Extended REST API: PUT, DELETE (campaign), POST (donation)

src/myaktion/handler/campaign.go

@@ -36,6 +36,61 @@ func GetCampaigns(w http.ResponseWriter, _ *http.Request) {
 	sendJson(w, campaigns)
 }
 
+func UpdateCampaign(w http.ResponseWriter, r *http.Request) {
+	//extract id from url path
+	id, err := getId(r)
+	if err != nil {
+		//Bad Request
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	//Read Body
+	var campaign *model.Campaign
+	campaign, err = getCampaign(r)
+	if err != nil {
+		log.Printf("Error calling service UpdateCampaign: %v", err)
+		http.Error(w, err.Error(), http.StatusBadRequest)
+	}
+	//Call service function
+	campaign, err = service.UpdateCampaign(id, campaign)
+	if err != nil {
+		log.Errorf("Failure updating campaign with ID %v: %v", id, err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if campaign == nil {
+		http.Error(w, "404 campaign not found", http.StatusNotFound)
+		log.Errorf("Campaign with ID %v not found: %v", id, err)
+		return
+	}
+	//Send result OK
+	sendJson(w, campaign)
+}
+
+func DeleteCampaign(w http.ResponseWriter, r *http.Request) {
+	//extract id from url path
+	id, err := getId(r)
+	if err != nil {
+		//Bad Request
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	//Call service function DeleteCampaign
+	var campaign *model.Campaign
+	campaign, err = service.DeleteCampaign(id)
+	if err != nil {
+		log.Errorf("Failure deleting campaign with ID %v: %v", id, err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if campaign == nil {
+		log.Errorf("Campaign with ID %v not found: %v", id, err)
+		http.Error(w, "404 campaign not found", http.StatusNotFound)
+		return
+	}
+	sendJson(w, result{Success: "OK"})
+}
+
 func getCampaign(r *http.Request) (*model.Campaign, error) {
 	var campaign model.Campaign
 	err := json.NewDecoder(r.Body).Decode(&campaign)

src/myaktion/handler/donation.go

+package handler
+
+import (
+	"encoding/json"
+	"net/http"
+
+	log "github.com/sirupsen/logrus"
+	"gitlab.reutlingen-university.de/go-exercises/myaktion-go-ss25/src/myaktion/model"
+	"gitlab.reutlingen-university.de/go-exercises/myaktion-go-ss25/src/myaktion/service"
+)
+
+func AddDonation(w http.ResponseWriter, r *http.Request) {
+	id, err := getId(r)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	donation, err := getDonation(r)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	// TODO: if the campaign doesn't exist, return 404 - don't show FK error
+	err = service.AddDonation(id, donation)
+	if err != nil {
+		log.Errorf("Failure adding donation to campaign with ID %v: %v", id, err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	sendJson(w, donation)
+}
+
+func getDonation(r *http.Request) (*model.Donation, error) {
+	var donation model.Donation
+	err := json.NewDecoder(r.Body).Decode(&donation)
+	if err != nil {
+		log.Errorf("Can't serialize request body to donation struct: %v", err)
+		return nil, err
+	}
+	return &donation, nil
+}

src/myaktion/main.go

@@ -30,6 +30,9 @@ func main() {
 	router.HandleFunc("/health", handler.Health).Methods("GET")
 	router.HandleFunc("/campaigns", handler.CreateCampaign).Methods("POST")
 	router.HandleFunc("/campaigns", handler.GetCampaigns).Methods("GET")
+	router.HandleFunc("/campaigns/{id}", handler.UpdateCampaign).Methods("PUT")
+	router.HandleFunc("/campaigns/{id}", handler.DeleteCampaign).Methods("DELETE")
+	router.HandleFunc("/campaigns/{id}/donation", handler.AddDonation).Methods("POST")
 	if err := http.ListenAndServe(":8000", router); err != nil {
 		log.Fatal(err)
 	}

src/myaktion/service/campaign.go

 package service
 
 import (
+	"errors"
+
 	log "github.com/sirupsen/logrus"
+	"gorm.io/gorm"
 
