feat: adds the ability to control SelectBuilder

alex-poliushkin · alex-poliushkin · commit 420a6987aeb3 · 2021-12-24T22:42:44.000+03:00
diff --git a/builder.go b/builder.go
@@ -9,7 +9,7 @@ import (
 
 type Builder interface {
 	// Build builds sql query
-	Build(ctx context.Context, query *qparser.Query) (Sqlizer, error)
+	Build(ctx context.Context, query *qparser.Query, sb ...*SelectBuilder) (*SelectBuilder, error)
 }
 
 // Extension is used in order to extend a builder
@@ -54,9 +54,20 @@ func NewResourceSelectBuilder(
 }
 
 // Build builds sql query which depends on the applied options
-func (s *ResourceSelectBuilder) Build(ctx context.Context, query *qparser.Query) (Sqlizer, error) {
-	var selectFields []string
-	sb := new(SelectBuilder)
+func (s *ResourceSelectBuilder) Build(
+	ctx context.Context,
+	query *qparser.Query,
+	sb ...*SelectBuilder,
+) (*SelectBuilder, error) {
+	var (
+		selectFields []string
+		b            *SelectBuilder
+	)
+	if len(sb) > 0 {
+		b = sb[0]
+	} else {
+		b = new(SelectBuilder)
+	}
 	if fields, ok := query.Fields.FieldsByResource(s.resourceName); ok {
 		fields, err := s.translator(fields)
 		if err != nil {
@@ -71,15 +82,15 @@ func (s *ResourceSelectBuilder) Build(ctx context.Context, query *qparser.Query)
 			return nil, fmt.Errorf("field %q not allowed for selection criteria", field)
 		}
 	}
-	sb.Select(selectFields).From(s.resourceName)
+	b.Select(selectFields).From(s.resourceName)
 	conditions, err := s.retrieveFilterConditions(query)
 	if err != nil {
 		return nil, err
 	}
-	if len(conditions) == 0 {
-		sb.Where(alwaysTrue)
+	if len(conditions) == 0 && len(b.WhereParts) == 0 {
+		b.Where(alwaysTrue)
 	} else {
-		sb.Where(conditions...)
+		b.Where(conditions...)
 	}
 	sortList := make([]qparser.Sort, len(query.Sort))
 	sortFields := make([]string, len(query.Sort))
@@ -105,14 +116,14 @@ func (s *ResourceSelectBuilder) Build(ctx context.Context, query *qparser.Query)
 		sortList[i].FieldName = sortFields[i]
 	}
 	if len(sortList) > 0 {
-		sb.OrderBy(OrderBy(sortList))
+		b.OrderBy(OrderBy(sortList))
 	}
 	for _, extension := range s.extensions {
-		if err = extension(ctx, query, sb); err != nil {
+		if err = extension(ctx, query, b); err != nil {
 			return nil, err
 		}
 	}
-	return sb, nil
+	return b, nil
 }
 
 func (s *ResourceSelectBuilder) retrieveFilterConditions(query *qparser.Query) ([]Sqlizer, error) {
diff --git a/builder_test.go b/builder_test.go
@@ -15,6 +15,7 @@ type resourceBuilderTest struct {
 	sql         string
 	args        []interface{}
 	expectedErr bool
+	sb          func() *SelectBuilder
 }
 
 const (
@@ -85,6 +86,16 @@ var resourceBuilderTests = []resourceBuilderTest{
 		query:       fmt.Sprintf("fields[%s]=updatedAt", resourceName),
 		expectedErr: true,
 	},
+	{
+		title: "With extra params",
+		query: fmt.Sprintf("fields[%s]=%s,%s", resourceName, resourceFieldID, resourceFieldTitle),
+		sql:   fmt.Sprintf("SELECT %s, %s FROM %s WHERE id = ?", resourceFieldID, resourceFieldTitle, resourceName),
+		args:  []interface{}{"1"},
+		sb: func() *SelectBuilder {
+			sb := new(SelectBuilder)
+			return sb.Where(&RawSqlWithArgs{"id = ?", []interface{}{"1"}})
+		},
+	},
 }
 
