BindingName

BindingNameConfiguration

BlobInput

BlobConfiguration

BlobOutput

BlobTrigger

@azurefunctions:CosmosDBInput annotation.


CosmosDBInput

CosmosDBInputConfiguration

@azurefunctions:CosmosDBOutput annotation.


CosmosDBOutput

CosmosDBOutputConfiguration

@azurefunctions:CosmosDBTrigger annotation.


CosmosDBTrigger

CosmosDBTriggerConfiguration

Function

HTTPOutput

HTTPTrigger

HTTPTriggerConfiguration

QueueOutput

QueueConfiguration

QueueTrigger

@azurefunctions:TimerTrigger annotation.


TimerTrigger

TimerTriggerConfiguration

@azurefunctions:TwilioSmsOutput annotation.


TwilioSmsOutput

TwilioSmsConfiguration

metadata

json

init

hparams

HandlerParams

populateMetadata

boolean

error

string

Context

## Overview

This module provides an annotation-based [Azure Functions](https://azure.microsoft.com/en-us/services/functions/) extension implementation for Ballerina. 
 

## Supported Annotations:

### @azure.functions:Function

#### Custom 'host.json'

A custom [host.json](https://docs.microsoft.com/en-us/azure/azure-functions/functions-host-json) file for the functions deployment can be optionally provided by placing a 'host.json' file in the current working directory where the bal build is done. The required host.json properties are provided/overridden by the values derived from the source code by the compiler extension. 

