fabric-samples/asset-transfer-basic/rest-api-go/web/invoke.go

package web

import (
	"encoding/json"
	"fmt"
	"net/http"

	"github.com/hyperledger/fabric-gateway/pkg/client"
)

// Invoke handles chaincode invoke requests.
func (setup *OrgSetup) Invoke(w http.ResponseWriter, r *http.Request) {
	fmt.Println("Received Invoke request")
	if err := r.ParseForm(); err != nil {
		fmt.Fprintf(w, "ParseForm() err: %s", err)
		return
	}
	chainCodeName := r.FormValue("chaincodeid")
	channelID := r.FormValue("channelid")
	function := r.FormValue("function")
	args := r.Form["args"]

	if len(args) == 1 {
		var parsed []string
		err := json.Unmarshal([]byte(args[0]), &parsed)
		if err == nil {
			args = parsed
		} else {
			fmt.Printf("Warning: failed to parse args as JSON: %s\n", err)
		}
	}

	if len(args) == 0 {
		fmt.Fprintf(w, "Error: args is empty")
		return
	}

	fmt.Printf("channel: %s, chaincode: %s, function: %s, args: %s\n", channelID, chainCodeName, function, args)
	network := setup.Gateway.GetNetwork(channelID)
	contract := network.GetContract(chainCodeName)
	txn_proposal, err := contract.NewProposal(function, client.WithArguments(args...))
	if err != nil {
		fmt.Fprintf(w, "Error creating txn proposal: %s", err)
		return
	}
	txn_endorsed, err := txn_proposal.Endorse()
	if err != nil {
		fmt.Fprintf(w, "Error endorsing txn: %s", err)
		return
	}
	txn_committed, err := txn_endorsed.Submit()
	if err != nil {
		fmt.Fprintf(w, "Error submitting transaction: %s", err)
		return
	}
	fmt.Fprintf(w, "Transaction ID : %s Response: %s", txn_committed.TransactionID(), txn_endorsed.Result())
}