LEARN HOLONET/Tutorials
TutorialHoloNET 4.x · Holochain 0.7.0 / 0.7.1

Save data in one line

You'll build: an app that saves, loads and deletes settings and objects on Holochain, with no Rust, no zome calls and no setup code. Time: 10 minutes. You need: a running conductor (see Your first zome call, step 1). Finished code: examples/03-API.

1. Create the project

bash
dotnet new console -n OneLiners
cd OneLiners
dotnet add package NextGenSoftware.Holochain.HoloNET.API

HoloNET API brings the OASIS hApp with it, and installs it on first use.

2. Point it at your conductor

csharp
using NextGenSoftware.Holochain.HoloNET.API;

HoloNETAPI.UseConductor("ws://localhost:7777", logToConsole: false);

With an .Embedded Client package you'd skip this, and the API would start its own conductor.

3. One line each

csharp
await HoloNETAPI.SaveDataAsync("theme", "dark");
string theme = (await HoloNETAPI.LoadDataAsync("theme")).Result;          // "dark"

await HoloNETAPI.SaveDataAsync("score", 9001);                             // any type
int score = (await HoloNETAPI.LoadDataAsync<int>("score")).Result;         // back as an int

await HoloNETAPI.SaveObjectAsync("player", new Player { Name = "Ada", Level = 3 });
Player p = (await HoloNETAPI.LoadObjectAsync<Player>("player")).Result;

var keys = (await HoloNETAPI.ListKeysAsync()).Result;                      // theme, score
await HoloNETAPI.DeleteDataAsync("theme");

public class Player { public string Name { get; set; } public int Level { get; set; } }

Run it twice. The second time, LoadDataAsync("score") returns 9001 straight away, because the data is on Holochain, not in memory.

4. Check results, not exceptions

Every call returns IsSuccess, Result and Message, and nothing throws:

csharp
var missing = await HoloNETAPI.LoadDataAsync("nope");
if (!missing.IsSuccess) Console.WriteLine(missing.Message);   // "No data has been saved under the key 'nope'."

5. No async? No problem

Unity scripts and simple console apps can use the sync versions:

csharp
HoloNETAPI.SaveData("volume", "7");
string volume = HoloNETAPI.LoadData("volume").Result;

What just happened

  • Connecting. On the first call, the API connected, installed the bundled OASIS hApp, and remembered it in HoloNETAPIDNA.json.
  • Storage. Each key is its own entry on Holochain, so saving one key stays fast however many you have.
  • Privacy. Your store belongs to your agent. To share data with everyone, use shared data.

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