#### Usage Sample:

```ballerina
import ballerina/uuid;
import ballerinax/azure_functions as af;

// HTTP request/response with no authentication
@af:Function
public function hello(@af:HTTPTrigger { authLevel: "anonymous" } string payload) 
                      returns @af:HTTPOutput string|error {
    return "Hello, " + payload + "!";
}

// HTTP request to add data to a queue
@af:Function
public function fromHttpToQueue(af:Context ctx, 
            @af:HTTPTrigger {} af:HTTPRequest req, 
            @af:QueueOutput { queueName: "queue1" } af:StringOutputBinding msg) 
            returns @af:HTTPOutput af:HTTPBinding {
    msg.value = req.body;
    return { statusCode: 200, payload: "Request: " + req.toString() };
}

// A message put to a queue is copied to another queue
@af:Function
public function fromQueueToQueue(af:Context ctx, 
        @af:QueueTrigger { queueName: "queue2" } string inMsg,
        @af:QueueOutput { queueName: "queue3" } af:StringOutputBinding outMsg) {
    ctx.log("In Message: " + inMsg);
    ctx.log("Metadata: " + ctx.metadata.toString());
    outMsg.value = inMsg;
}

// A blob added to a container is copied to a queue
@af:Function
public function fromBlobToQueue(af:Context ctx, 
        @af:BlobTrigger { path: "bpath1/{name}" } byte[] blobIn,
        @af:BindingName { } string name,
        @af:QueueOutput { queueName: "queue3" } af:StringOutputBinding outMsg) 
        returns error? {
    outMsg.value = "Name: " + name + " Content: " + blobIn.toString();
}

// HTTP request to read a blob value
@af:Function
public function httpTriggerBlobInput(@af:HTTPTrigger { } af:HTTPRequest req, 
                    @af:BlobInput { path: "bpath1/{Query.name}" } byte[]? blobIn)
                    returns @af:HTTPOutput string {
    int length = 0;
    if blobIn is byte[] {
        length = blobIn.length();
    }
    return "Blob: " + req.query["name"].toString() + " Length: " + 
            length.toString() + " Content: " + blobIn.toString();
}

// HTTP request to add a new blob
@af:Function
public function httpTriggerBlobOutput(@af:HTTPTrigger { } af:HTTPRequest req, 
        @af:BlobOutput { path: "bpath1/{Query.name}" } af:StringOutputBinding bb)
        returns @af:HTTPOutput string|error {
    bb.value = req.body;
    return "Blob: " + req.query["name"].toString() + " Content: " + 
            bb?.value.toString();
}

// Sending an SMS
@af:Function
public function sendSMS(@af:HTTPTrigger { } af:HTTPRequest req, 
                        @af:TwilioSmsOutput { fromNumber: "+12069845840" } 
                                              af:TwilioSmsOutputBinding tb)
                        returns @af:HTTPOutput string {
    tb.to = req.query["to"].toString();
    tb.body = req.body.toString();
    return "Message - to: " + tb?.to.toString() + " body: " + tb?.body.toString();
}

public type Person record {
    string id;
    string name;
    string country;
};

// CosmosDB record trigger
@af:Function
public function cosmosDBToQueue1(@af:CosmosDBTrigger { 
        connectionStringSetting: "CosmosDBConnection", databaseName: "db1",
        collectionName: "c1" } Person[] req, 
        @af:QueueOutput { queueName: "queue3" } af:StringOutputBinding outMsg) {
    outMsg.value = req.toString();
}

@af:Function
public function cosmosDBToQueue2(@af:CosmosDBTrigger { 
        connectionStringSetting: "CosmosDBConnection", databaseName: "db1", 
        collectionName: "c2" } json req,
        @af:QueueOutput { queueName: "queue3" } af:StringOutputBinding outMsg) {
    outMsg.value = req.toString();
}

// HTTP request to read CosmosDB records
@af:Function
public function httpTriggerCosmosDBInput1(
            @af:HTTPTrigger { } af:HTTPRequest httpReq, 
            @af:CosmosDBInput { connectionStringSetting: "CosmosDBConnection", 
                databaseName: "db1", collectionName: "c1", 
                id: "{Query.id}", partitionKey: "{Query.country}" } json dbReq)
                returns @af:HTTPOutput string|error {
    return dbReq.toString();
}

@af:Function
public function httpTriggerCosmosDBInput2(
            @af:HTTPTrigger { } af:HTTPRequest httpReq, 
            @af:CosmosDBInput { connectionStringSetting: "CosmosDBConnection", 
                databaseName: "db1", collectionName: "c1", 
                id: "{Query.id}", partitionKey: "{Query.country}" } Person? dbReq)
                returns @af:HTTPOutput string|error {
    return dbReq.toString();
}

@af:Function
public function httpTriggerCosmosDBInput3(
        @af:HTTPTrigger { route: "c1/{country}" } af:HTTPRequest httpReq, 
        @af:CosmosDBInput { connectionStringSetting: "CosmosDBConnection", 
        databaseName: "db1", collectionName: "c1", 
        sqlQuery: "select * from c1 where c1.country = {country}" } 
        Person[] dbReq)
        returns @af:HTTPOutput string|error {
    return dbReq.toString();
}

// HTTP request to write records to CosmosDB
@af:Function
public function httpTriggerCosmosDBOutput1(
    @af:HTTPTrigger { } af:HTTPRequest httpReq, @af:HTTPOutput af:HTTPBinding hb) 
    returns @af:CosmosDBOutput { connectionStringSetting: "CosmosDBConnection", 
                                 databaseName: "db1", collectionName: "c1" } json {
    json entry = { id: uuid:createType1AsString(), name: "Saman", country: "Sri Lanka" };
    hb.payload = "Adding entry: " + entry.toString();
    return entry;
}

@af:Function
public function httpTriggerCosmosDBOutput2(
        @af:HTTPTrigger { } af:HTTPRequest httpReq, 
        @af:HTTPOutput af:HTTPBinding hb) 
        returns @af:CosmosDBOutput { 
            connectionStringSetting: "CosmosDBConnection", 
            databaseName: "db1", collectionName: "c1" } json {
    json entry = [{ id: uuid:createType1AsString(), name: "John Doe A", country: "USA" }, 
                  { id: uuid:createType1AsString(), name: "John Doe B", country: "USA" }];
    hb.payload = "Adding entries: " + entry.toString();
    return entry;
}

@af:Function
public function httpTriggerCosmosDBOutput3(
                    @af:HTTPTrigger { } af:HTTPRequest httpReq) 
                    returns @af:CosmosDBOutput { 
                        connectionStringSetting: "CosmosDBConnection", 
                        databaseName: "db1", collectionName: "c1" } Person[] {
    Person[] persons = [];
    persons.push({id: uuid:createType1AsString(), name: "Jack", country: "UK"});
    persons.push({id: uuid:createType1AsString(), name: "Will", country: "UK"});
    return persons;
}

// A timer function which is executed every 10 seconds.
@af:Function
public function queuePopulationTimer(
            @af:TimerTrigger { schedule: "*/10 * * * * *" } json triggerInfo, 
            @af:QueueOutput { queueName: "queue4" } af:StringOutputBinding msg) {
    msg.value = triggerInfo.toString();
}
```

The output of the bal build is as follows:

```bash
$ bal build azure_functions_deployment.bal 
Compiling source
        azure_functions_deployment.bal

Generating executables
        azure_functions_deployment.jar
        @azure.functions:Function: hello, fromHttpToQueue, fromQueueToQueue, fromBlobToQueue, httpTriggerBlobInput, httpTriggerBlobOutput, sendSMS, cosmosDBToQueue1, cosmosDBToQueue2, httpTriggerCosmosDBInput1, httpTriggerCosmosDBInput2, httpTriggerCosmosDBInput3, httpTriggerCosmosDBOutput1, httpTriggerCosmosDBOutput2, httpTriggerCosmosDBOutput3, queuePopulationTimer
```


INTERNAL usage - registers a handler function.



