params.modified_before.as_ref(),
+            filter.menu_order.as_ref(),
         );
-
-        // order - Ordering: affects which posts appear on each page
-        q.append_option(PostListParamsField::Order.into(), params.order.as_ref());
-
-        // orderby - Ordering: affects which posts appear on each page
-        q.append_option(PostListParamsField::Orderby.into(), params.orderby.as_ref());
-
-        // parent - Filter: limit to posts with specific parent (hierarchical)
-        q.append_option(PostListParamsField::Parent.into(), params.parent.as_ref());
-
-        // parent_exclude - Filter: exclude posts with specific parents
+        q.append_option(PostListParamsField::Order.into(), filter.order.as_ref());
+        q.append_option(PostListParamsField::Orderby.into(), filter.orderby.as_ref());
+        q.append_option(PostListParamsField::Parent.into(), filter.parent.as_ref());
         q.append_vec(
             PostListParamsField::ParentExclude.into(),
-            &params.parent_exclude,
+            &filter.parent_exclude,
         );
-
-        // search - Filter: limit to posts matching search string
-        q.append_option(PostListParamsField::Search.into(), params.search.as_ref());
-
-        // search_columns - Filter: which columns to search in
+        q.append_option(PostListParamsField::Search.into(), filter.search.as_ref());
         q.append_vec(
             PostListParamsField::SearchColumns.into(),
-            &params.search_columns,
+            &filter.search_columns,
         );
-
-        // slug - Filter: limit to posts with specific slugs
-        q.append_vec(PostListParamsField::Slug.into(), &params.slug);
-
-        // status - Filter: limit to posts with specific statuses
-        q.append_vec(PostListParamsField::Status.into(), &params.status);
-
-        // sticky - Filter: limit to sticky or non-sticky posts
-        q.append_option(PostListParamsField::Sticky.into(), params.sticky.as_ref());
-
-        // tags - Filter: limit to posts with specific tags
-        q.append_vec(PostListParamsField::Tags.into(), &params.tags);
-
-        // tags_exclude - Filter: exclude posts with specific tags
+        q.append_vec(PostListParamsField::Slug.into(), &filter.slug);
+        q.append_vec(PostListParamsField::Status.into(), &filter.status);
+        q.append_option(PostListParamsField::Sticky.into(), filter.sticky.as_ref());
+        q.append_vec(PostListParamsField::Tags.into(), &filter.tags);
         q.append_vec(
             PostListParamsField::TagsExclude.into(),
-            &params.tags_exclude,
+            &filter.tags_exclude,
         );
-
-        // tax_relation - Filter: relationship between taxonomy filters (AND/OR)
         q.append_option(
             PostListParamsField::TaxRelation.into(),
-            params.tax_relation.as_ref(),
+            filter.tax_relation.as_ref(),
         );
     }
 
@@ -209,72 +150,43 @@ mod tests {
     use wp_api::posts::PostStatus;
 
     #[test]
-    fn test_empty_params_produces_empty_key() {
-        let params = PostListParams::default();
-        let key = post_list_params_cache_key(&params);
+    fn test_empty_filter_produces_empty_key() {
+        let filter = PostListFilter::default();
+        let key = post_list_filter_cache_key(&filter);
         assert_eq!(key, "");
     }
 
     #[test]
     fn test_status_filter() {
-        let params = PostListParams {
+        let filter = PostListFilter {
             status: vec![PostStatus::Publish],
             ..Default::default()
         };
-        let key = post_list_params_cache_key(&params);
+        let key = post_list_filter_cache_key(&filter);
         assert_eq!(key, "status=publish");
     }
 
     #[test]
     fn test_multiple_statuses() {
-        let params = PostListParams {
+        let filter = PostListFilter {
             status: vec![PostStatus::Publish, PostStatus::Draft],
             ..Default::default()
         };
-        let key = post_list_params_cache_key(&params);
+        let key = post_list_filter_cache_key(&filter);
         assert_eq!(key, "status=publish%2Cdraft");
     }
 
-    #[test]
-    fn test_pagination_fields_excluded() {
-        let params = PostListParams {
-            page: Some(5),
-            per_page: Some(20),
-            offset: Some(100),
-            status: vec![PostStatus::Publish],
-            ..Default::default()
-        };
-        let key = post_list_params_cache_key(&params);
-        // Should only contain status, not page/per_page/offset
-        assert_eq!(key, "status=publish");
-    }
-
-    #[test]
-    fn test_include_exclude_fields_excluded() {
-        use wp_api::posts::PostId;
-
-        let params = PostListParams {
-            include: vec![PostId(1), PostId(2)],
-            exclude: vec![PostId(3), PostId(4)],
-            status: vec![PostStatus::Draft],
-            ..Default::default()
-        };
-        let key = post_list_params_cache_key(&params);
-        // Should only contain status, not include/exclude
-        assert_eq!(key, "status=draft");
-    }
-
     #[test]
     fn test_multiple_filters_alphabetically_ordered() {
         use wp_api::users::UserId;
 
-        let params = PostListParams {
+        let filter = PostListFilter {
             status: vec![PostStatus::Publish],
             author: vec![UserId(5)],
             search: Some("hello".to_string()),
             ..Default::default()
         };
-        let key = post_list_params_cache_key(&params);
+        let key = post_list_filter_cache_key(&filter);
         // Fields should be in alphabetical order: author, search, status
         assert_eq!(key, "author=5&search=hello&status=publish");
     }