 func TestNewResourceSelectBuilder(t *testing.T) {
@@ -149,7 +160,11 @@ func TestNewResourceSelectBuilder(t *testing.T) {
 		if err != nil {
 			t.Fatalf("%sqparser.ParseQuery(%q) returned unexpected error: %s", meta, tt.query, err)
 		}
-		sqlizer, err := builder.Build(ctx, query)
+		var sb []*SelectBuilder
+		if tt.sb != nil {
+			sb = []*SelectBuilder{tt.sb()}
+		}
+		sqlizer, err := builder.Build(ctx, query, sb...)
 		if !tt.expectedErr && err != nil {
 			t.Errorf("%sunexpected error %s", meta, err)
 			continue
diff --git a/examples/basic/main.go b/examples/basic/main.go
diff --git a/examples/custom_params/main.go b/examples/custom_params/main.go
@@ -0,0 +1,66 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"github.com/velmie/qparser"
+	"log"
+
+	"github.com/velmie/q2sql"
+	"github.com/velmie/q2sql/condition"
+	"github.com/velmie/q2sql/extension"
+)
+
+func main() {
+	translator := q2sql.MapTranslator(map[string]string{
+		"id":        "id",
+		"title":     "title",
+		"body":      "body",
+		"author":    "author",
+		"createdAt": "created_at",
+	})
+
+	allowedConditionsByField := q2sql.AllowedConditions{
+		"id": []string{condition.NameIn},
+	}
+	builder := q2sql.NewResourceSelectBuilder(
+		"articles",
+		translator,
+		q2sql.AllowSelectFields([]string{"id", "title", "author"}),
+		q2sql.AllowFiltering(
+			allowedConditionsByField,
+			condition.DefaultConditionMap,
+			q2sql.DefaultFilterExpressionParser,
+		),
+		q2sql.AllowSortingByFields([]string{"created_at", "title"}),
+		q2sql.Extend(extension.LimitOffsetPagination(extension.Unlimited, extension.Unlimited)),
+	)
+
+	qstr := "?fields[articles]=id,title,author&filter[id]=in:1,2,3,4,5&sort=-createdAt,title&page[limit]=100"
+	query, _ := qparser.ParseQuery(qstr)
+
+	// It's possible to pass select builder
+	sb := new(q2sql.SelectBuilder)
+	// and define custom conditions
+	sb.Where(&q2sql.Eq{"author", "Alan Turing"})
+
+	// not necessary to declare new variable since the "sb" already points to the select builder
+	_, err := builder.Build(context.Background(), query, sb)
+	if err != nil {
+		log.Fatal("failed to build query", err)
+	}
+	// or rewrite some parts, for example the line below clears sorting
+	sb.OrderByParts = nil
+
+	sqlStr, args, err := sb.ToSql()
+	if err != nil {
+		log.Fatal("failed to build SQL query", err)
+	}
+	fmt.Println(sqlStr)
+	fmt.Println(args)
+	// prints
+	/*
+		SELECT id, title, author FROM articles WHERE author = ? AND id IN (?,?,?,?,?) LIMIT 100
+		[Alan Turing 1 2 3 4 5]
+	*/
+}
diff --git a/readme.md b/readme.md
@@ -208,3 +208,14 @@ The Extension accesses * q2sql.SelectBuilder and can use it to modify the result
 		[1 2 3 4 5]
 	 */
 ```
+
+In order to apply custom conditions you may pass select builder to the resource select builder.
+
+```go
+    sb := new(q2sql.SelectBuilder)
+	sb.Where(&q2sql.Eq{"author", "Alan Turing"})
+    
+    _, err := builder.Build(context.Background(), query, sb)
+    ...
+    
+```
