Minor pagination issues fixed.

config/processor.go

@@ -71,19 +71,23 @@ func DefaultProcessorConfig() map[string]interface{} {
 			internal.ProcessTxCommitOrRollback,
 		},
 		"get_processes": []string{
+			internal.ProcessCheckPagination,
 			internal.ProcessFillEmptyFieldset,
 			internal.ProcessConvertRelationFiltersSafe,
 			internal.ProcessHookBeforeGet,
+			internal.ProcessCheckPagination,
 			internal.ProcessConvertRelationFiltersSafe,
 			internal.ProcessGet,
 			internal.ProcessGetForeignRelations,
 			internal.ProcessHookAfterGet,
 			internal.ProcessGetIncludedSafe,
 		},
 		"list_processes": []string{
+			internal.ProcessCheckPagination,
 			internal.ProcessFillEmptyFieldset,
 			internal.ProcessConvertRelationFiltersSafe,
 			internal.ProcessHookBeforeList,
+			internal.ProcessCheckPagination,
 			internal.ProcessConvertRelationFiltersSafe,
 			internal.ProcessList,
 			internal.ProcessGetForeignRelationsSafe,
@@ -139,9 +143,11 @@ func ThreadSafeProcessor() *Processor {
 			internal.ProcessGetIncludedSafe,
 		},
 		ListProcesses: ProcessList{
+			internal.ProcessCheckPagination,
 			internal.ProcessFillEmptyFieldset,
 			internal.ProcessConvertRelationFiltersSafe,
 			internal.ProcessHookBeforeList,
+			internal.ProcessCheckPagination,
 			internal.ProcessConvertRelationFiltersSafe,
 			internal.ProcessList,
 			internal.ProcessGetForeignRelationsSafe,
@@ -187,18 +193,22 @@ func ConcurrentProcessor() *Processor {
 			internal.ProcessTxCommitOrRollback,
 		},
 		GetProcesses: ProcessList{
+			internal.ProcessCheckPagination,
 			internal.ProcessFillEmptyFieldset,
 			internal.ProcessConvertRelationFilters,
 			internal.ProcessHookBeforeGet,
+			internal.ProcessCheckPagination,
 			internal.ProcessConvertRelationFilters,
 			internal.ProcessGet,
 			internal.ProcessGetForeignRelations,
 			internal.ProcessHookAfterGet,
 		},
 		ListProcesses: ProcessList{
+			internal.ProcessCheckPagination,
 			internal.ProcessFillEmptyFieldset,
 			internal.ProcessConvertRelationFilters,
 			internal.ProcessHookBeforeList,
+			internal.ProcessCheckPagination,
 			internal.ProcessConvertRelationFilters,
 			internal.ProcessList,
 			internal.ProcessGetForeignRelations,
@@ -244,17 +254,21 @@ func DefaultConcurrentProcessorConfig() map[string]interface{} {
 			internal.ProcessTxCommitOrRollback,
 		},
 		"get_processes": []string{
+			internal.ProcessCheckPagination,
 			internal.ProcessFillEmptyFieldset,
 			internal.ProcessConvertRelationFilters,
 			internal.ProcessHookBeforeGet,
+			internal.ProcessCheckPagination,
 			internal.ProcessConvertRelationFilters,
 			internal.ProcessGet,
 			internal.ProcessGetForeignRelations,
 		},
 		"list_processes": []string{
+			internal.ProcessCheckPagination,
 			internal.ProcessFillEmptyFieldset,
 			internal.ProcessConvertRelationFilters,
 			internal.ProcessHookBeforeList,
+			internal.ProcessCheckPagination,
 			internal.ProcessConvertRelationFilters,
 			internal.ProcessList,
 			internal.ProcessGetForeignRelations,

internal/processes.go

@@ -5,6 +5,7 @@ var Processes = make(map[string]struct{})
 
 // Processes constant names.
 const (
+	// Create processes
 	ProcessHookBeforeCreate          = "hook_before_create"
 	ProcessSetBelongsToRelations     = "set_belongs_to_relations"
 	ProcessCreate                    = "create"
@@ -13,6 +14,7 @@ const (
 	ProcessPatchForeignRelationsSafe = "patch_foreign_relationships_safe"
 	ProcessHookAfterCreate           = "hook_after_create"
 
