Durable orchestrations

const df = require("durable-functions");

df.app.orchestration("helloSequence", function* (context) {
    const output = [];
    output.push(yield context.df.callActivity("sayHello", "Tokyo"));
    output.push(yield context.df.callActivity("sayHello", "Seattle"));
    output.push(yield context.df.callActivity("sayHello", "London"));

    // Return ["Hello Tokyo!", "Hello Seattle!", "Hello London!"].
    return output;
});

import azure.functions as func
import azure.durable_functions as df

app = df.DFApp(http_auth_level=func.AuthLevel.ANONYMOUS)

@app.orchestration_trigger(context_name="context")
def orchestrator_function(context: df.DurableOrchestrationContext):
    result1 = yield context.call_activity('SayHello', "Tokyo")
    result2 = yield context.call_activity('SayHello', "Seattle")
    result3 = yield context.call_activity('SayHello', "London")
    return [result1, result2, result3]

param($Context)

$output = @()

$output += Invoke-DurableActivity -FunctionName 'SayHello' -Input 'Tokyo'
$output += Invoke-DurableActivity -FunctionName 'SayHello' -Input 'Seattle'
$output += Invoke-DurableActivity -FunctionName 'SayHello' -Input 'London'

$output

@FunctionName("HelloCities")
public String helloCitiesOrchestrator(
        @DurableOrchestrationTrigger(name = "ctx") TaskOrchestrationContext ctx) {
    String result = "";
    result += ctx.callActivity("SayHello", "Tokyo", String.class).await() + ", ";
    result += ctx.callActivity("SayHello", "Seattle", String.class).await() + ", ";
    result += ctx.callActivity("SayHello", "London", String.class).await();
    return result;
}

using Microsoft.DurableTask;

[DurableTask]
public class HelloCities : TaskOrchestrator<object?, List<string>>
{
    public override async Task<List<string>> RunAsync(TaskOrchestrationContext context, object? input)
    {
        var outputs = new List<string>();

        outputs.Add(await context.CallActivityAsync<string>("SayHello", "Tokyo"));
        outputs.Add(await context.CallActivityAsync<string>("SayHello", "Seattle"));
        outputs.Add(await context.CallActivityAsync<string>("SayHello", "London"));

        return outputs;
    }
}

This sample is shown for .NET, Java, and Python.

from durabletask import task

def hello_cities(ctx: task.OrchestrationContext, _):
    result1 = yield ctx.call_activity("say_hello", input="Tokyo")
    result2 = yield ctx.call_activity("say_hello", input="Seattle")
    result3 = yield ctx.call_activity("say_hello", input="London")
    return [result1, result2, result3]

This sample is shown for .NET, Java, and Python.

import com.microsoft.durabletask.TaskOrchestration;
import com.microsoft.durabletask.TaskOrchestrationContext;

public class HelloCities implements TaskOrchestration {
    @Override
    public void run(TaskOrchestrationContext ctx) {
        String result = "";
        result += ctx.callActivity("SayHello", "Tokyo", String.class).await() + ", ";
        result += ctx.callActivity("SayHello", "Seattle", String.class).await() + ", ";
        result += ctx.callActivity("SayHello", "London", String.class).await();
        ctx.complete(result);
    }
}

const df = require("durable-functions");

df.app.orchestration("checkSiteAvailable", function* (context) {
    const url = context.df.getInput();
    var res = yield context.df.callHttp({ method: "GET", url });
    if (res.statusCode >= 400) {
        // Handle error codes.
    }
});

import azure.functions as func
import azure.durable_functions as df

app = df.DFApp(http_auth_level=func.AuthLevel.ANONYMOUS)

@app.orchestration_trigger(context_name="context")
def orchestrator_function(context: df.DurableOrchestrationContext):
    url = context.get_input()
    res = yield context.call_http('GET', url)
    if res['statusCode'] >= 400:
        # Handle error codes.

The feature isn't currently supported in PowerShell.

The feature isn't currently supported in Java.

const df = require("durable-functions");

df.app.orchestration("getWeatherOrchestrator", function* (context) {
    const location = {
        city: "Seattle",
        state: "WA",
    };
    const weather = yield context.df.callActivity("getWeather", location);

    // ...
});

df.app.activity("getWeather", {
    handler: async (input) => {
        const { city, state } = input; // Destructure properties into variables.
        // ...
    }
});

from collections import namedtuple
import azure.functions as func
import azure.durable_functions as df

app = df.DFApp(http_auth_level=func.AuthLevel.ANONYMOUS)

@app.orchestration_trigger(context_name="context")
def orchestrator_function(context: df.DurableOrchestrationContext):
    Location = namedtuple('Location', ['city', 'state'])
    location = Location(city='Seattle', state='WA')

    weather = yield context.call_activity("GetWeather", location)
    # ...

@app.activity_trigger(input_name="location")
def GetWeather(location):
    city, state = location
    return f"Hello {city}, {state}!"

param($Context)

$location = @{
    City = 'Seattle'
    State  = 'WA'
}

Invoke-ActivityFunction -FunctionName 'GetWeather' -Input $location

# ...

@FunctionName("GetWeatherOrchestrator")
public String getWeatherOrchestrator(
        @DurableOrchestrationTrigger(name = "ctx") TaskOrchestrationContext ctx) {
    var location = new Location();
    location.city = "Seattle";
    location.state = "WA";
    String weather = ctx.callActivity("GetWeather", location, String.class).await();
    return weather;
}

In .NET, you can use record types or tuples to pass multiple parameters as a single composite object.

using Microsoft.DurableTask;

public record LocationInfo(string City, string State);

[DurableTask]
public class GetWeatherOrchestration : TaskOrchestrator<object?, string>
{
    public override async Task<string> RunAsync(TaskOrchestrationContext context, object? input)
    {
        var location = new LocationInfo("Seattle", "WA");
        string weather = await context.CallActivityAsync<string>("GetWeather", location);
        return weather;
    }
}

This sample is shown for .NET, Java, and Python.

from durabletask import task

def get_weather_orchestrator(ctx: task.OrchestrationContext, _):
    location = {"city": "Seattle", "state": "WA"}
    weather = yield ctx.call_activity("get_weather", input=location)
    # ...

This sample is shown for .NET, Java, and Python.

import com.microsoft.durabletask.TaskOrchestration;
import com.microsoft.durabletask.TaskOrchestrationContext;

public class GetWeatherOrchestration implements TaskOrchestration {
    @Override
    public void run(TaskOrchestrationContext ctx) {
        Location location = new Location();
        location.city = "Seattle";
        location.state = "WA";
        String weather = ctx.callActivity("GetWeather", location, String.class).await();
        ctx.complete(weather);
    }
}