Address reviewer's feedback

* Add assetFromJson, mptIssueFromJson
* Minor refactoring

include/xrpl/protocol/Asset.h

@@ -169,6 +169,9 @@ to_string(Asset const& asset);
 bool
 validJSONAsset(Json::Value const& jv);
 
+Asset
+assetFromJson(Json::Value const& jv);
+
 }  // namespace ripple
 
 #endif  // RIPPLE_PROTOCOL_ASSET_H_INCLUDED

include/xrpl/protocol/MPTIssue.h

@@ -90,6 +90,9 @@ to_json(MPTIssue const& mptIssue);
 std::string
 to_string(MPTIssue const& mptIssue);
 
+MPTIssue
+mptIssueFromJson(Json::Value const& jv);
+
 }  // namespace ripple
 
 #endif  // RIPPLE_PROTOCOL_MPTISSUE_H_INCLUDED

include/xrpl/protocol/detail/transactions.macro

@@ -400,7 +400,7 @@ TRANSACTION(ttMPTOKEN_ISSUANCE_DESTROY, 55, MPTokenIssuanceDestroy, ({
     {sfMPTokenIssuanceID, soeREQUIRED},
 }))
 
-/** This transaction type sets a MPTokensIssuance instance */
+/** This transaction type sets flags on a MPTokensIssuance instance */
 TRANSACTION(ttMPTOKEN_ISSUANCE_SET, 56, MPTokenIssuanceSet, ({
     {sfMPTokenIssuanceID, soeREQUIRED},
     {sfMPTokenHolder, soeOPTIONAL},

include/xrpl/protocol/jss.h

@@ -58,6 +58,8 @@ JSS(AssetPrice);           // in: Oracle
 JSS(AuthAccount);          // in: AMM Auction Slot
 JSS(AuthAccounts);         // in: AMM Auction Slot
 JSS(BaseAsset);            // in: Oracle
+JSS(BidMax);               // in: AMM Bid
+JSS(BidMin);               // in: AMM Bid
 JSS(Bridge);               // ledger type.
 JSS(Check);                // ledger type.
 JSS(ClearFlag);            // field.
@@ -76,8 +78,6 @@ JSS(LastLedgerSequence);   // in: TransactionSign; field
 JSS(LastUpdateTime);       // field.
 JSS(LedgerHashes);         // ledger type.
 JSS(LimitAmount);          // field.
-JSS(BidMax);               // in: AMM Bid
-JSS(BidMin);               // in: AMM Bid
 JSS(MPToken);              // ledger type.
 JSS(MPTokenIssuance);      // ledger type.
 JSS(NetworkID);            // field.

src/libxrpl/protocol/Asset.cpp

@@ -58,4 +58,16 @@ validJSONAsset(Json::Value const& jv)
     return jv.isMember(jss::currency);
 }
 
+Asset
+assetFromJson(Json::Value const& v)
+{
+    if (!v.isMember(jss::currency) && !v.isMember(jss::mpt_issuance_id))
+        Throw<std::runtime_error>(
+            "assetFromJson must contain currency or mpt_issuance_id");
+
+    if (v.isMember(jss::currency))
+        return issueFromJson(v);
+    return mptIssueFromJson(v);
+}
+
 }  // namespace ripple

src/libxrpl/protocol/Issue.cpp

@@ -95,6 +95,12 @@ issueFromJson(Json::Value const& v)
             "issueFromJson can only be specified with an 'object' Json value");
     }
 
+    if (v.isMember(jss::mpt_issuance_id))
+    {
+        Throw<std::runtime_error>(
+            "issueFromJson, Issue should not have mpt_issuance_id");
+    }
+
     Json::Value const curStr = v[jss::currency];
     Json::Value const issStr = v[jss::issuer];
 

src/libxrpl/protocol/MPTIssue.cpp

@@ -17,7 +17,7 @@
 */
 //==============================================================================
 
-#include <xrpl/protocol/Indexes.h>
+#include <xrpl/json/json_errors.h>
 #include <xrpl/protocol/MPTIssue.h>
 #include <xrpl/protocol/jss.h>
 
@@ -71,4 +71,37 @@ to_string(MPTIssue const& mptIssue)
     return to_string(mptIssue.getMptID());
 }
 
+MPTIssue
+mptIssueFromJson(Json::Value const& v)
+{
+    if (!v.isObject())
+    {
+        Throw<std::runtime_error>(
+            "mptIssueFromJson can only be specified with an 'object' Json "
+            "value");
+    }
+
+    if (v.isMember(jss::currency) || v.isMember(jss::issuer))
+    {
+        Throw<std::runtime_error>(
+            "mptIssueFromJson, MPTIssue should not have currency or issuer");
+    }
+
+    Json::Value const idStr = v[jss::mpt_issuance_id];
+
+    if (!idStr.isString())
+    {
+        Throw<Json::error>(
+            "mptIssueFromJson MPTID must be a string Json value");
+    }
+
+    MPTID id;
+    if (!id.parseHex(idStr.asString()))
+    {
+        Throw<Json::error>("mptIssueFromJson MPTID is invalid");
+    }
+
+    return MPTIssue{id};
+}
+
 }  // namespace ripple