Add quality of life methods for existing types

assets/assetListFuncs.go

@@ -7,7 +7,7 @@ func AssetTypeList() []AssetType {
 	return listCopy
 }
 
-// FetchAssetType returns a pointer to the AssetType object or nil if tx is not found
+// FetchAssetType returns a pointer to the AssetType object or nil if asset type is not found
 func FetchAssetType(assetTypeTag string) *AssetType {
 	for _, assetType := range assetTypeList {
 		if assetType.Tag == assetTypeTag {

assets/assetType.go

@@ -51,6 +51,16 @@ func (t AssetType) HasProp(propTag string) bool {
 	return false
 }
 
+// GetPropDef fetches the propDef with tag propTag
+func (t AssetType) GetPropDef(propTag string) *AssetProp {
+	for _, prop := range t.Props {
+		if prop.Tag == propTag {
+			return &prop
+		}
+	}
+	return nil
+}
+
 // IsPrivate returns true if asset is in a private collection
 func (t AssetType) IsPrivate() bool {
 	return len(t.Readers) > 0

assets/existsInLedger.go

@@ -23,3 +23,22 @@ func (a *Asset) ExistsInLedger(stub shim.ChaincodeStubInterface) (bool, errors.I
 
 	return false, nil
 }
+
+// ExistsInLedger checks if asset referenced by key already exists
+func (k *Key) ExistsInLedger(stub shim.ChaincodeStubInterface) (bool, errors.ICCError) {
+	var assetBytes []byte
+	var err error
+	if k.IsPrivate() {
+		assetBytes, err = stub.GetPrivateDataHash(k.TypeTag(), k.Key())
+	} else {
+		assetBytes, err = stub.GetState(k.Key())
+	}
+	if err != nil {
+		return false, errors.WrapErrorWithStatus(err, "unable to check asset existence", 400)
+	}
+	if assetBytes != nil {
+		return true, nil
+	}
+
+	return false, nil
+}

assets/getProp.go

@@ -0,0 +1,7 @@
+package assets
+
+// GetProp returns the prop value. It returns nil if it doesn't exist.
+func (a Asset) GetProp(propTag string) interface{} {
+	val, _ := a[propTag]
+	return val
+}

assets/setProp.go

@@ -0,0 +1,34 @@
+package assets
+
+import (
+	"fmt"
+
+	"github.com/goledgerdev/cc-tools/errors"
+)
+
+// SetProp sets the prop value with proper validation.
+func (a *Asset) SetProp(propTag string, value interface{}) errors.ICCError {
+	if len(propTag) == 0 {
+		return errors.NewCCError("propTag cannot be empty", 500)
+	}
+	if propTag[0] == '@' {
+		return errors.NewCCError("cannot modify internal properties", 500)
+	}
+	assetType := a.Type()
+	if assetType == nil {
+		return errors.NewCCError("asset type does not exist", 500)
+	}
+	propDef := assetType.GetPropDef(propTag)
+	if propDef == nil {
+		return errors.NewCCError(fmt.Sprintf("asset type '%s' does not have prop named '%s'", assetType.Tag, propTag), 500)
+	}
+	propType := DataTypeMap()[propDef.DataType]
+
+	_, parsedVal, err := propType.Parse(value)
+	if err != nil {
+		return errors.WrapError(err, fmt.Sprintf("invalid '%s' value", propTag))
+	}
+	(*a)[propTag] = parsedVal
+
+	return nil
+}