__register

name

funcHandler

FunctionHandler

INTERNAL usage - creates function context.



createContext

INTERNAL usage - Returns a converted Ballerina value from input data.



getBallerinaValueFromInputData

params

recordType

anydata

INTERNAL usage - Returns the binary payload from the HTTP request.



getBinaryFromHTTPReq

INTERNAL usage - Returns the HTTP body value from input data.



getBodyFromHTTPInputData

INTERNAL usage - Returns the binary value from input data.



getBytesFromInputData

INTERNAL usage - Populates the HTTP request structure from an input data entry.



getHTTPRequestFromInputData

HTTPRequest

INTERNAL usage - Returns the HTTP request data.



getHTTPRequestFromParams

Request

INTERNAL usage - Returns the JSON payload from the HTTP request.



getJsonFromHTTPReq

INTERNAL usage - Returns the JSON value from input data.



getJsonFromInputData

INTERNAL usage - Returns a json value from metadata.



getJsonFromMetadata

INTERNAL usage - Returns the JSON string value from input data.



getJsonStringFromInputData

INTERNAL usage - extracts the metadata.



getMetadata

INTERNAL usage - Returns the optional converted Ballerina value from "getParsedJsonFromJsonStringFromInputData".



getOptionalBallerinaValueFromInputData

INTERNAL usage - Returns the optional binary value from input data.



getOptionalBytesFromInputData

INTERNAL usage - Returns the optional string value converted from input binary data.



getOptionalStringConvertedBytesFromInputData

INTERNAL usage - Returns the optional string value from input data.



getOptionalStringFromInputData

INTERNAL usage - JSON parse the string value available from "getJsonStringFromInputData".



getParsedJsonFromJsonStringFromInputData

INTERNAL usage - Returns the string value converted from input binary data.



getStringConvertedBytesFromInputData

INTERNAL usage - Returns the string payload from the HTTP request.



getStringFromHTTPReq

INTERNAL usage - Returns the string value from input data.



getStringFromInputData

INTERNAL usage - Returns a string value from metadata.



getStringFromMetadata

INTERNAL usage - Converts a Ballerina value to a JSON and set the return value.



setBallerinaValueAsJsonReturn

value

setBlobOutput

binding

INTERNAL usage - Converts a CosmosDS Ballerina value to a JSON and set the return value.



setCosmosDBBallerinaValueAsJsonReturn

partitionKey

INTERNAL usage - Sets the CosmosDS JSON return value.



setCosmosDBJsonReturn

setHTTPOutput

HTTPBinding

INTERNAL usage - Sets the HTTP binding return value.



setHTTPReturn

INTERNAL usage - Sets the JSON return value.



setJsonReturn

INTERNAL usage - Sets the pure HTTP output.



setPureHTTPOutput

INTERNAL usage - Sets the pure string output.



setPureStringOutput

INTERNAL usage - Sets the string output.



setStringOutput

StringOutputBinding

INTERNAL usage - Sets the string return value.



setStringReturn

INTERNAL usage - Sets the Twilio output.



setTwilioSmsOutput

TwilioSmsOutputBinding

path

The name of the app setting which contains the Storage connection string


connection

byte

BytesOutputBinding

CosmosDB input annotation configuration.



The name of the app setting which contains the connection string for CosmosDB account


connectionStringSetting

databaseName

collectionName

An Azure Cosmos DB SQL query used to retrieve multiple documents


sqlQuery

float

A comma-seperated list of regions as preferred locations for geo-replicated database accounts


preferredLocations

CosmosDB output annotation configuration.



Creates the collection is it does not exist


createIfNotExists

The throughput of a newly created collection


collectionThroughput

useMultipleWriteLocations

CosmosDB trigger annotation configuration.



The name of the app setting which contains the lease connection string


leaseConnectionStringSetting

leaseDatabaseName

The name of the collection used to store leases


leaseCollectionName

The lease collection is automatically created when this is set to true


createLeaseCollectionIfNotExists

The request throughput of the lease collection


leasesCollectionThroughput

leaseCollectionPrefix

The time delay (in milliseconds) in polling a partition for new changes in the feed


feedPollDelay

The time (in milliseconds) the interval to create a task to check if partitions are distributed evenly


leaseAcquireInterval

The lease expiration interval in milliseconds


leaseExpirationInterval

The lease renewal interval in milliseconds


leaseRenewInterval

The interval (in milliseconds) between lease checkpoints


checkpointFrequency

The maximum number of items received per function call


maxItemsPerInvocation

Tells the trigger to read changes from the beginning of the collection's change history


startFromBeginning

INTERNAL stucture - the request handler parameter data.



request

response

Response

The flag to mention if it's a pure HTTP request


pure

result

statusCode

payload

method

query

headers

identities

body

The authentication level of the function


authLevel

AUTH_LEVEL

route

queueName

The CRON expression representing the timer schedule.


schedule

The flag to state if the timer should be started on a runtime restart


runOnStartup

The app setting which holds the Twilio Account Sid


accountSidSetting

The app setting which holds the Twilio authentication token


authTokenSetting

fromNumber

This module provides an annotation-based [Azure Functions](https://azure.microsoft.com/en-us/services/functions/) extension implementation for Ballerina. 


Record: StringOutputBinding

Fields