+	// Get processes
 	ProcessFillEmptyFieldset          = "fill_empty_fieldset"
 	ProcessConvertRelationFilters     = "convert_relation_filters"
 	ProcessConvertRelationFiltersSafe = "convert_relation_filters_safe"
@@ -22,24 +24,29 @@ const (
 	ProcessGetForeignRelationsSafe    = "get_foreign_relations_safe"
 	ProcessHookAfterGet               = "hook_after_get"
 
+	// List processes
+	ProcessCheckPagination = "check_pagination"
 	ProcessHookBeforeList  = "hook_before_list"
 	ProcessList            = "list"
 	ProcessHookAfterList   = "hook_after_list"
 	ProcessGetIncluded     = "get_included"
 	ProcessGetIncludedSafe = "get_included_safe"
 
+	// Patch processes
 	ProcessHookBeforePatch         = "hook_before_patch"
 	ProcessPatch                   = "patch"
 	ProcessHookAfterPatch          = "hook_after_patch"
 	ProcessPatchBelongsToRelations = "patch_belongs_to_relations"
 
+	// Delete processes
 	ProcessReducePrimaryFilters       = "reduce_primary_filters"
 	ProcessHookBeforeDelete           = "hook_before_delete"
 	ProcessDelete                     = "delete"
 	ProcessHookAfterDelete            = "hook_after_delete"
 	ProcessDeleteForeignRelations     = "delete_foreign_relations"
 	ProcessDeleteForeignRelationsSafe = "delete_foreign_relations_safe"
 
+	// Transaction processes
 	ProcessTxBegin            = "tx_begin"
 	ProcessTxCommitOrRollback = "tx_commit_or_rollback"
 )

query/const.go

@@ -56,6 +56,7 @@ const (
 	ProcessGetForeignRelationsSafe    = internal.ProcessGetForeignRelationsSafe
 	ProcessHookAfterGet               = internal.ProcessHookAfterGet
 
+	ProcessCheckPagination = internal.ProcessCheckPagination
 	ProcessHookBeforeList  = internal.ProcessHookBeforeList
 	ProcessList            = internal.ProcessList
 	ProcessHookAfterList   = internal.ProcessHookAfterList

query/pagination.go

@@ -49,6 +49,10 @@ const (
 // Pagination defines the query limits and offsets.
 // It defines the maximum size (Limit) as well as an offset at which
 // the query should start.
+// If the pagination type is 'LimitOffsetPagination' the value of 'Size' defines the 'limit'
+// where the value of 'Offset' defines it's 'offset'.
+// If the pagination type is 'PageNumberPagination' the value of 'Size' defines 'pageSize'
+// and the value of 'Offset' defines 'pageNumber'. The page number value starts from '1'.
 type Pagination struct {
 	// Size is a pagination value that defines 'limit' or 'page size'
 	Size int
@@ -57,11 +61,61 @@ type Pagination struct {
 	Type   PaginationType
 }
 
-// Check checks if the pagination is well formed.
-func (p *Pagination) Check() error {
+// IsValid checks if the pagination is well formed.
+func (p *Pagination) IsValid() error {
 	return p.checkValues()
 }
 
