Support variadic parameters for .NET

[mpiroc]

This might be more involved that just adding the "params" keyword. Consider the following signature:

public void DoSomething(params object[] myParam)
{
}

// ...

object[] foo = // ...
// Because an object[] is also an object, the compiler treats foo as the first element
// of the params array, rather than the params array itself.
DoSomething(foo);

But in this case, there's no ambiguity:

public void DoSomething(params string[] myParam)
{
}

// ...

string[] foo = // ...

// The compiler treats foo as the params array, rather than the first element of the params array.
DoSomething(foo);

This might not matter, since generated code does not include any invocations of the generated methods. Just something to keep in mind.

[McDoit]

I guess i'm running into a related issue to this now in 0.29 of the C# CDK

AddActions of the PolicyStatement has the following signature
[JsiiMethod("addActions", "{\"type\":{\"fqn\":\"@aws-cdk/aws-iam.PolicyStatement\"}}", "[{\"name\":\"actions\",\"variadic\":true,\"type\":{\"primitive\":\"string\"}}]", false, false)]

But the generated C# method has the following signature, with a string
public virtual PolicyStatement AddActions(string actions)

Is there anyway i can create a correct string of a string params, or is this just something that need to be solved in this issue?

[bfeinb]

This has been an issue for a while. The way I deal with this situation is to create an extension method to get the behavior I want. For my purposes I wanted to add multiple actions via a comma delimited set of actions as a single string, but you could easily go with an IEnumerable<string> instead. The extension method I use is included below. It would be better to teach JSII how to deal with variable number of arguments in C#. Unfortunately I’m slammed on other projects at the moment, or I’d look at contributing something.

…

--Bonnie /// <summary> /// Adds actions to a policy statement from a comma separated list of actions names as part of initializing IAM objects. /// </summary> /// <param name="statement">What policy statement</param> /// <param name="actions">The names of the actions to add</param> /// <returns></returns> public static PolicyStatement AddActionsFromString(this PolicyStatement statement, string actions) { var policyStatement = statement; foreach (string action in actions.Split(", ")) { policyStatement = policyStatement.AddAction(action); } return policyStatement; } From: Erik Karlsson <notifications@github.com> Sent: Thursday, April 25, 2019 6:15 AM To: awslabs/jsii <jsii@noreply.github.com> Cc: Feinberg, Bonnie <feinbb@amazon.com>; Manual <manual@noreply.github.com> Subject: Re: [awslabs/jsii] Support variadic parameters for .NET (#153) I guess i'm running into a related issue to this now in 0.29 of the C# CDK AddActions of the PolicyStatement has the following signature [JsiiMethod("addActions", "{\"type\":{\"fqn\":\"@aws-cdk/aws-iam.PolicyStatement\"}}", "[{\"name\":\"actions\",\"variadic\":true,\"type\":{\"primitive\":\"string\"}}]", false, false)] But the generated C# method has the following signature, with a string public virtual PolicyStatement AddActions(string actions) Is there anyway i can create a correct string of a string params, or is this just something that need to be solved in this issue? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub<#153 (comment)>, or mute the thread<https://github.com/notifications/unsubscribe-auth/AKCL62L6TAIWZTQYUNEVUXTPSGVGDANCNFSM4FOENHGQ>.

[McDoit]

This has been an issue for a while. The way I deal with this situation is to create an extension method to get the behavior I want. For my purposes I wanted to add multiple actions via a comma delimited set of actions as a single string, but you could easily go with an IEnumerable instead. The extension method I use is included below. It would be better to teach JSII how to deal with variable number of arguments in C#. Unfortunately I’m slammed on other projects at the moment, or I’d look at contributing something.
…
--Bonnie ///

/// Adds actions to a policy statement from a comma separated list of actions names as part of initializing IAM objects. ///

/// What policy statement /// The names of the actions to add /// public static PolicyStatement AddActionsFromString(this PolicyStatement statement, string actions) { var policyStatement = statement; foreach (string action in actions.Split(", ")) { policyStatement = policyStatement.AddAction(action); } return policyStatement; } From: Erik Karlsson notifications@github.com Sent: Thursday, April 25, 2019 6:15 AM To: awslabs/jsii jsii@noreply.github.com Cc: Feinberg, Bonnie feinbb@amazon.com; Manual manual@noreply.github.com Subject: Re: [awslabs/jsii] Support variadic parameters for .NET (#153) I guess i'm running into a related issue to this now in 0.29 of the C# CDK AddActions of the PolicyStatement has the following signature [JsiiMethod("addActions", "{"type":{"fqn":"@aws-cdk/aws-iam.PolicyStatement"}}", "[{"name":"actions","variadic":true,"type":{"primitive":"string"}}]", false, false)] But the generated C# method has the following signature, with a string public virtual PolicyStatement AddActions(string actions) Is there anyway i can create a correct string of a string params, or is this just something that need to be solved in this issue? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub<#153 (comment)>, or mute the threadhttps://github.com/notifications/unsubscribe-auth/AKCL62L6TAIWZTQYUNEVUXTPSGVGDANCNFSM4FOENHGQ.

Thank you @bfeinb

I tried something similar with a static method and looping over several actions, but then i get the following error in the app.Run() step:

Amazon.JSII.Runtime.JsiiException: 'While synthesizing mimer-ses-15/db-key/Resource: System.ArgumentException: Could not convert value 'System.Collections.Generic.Dictionary`2[System.String,System.Object]' with unrecognized type
Parameter name: value

Only reason i need it is beacuase of a related issue in the new 0.29, aws/aws-cdk#2375
I guess i will have to wait for that, or just create a new statement for every action instead