Implement pagination and simple filtering

pkg/api/api.go

@@ -125,9 +125,37 @@ func GetTableRows(c *gin.Context) {
 		Offset:     offset,
 		SortColumn: c.Request.FormValue("sort_column"),
 		SortOrder:  c.Request.FormValue("sort_order"),
+		Where:      c.Request.FormValue("where"),
 	}
 
 	res, err := DbClient.TableRows(c.Params.ByName("table"), opts)
+	if err != nil {
+		c.JSON(400, NewError(err))
+		return
+	}
+
+	countRes, err := DbClient.TableRowsCount(c.Params.ByName("table"), opts)
+	if err != nil {
+		c.JSON(400, NewError(err))
+		return
+	}
+
+	numFetch := int64(opts.Limit)
+	numOffset := int64(opts.Offset)
+	numRows := countRes.Rows[0][0].(int64)
+	numPages := numRows / numFetch
+
+	if numPages*numFetch < numRows {
+		numPages++
+	}
+
+	res.Pagination = &client.Pagination{
+		Rows:    numRows,
+		Page:    (numOffset / numFetch) + 1,
+		Pages:   numPages,
+		PerPage: numFetch,
+	}
+
 	serveResult(res, err, c)
 }
 

pkg/api/helpers.go

@@ -47,7 +47,7 @@ func parseIntFormValue(c *gin.Context, name string, defValue int) (int, error) {
 		return defValue, fmt.Errorf("%s must be a number", name)
 	}
 
-	if num < 1 {
+	if num < 1 && defValue != 0 {
 		return defValue, fmt.Errorf("%s must be greated than 0", name)
 	}
 

pkg/client/client.go

@@ -21,6 +21,7 @@ type Client struct {
 
 // Struct to hold table rows browsing options
 type RowsOptions struct {
+	Where      string // Custom filter
 	Offset     int    // Number of rows to skip
 	Limit      int    // Number of rows to fetch
 	SortColumn string // Column to sort by
@@ -99,6 +100,10 @@ func (client *Client) Table(table string) (*Result, error) {
 func (client *Client) TableRows(table string, opts RowsOptions) (*Result, error) {
 	sql := fmt.Sprintf(`SELECT * FROM "%s"`, table)
 
+	if opts.Where != "" {
+		sql += fmt.Sprintf(" WHERE %s", opts.Where)
+	}
+
 	if opts.SortColumn != "" {
 		if opts.SortOrder == "" {
 			opts.SortOrder = "ASC"
@@ -118,6 +123,16 @@ func (client *Client) TableRows(table string, opts RowsOptions) (*Result, error)
 	return client.query(sql)
 }
 
+func (client *Client) TableRowsCount(table string, opts RowsOptions) (*Result, error) {
+	sql := fmt.Sprintf(`SELECT COUNT(1) FROM "%s"`, table)
+
+	if opts.Where != "" {
+		sql += fmt.Sprintf(" WHERE %s", opts.Where)
+	}
+
+	return client.query(sql)
+}
+
 func (client *Client) TableInfo(table string) (*Result, error) {
 	return client.query(statements.PG_TABLE_INFO, table)
 }

pkg/client/result.go

@@ -11,9 +11,17 @@ import (
 
 type Row []interface{}
 
+type Pagination struct {
+	Rows    int64 `json:"rows_count"`
+	Page    int64 `json:"page"`
+	Pages   int64 `json:"pages_count"`
+	PerPage int64 `json:"per_page"`
+}
+
 type Result struct {
-	Columns []string `json:"columns"`
-	Rows    []Row    `json:"rows"`
+	Pagination *Pagination `json:"pagination,omitempty"`
+	Columns    []string    `json:"columns"`
+	Rows       []Row       `json:"rows"`
 }
 
 // Due to big int number limitations in javascript, numbers should be encoded