+// GetLimitOffset gets the 'limit' and 'offset' values from the given pagination.
+// If the pagination type is 'LimitOffsetPagination' then the value of 'limit' = p.Size
+// and the value of 'offset' = p.Offset.
+// In case when pagination type is 'PageNumberPagination' the 'limit' = p.Size and the
+// offset is a result of multiplication of (pageNumber - 1) * pageSize = (p.Offset - 1) * p.Size.
+// If the p.Offset is zero value then the (pageNumber - 1) value would be set previously to '0'.
+func (p *Pagination) GetLimitOffset() (limit, offset int) {
+	switch p.Type {
+	case LimitOffsetPagination:
+		limit = p.Size
+		offset = p.Offset
+	case PageNumberPagination:
+		limit = p.Size
+		// the p.Offset value is a page number that starts it's value from '1'.
+		// If it's value is zero - the offset = 0.
+		if p.Offset >= 1 {
+			offset = (p.Offset - 1) * p.Size
+		}
+	default:
+		log.Warningf("Unknown pagination type: '%v'", p.Type)
+	}
+	return limit, offset
+}
+
+// GetNumberSize gets the 'page number' and 'page size' from the pagination.
+// If the pagination type is 'PageNumberPagination' the results are just the values of pagination.
+// In case the pagination type is of 'LimitOffsetPagination' then 'limit'(Size) would be the page size
+// and the page number would be 'offset' / limit + 1. PageNumberPagination starts it's page number counting from 1.
+// If the offset % size != 0 - the offset is not dividable by the size without the rest - then the division
+// rounds down it's value.
+func (p *Pagination) GetNumberSize() (pageNumber, pageSize int) {
+	switch p.Type {
+	case LimitOffsetPagination:
+		pageSize = p.Size
+		// the default pageNumber value is '1'.
+		pageNumber = 1
+		// if the 'limit' and 'offset' values are greater than zero - compute the value of pageNumber.
+		if p.Size > 0 && p.Offset > 0 {
+			// page numbering starts from '1' thus the result would be
+			pageNumber = p.Offset/p.Size + 1
+		}
+	case PageNumberPagination:
+		pageSize = p.Size
+		pageNumber = p.Offset
+	default:
+		log.Warningf("Unknown pagination type: '%v'", p.Type)
+	}
+	return pageNumber, pageSize
+}
+
 // IsZero checks if the pagination is already set.
 func (p *Pagination) IsZero() bool {
 	return p.Size == 0 && p.Offset == 0
@@ -94,7 +148,7 @@ func (p *Pagination) FormatQuery(q ...url.Values) url.Values {
 		}
 	case PageNumberPagination:
 		number, size := p.Offset, p.Size
-		if number != 0 {
+		if number >= 1 {
 			k = ParamPageNumber
 			v = strconv.Itoa(number)
 			query.Set(k, v)
@@ -156,9 +210,9 @@ func (p *Pagination) checkPageBasedValues() error {
 		return err
 	}
 
-	if p.Offset < 0 {
+	if p.Offset <= 0 {
 		err := errors.NewDet(class.QueryPaginationValue, "invalid pagination value")
-		err.SetDetails("Pagination page-number lower than 0")
+		err.SetDetails("Pagination page-number lower equalt to 0")
 		return err
 	}
 	return nil

query/pagination_test.go

@@ -12,21 +12,21 @@ import (
 func TestPaginationFormatQuery(t *testing.T) {
 	t.Run("Paged", func(t *testing.T) {
 		p := &Pagination{Size: 10, Offset: 2, Type: PageNumberPagination}
-		require.NoError(t, p.Check())
+		require.NoError(t, p.IsValid())
 
 		q := url.Values{}
 
 		p.FormatQuery(q)
 		require.Len(t, q, 2)
 
-		assert.Equal(t, "10", q.Get(ParamPageSize), "%+v", p)
+		assert.Equal(t, "10", q.Get(ParamPageSize))
 		assert.Equal(t, "2", q.Get(ParamPageNumber))
 	})
 
 	t.Run("Limited", func(t *testing.T) {
 		p := &Pagination{Size: 10}
 
-		require.NoError(t, p.Check())
+		require.NoError(t, p.IsValid())
 
 		q := p.FormatQuery()
 		require.Len(t, q, 1)
@@ -37,7 +37,7 @@ func TestPaginationFormatQuery(t *testing.T) {
 	t.Run("Offseted", func(t *testing.T) {
 		p := &Pagination{Offset: 10}
 
-		require.NoError(t, p.Check())
+		require.NoError(t, p.IsValid())
 
 		q := p.FormatQuery()
 		require.Len(t, q, 1)
@@ -48,7 +48,7 @@ func TestPaginationFormatQuery(t *testing.T) {
 	t.Run("LimitOffset", func(t *testing.T) {
 		p := &Pagination{10, 140, LimitOffsetPagination}
 
