binder

Parameter Binding Verification Plugin for Struct Handler.

Usage

import "github.com/andeya/erpc/v7/plugin/binder"

Param-Tags

tag	key	required	value	desc
param	meta	no	(name e.g.param:"<meta:id>")	It indicates that the parameter is from the meta.
param	swap	no	name (e.g.param:"<swap:id>")	It indicates that the parameter is from the context swap.
param	desc	no	(e.g.param:"<desc:id>")	Parameter Description
param	len	no	(e.g.param:"<len:3:6>")	Length range [a,b] of parameter's value
param	range	no	(e.g.param:"<range:0:10>")	Numerical range [a,b] of parameter's value
param	nonzero	no	-	Not allowed to zero
param	regexp	no	(e.g.param:"<regexp:^\\w+$>")	Regular expression validation
param	stat	no	(e.g.param:"<stat:100002:wrong password format>")	Custom error code and message

NOTES:

• param:"-" means ignore
• Encountered untagged exportable anonymous structure field, automatic recursive resolution
• Parameter name is the name of the structure field converted to snake format
• If the parameter is not from meta or swap, it is the default from the body
• Support for multiple rule combinations, e.g.param:"<regexp:^\\w+$><len:6:8><stat:100002:wrong password format>"

Field-Types

base	slice	special
string	[]string	[][]byte
byte	[]byte	[][]uint8
uint8	[]uint8	struct
bool	[]bool
int	[]int
int8	[]int8
int16	[]int16
int32	[]int32
int64	[]int64
uint8	[]uint8
uint16	[]uint16
uint32	[]uint32
uint64	[]uint64
float32	[]float32
float64	[]float64

Test

package binder_test

import (
	"testing"
	"time"

	"github.com/andeya/erpc/v7"
	"github.com/andeya/erpc/v7/plugin/binder"
)

type (
	Arg struct {
		A int
		B int    `param:"<range:1:100>"`
		C string `param:"<regexp:^[1-9]\\d*$>"`
		Query
		XyZ       string  `param:"<meta><nonzero><stat: 100002: Parameter cannot be empty>"`
		SwapValue float32 `param:"<swap><nonzero>"`
	}
	Query struct {
		X string `param:"<meta:_x>"`
	}
)

type P struct{ erpc.CallCtx }

func (p *P) Divide(arg *Arg) (int, *erpc.Status) {
	erpc.Infof("meta arg _x: %s, xy_z: %s, swap_value: %v", arg.Query.X, arg.XyZ, arg.SwapValue)
	return arg.A / arg.B, nil
}

type SwapPlugin struct{}

func (s *SwapPlugin) Name() string {
	return "swap_plugin"
}
func (s *SwapPlugin) PostReadCallBody(ctx erpc.ReadCtx) *erpc.Status {
	ctx.Swap().Store("swap_value", 123)
	return nil
}

func TestBinder(t *testing.T) {
	bplugin := binder.NewStructArgsBinder(nil)
	srv := erpc.NewPeer(
		erpc.PeerConfig{ListenPort: 9090},
	)
	srv.PluginContainer().AppendRight(bplugin)
	srv.RouteCall(new(P), new(SwapPlugin))
	go srv.ListenAndServe()
	time.Sleep(time.Second)

	cli := erpc.NewPeer(erpc.PeerConfig{})
	sess, stat := cli.Dial(":9090")
	if !stat.OK() {
		t.Fatal(stat)
	}
	var result int
	stat = sess.Call("/p/divide", &Arg{
		A: 10,
		B: 2,
		C: "3",
	},
		&result,
		erpc.WithSetMeta("_x", "testmeta_x"),
		erpc.WithSetMeta("xy_z", "testmeta_xy_z"),
	).Status()
	if !stat.OK() {
		t.Fatal(stat)
	}
	t.Logf("10/2=%d", result)
	stat = sess.Call("/p/divide", &Arg{
		A: 10,
		B: 5,
		C: "3",
	}, &result).Status()
	if stat.OK() {
		t.Fatal(stat)
	}
	t.Logf("10/5 error:%v", stat)
	stat = sess.Call("/p/divide", &Arg{
		A: 10,
		B: 0,
		C: "3",
	}, &result).Status()
	if stat.OK() {
		t.Fatal(stat)
	}
	t.Logf("10/0 error:%v", stat)
}

test command:

go test -v -run=TestBinder