 	"gitlab.reutlingen-university.de/go-exercises/myaktion-go-ss25/src/myaktion/db"
 	"gitlab.reutlingen-university.de/go-exercises/myaktion-go-ss25/src/myaktion/model"
@@ -17,6 +20,61 @@ func CreateCampaign(campaign *model.Campaign) error {
 	return nil
 }
 
+func UpdateCampaign(id uint, campaign *model.Campaign) (*model.Campaign, error) {
+	existingCampaign, err := GetCampaign(id)
+	if existingCampaign == nil || err != nil {
+		return existingCampaign, err
+	}
+	existingCampaign.Name = campaign.Name
+	existingCampaign.OrganizerName = campaign.OrganizerName
+	existingCampaign.TargetAmount = campaign.TargetAmount
+	existingCampaign.DonationMinimum = campaign.DonationMinimum
+	existingCampaign.Account = campaign.Account
+	result := db.DB.Save(existingCampaign)
+	if result.Error != nil {
+		return nil, result.Error
+	}
+	entry := log.WithField("ID", id)
+	entry.Info("Successfully updated campaign.")
+	entry.Tracef("Updated: %v", existingCampaign)
+	return existingCampaign, nil
+}
+
+func PatchCampaign(id uint, campaign *model.Campaign) (*model.Campaign, error) {
+	existingCampaign, err := GetCampaign(id)
+	if existingCampaign == nil || err != nil {
+		return existingCampaign, err
+	}
+	existingCampaign.Name = campaign.Name
+	existingCampaign.OrganizerName = campaign.OrganizerName
+	existingCampaign.TargetAmount = campaign.TargetAmount
+	existingCampaign.DonationMinimum = campaign.DonationMinimum
+	existingCampaign.Account = campaign.Account
+	result := db.DB.Save(existingCampaign)
+	if result.Error != nil {
+		return nil, result.Error
+	}
+	entry := log.WithField("ID", id)
+	entry.Info("Successfully updated campaign.")
+	entry.Tracef("Updated: %v", existingCampaign)
+	return existingCampaign, nil
+}
+
+func DeleteCampaign(id uint) (*model.Campaign, error) {
+	campaign, err := GetCampaign(id)
+	if campaign == nil || err != nil {
+		return campaign, err
+	}
+	result := db.DB.Delete(campaign)
+	if result.Error != nil {
+		return nil, result.Error
+	}
+	entry := log.WithField("ID", id)
+	entry.Info("Successfully deleted campaign.")
+	entry.Tracef("Deleted: %v", campaign)
+	return campaign, nil
+}
+
 func GetCampaigns() ([]model.Campaign, error) {
 	var campaigns []model.Campaign
 	result := db.DB.Preload("Donations").Find(&campaigns)
@@ -26,3 +84,16 @@ func GetCampaigns() ([]model.Campaign, error) {
 	log.Tracef("Retrieved: %v", campaigns)
 	return campaigns, nil
 }
+
+func GetCampaign(id uint) (*model.Campaign, error) {
+	campaign := new(model.Campaign)
+	result := db.DB.Preload("Donations").First(campaign, id)
+	if errors.Is(result.Error, gorm.ErrRecordNotFound) {
+		return nil, nil
+	}
+	if result.Error != nil {
+		return nil, result.Error
+	}
+	log.Tracef("Retrieved: %v", campaign)
+	return campaign, nil
+}

src/myaktion/service/donation.go

+package service
+
+import (
+	log "github.com/sirupsen/logrus"
+	"gitlab.reutlingen-university.de/go-exercises/myaktion-go-ss25/src/myaktion/db"
+	"gitlab.reutlingen-university.de/go-exercises/myaktion-go-ss25/src/myaktion/model"
+)
+
+func AddDonation(campaignId uint, donation *model.Donation) error {
+	donation.CampaignID = campaignId
+	result := db.DB.Create(donation)
+	if result.Error != nil {
+		return result.Error
+	}
+	entry := log.WithField("ID", campaignId)
+	entry.Info("Successfully added new donation to campaign in database.")
+	entry.Tracef("Stored: %v", donation)
+	return nil
+}