-		require.NoError(t, p.Check())
+		require.NoError(t, p.IsValid())
 
 		q := p.FormatQuery()
 		require.Len(t, q, 2)
@@ -57,3 +57,53 @@ func TestPaginationFormatQuery(t *testing.T) {
 		assert.Equal(t, "140", q.Get(ParamPageOffset))
 	})
 }
+
+// TestGetLimitOffset tests the pagination GetLimitOffset method.
+func TestGetLimitOffset(t *testing.T) {
+	// At first check the default 'LimitOffsetPagination'.
+	p := &Pagination{Size: 1, Offset: 10}
+	limit, offset := p.GetLimitOffset()
+	assert.Equal(t, 1, limit)
+	assert.Equal(t, 10, offset)
+
+	// Check the pagination with PageNumberPagination type.
+	t.Run("PageNumber", func(t *testing.T) {
+		p = &Pagination{Type: PageNumberPagination, Size: 3, Offset: 9}
+		limit, offset = p.GetLimitOffset()
+
+		// the offset would be (pageNumber - 1) * pageSize = 8 * 3 = 24
+		assert.Equal(t, 24, offset)
+		assert.Equal(t, 3, limit)
+
+		// Check the pagination without page number defined.
+		p = &Pagination{Type: PageNumberPagination, Size: 10}
+		limit, offset = p.GetLimitOffset()
+
+		assert.Equal(t, 0, offset)
+		assert.Equal(t, 10, limit)
+	})
+}
+
+// TestGetNumberSize tests the pagination GetNumberSize method.
+func TestGetNumberSize(t *testing.T) {
+	// At first check the 'PageNumberPagination'.
+	p := &Pagination{Type: PageNumberPagination, Size: 3, Offset: 9}
+	number, size := p.GetNumberSize()
+
+	assert.Equal(t, 9, number)
+	assert.Equal(t, 3, size)
+
+	t.Run("LimitOffsetTyped", func(t *testing.T) {
+		// Check the 'LimitOffsetPagination' with defined fields.
+		p = &Pagination{Size: 3, Offset: 10}
+		number, size = p.GetNumberSize()
+		assert.Equal(t, 3, size)
+		assert.Equal(t, 4, number)
+
+		// Check the values with zero values.
+		p = &Pagination{Size: 10}
+		number, size = p.GetNumberSize()
+		assert.Equal(t, 10, size)
+		assert.Equal(t, 1, number)
+	})
+}

query/process-lists.go

@@ -80,3 +80,16 @@ func beforeListFunc(ctx context.Context, s *Scope) error {
 
 	return nil
 }
+
+// checkPaginationFunc is the process func that checks the validity of the pagination
+func checkPaginationFunc(ctx context.Context, s *Scope) error {
+	if _, ok := s.StoreGet(processErrorKey); ok {
+		return nil
+	}
+
+	if s.Pagination == nil {
+		return nil
+	}
+
+	return s.Pagination.IsValid()
+}

query/processor.go

@@ -47,6 +47,7 @@ func init() {
 	RegisterProcessFunc(ProcessHookAfterGet, afterGetFunc)
 
 	// List
+	RegisterProcessFunc(ProcessCheckPagination, checkPaginationFunc)
 	RegisterProcessFunc(ProcessHookBeforeList, beforeListFunc)
 	RegisterProcessFunc(ProcessList, listFunc)
 	RegisterProcessFunc(ProcessHookAfterList, afterListFunc)

query/scope-pagination.go

@@ -15,7 +15,7 @@ func (s *Scope) Limit(limit, offset int) error {
 	}
 
 	s.Pagination = &Pagination{Size: limit, Offset: offset}
-	if err := s.Pagination.Check(); err != nil {
+	if err := s.Pagination.IsValid(); err != nil {
 		return err
 	}
 	return nil
@@ -27,8 +27,8 @@ func (s *Scope) Page(number, size int) error {
 		return errors.NewDet(class.QueryPaginationAlreadySet, "pagination already set")
 	}
 
-	s.Pagination = &Pagination{Size: size, Offset: number}
-	if err := s.Pagination.Check(); err != nil {
+	s.Pagination = &Pagination{Size: size, Offset: number, Type: PageNumberPagination}
+	if err := s.Pagination.IsValid(); err != nil {
 		return err
 	}
 	return nil