GeneXus adds the support of Hyperledger Fabric to facilitate cross-industry projects that require integration with an enterprise-grade blockchain.
That GeneXus adds Hyperledger to its supported Data Stores gives the developer the chance to create solutions that integrate to a blockchain as easily as to any other relational DBMS, Odata services and other data sources.
GeneXus generates the application with its services that connect to the middleware, and, to enforce business rules, also generates the smart contracts using chaincode.
1) Add HyperLedger as a Data Store
Go to Preferences > My Knowledge Base > My Version > My Environment > Data Stores > New Data Store > Service
Set properties
- ServerName: <Server uri>
- UserID: <Username>
- User Password <Password>
- Datastore Provider: HyperLedger
- Chaincode Prefix: <Unique identifier of the entities of this KB / Environment in the Hyperledger installation>
- Chaincode Postfix: <To help identify easily the entities of this KB / Environment in the Hyperledger installation>
- Chaincode Case Sensitive: True|False
2) Create a Transaction
Customer
{
CustomerId*
CustomerName
}
#Rules
error("Customer Name must not be empty") if CustomerName.IsEmpty();
3) Define a DataView
You can defined it 'by hand' or make GeneXus define it.
Right-click on the 'Customer' Transaction > Link to Service Data View. This will create the following dataview:
Customer_DV
{
CustomerId*
CustomerName
}
#DataStores
Service with Properties {Name= BlockChainTest_customer, Use Externalname = Yes}
Properties of Customer_DV:
Associated Table = Customer
Datastore = HyperLedger (Service)
Note: GeneXus provides an Hyperledger instance for concept proofing. Refer to section 'POC settings' for more information.
Go to GeneXus Menu > Build > Build Events
Set in the Post-build event command line:
msbuild "{GenexusPath}\gxnet\gxbuildcc.msbuild" /property:GX_TARGET_PATH="{TargetFullPath}";GX_PROGRAM_DIR={GenexusPath}
You may use these settings only for proof of concept purposes. Do not use it for any other purpose.
This instance is provided by http://powerledgers.com.
Server = "https://melisandre.ddns.net/api"
UserName= gxuser
UserPassword= domingo.menchaca.4096.fuxia
Chaincode prefix = <Autogenerated ID to uniquely identify your tests. If empty, put here a string that represents your company name + your name so that you can be contacted>
Chaincode postfix = <Autogenerated ID to uniquely identify your tests. If empty, put here a string to not mix different test cases>
Chaincode Case Sensitive = True
Take into account that Blockchain is a key/value storage
- It does not allow operations with Order clause
- It allows filters and conditions on its primary key only
- Only .NET Generator supports this feature