karthik25/taskable

Read Me

Taskable is an attempt to do complex tasks with english like statements. Taskable can be used as scriptcs script pack or a WPF application. For example, you will be able to do the following -

git-download https://github.com/karthik25/sblog.net/archive/master.zip to d:\temp\GitDownloads

In order to download an copy a file in to a specified location!

Taskable was highly influenced by bau. I was using Bau for a few things and something I missed the most was the ability to pass parameters. I did submit a PR for it. But it still hasn't been merged, prompting me to think of something else and I thought of this - taskable! At that point I had rarely used powershell and when I did, I was surprsied to see how similar my thought process was to powershell!That's one reason I would say taskable is the Poor man's PowerShell :-)

Script Pack (scriptcs package)

This section currently deals with the taskable script pack built locally. Before going any further, you need to install chocolatey and then scriptcs. First step is to create the nupkg that contains script pack. To create the nuget package, navigate to the TaskableScriptPack project's directory. The .nuspec file is already present in here. Enter the following to create the package:

nuget pack TaskableScriptPack.csproj -IncludeReferencedProjects

Once this is done a .nupkg file is created. Copy this to a directory of your choice. Then, you need to inform nuget about the presence of this package. To do this go to %AppData%\NuGet\NuGet.config and add a new key to the packageSources element to indicate the location of this package. Refere to this link for more information about how scriptcs locates packages.

Next step is to add an entry for Taskable in your scriptcs_packages.config.

<package id="TaskableScriptPack" version="1.0.0" targetFramework="net46" />

After this step, you are ready to install the package and you can do this by running:

scriptcs -install

in your scriptcs home.

Here is the simplest taskable task for your perusal, lets call it hello_taskable.csx!

var taskable = Require<Taskable>();

[TaskName("Echo Task")]
[TaskExample("echo hello")]
[TaskExample(@"echo ""hello again""")]
public class EchoTask : ISimpleTask
{
    public string Pattern
    {
        get
        {
            return "echo {}";
        }
    }

    public Action<string[]> Stuff
    {
        get
        {
            return parameters =>
            {
                Console.WriteLine($"Echo: {parameters[0]}");
            };
        }
    }
}

taskable.RegisterTask(new EchoTask());
taskable.WaitForCommands();

As you can see, your task needs to implement the ISimpleTask interface which has a property called Pattern and an action called Stuff. Pattern defines a task's name and its parameters. For example, in this case itsecho {}, where echo is the task name and {} indicates that this task takes 1 parameter which is passed on to the action method!

Here is yet another task. This task downloads the identified file that is available to the public. Also, notice line 98. You have a Bind method that can be used to, as the name suggests, bind the parameters array to a strongly typed object.

using System.Net;

var taskable = Require<Taskable>();

[TaskName("Download Task")]
[TaskExample(@"git-download https://github.com/karthik25/sblog.net/archive/master.zip to d:\temp\GitDownloads")]
public class GitDownloadTask : ISimpleTask
{
    public string Pattern
    {
        get
        {
            return "git-download {} to {}";
        }
    }

    public Action<string[]> Stuff
    {
        get
        {
            return parameters =>
            {
                var options = parameters.Bind<DownloadOptions>();
                var destinationFileName = Path.GetFileName(options.FileUrl);
                Console.WriteLine($"Copying {options.FileUrl} to {options.DestinationDirectory}");
                try{
                    WebClient client = new WebClient();
                    client.DownloadFile(options.FileUrl, $@"{options.DestinationDirectory}\{destinationFileName}");
                }
                catch(Exception ex){
                    Console.WriteLine(ex.ToString());
                }
            };
        }
    }
}

taskable.RegisterTask(new GitDownloadTask());
taskable.WaitForCommands();

DownloadOptions is a simple POCO, where the properties are decorated with a special attribute called ParameterIndex which identifies the position of this property in the parameters string array passed to the action method!

public class DownloadOptions
{
    [ParameterIndex(0)]
    public string FileUrl { get;set; }
    [ParameterIndex(1)]
    public string DestinationDirectory { get; set; }
}

To start using taskable, you can do the following:

> scriptcs hello_taskable.csx

Now you can start calling the registered commands! For example, the following would run the echo task and display the results.

> echo hello