Adding Input and Output parameters in C# code snippets

Replies to This Discussion

Permalink Reply by 0ddw589ypu3jv on February 16, 2017 at 1:47am

Hi,

You can do as follows:

    Grasshopper.Kernel.Parameters.Param_ScriptVariable param = new Grasshopper.Kernel.Parameters.Param_ScriptVariable();
    param.TypeHint = new Grasshopper.Kernel.Parameters.Hints.GH_BooleanHint_CS();
    param.NickName = "addparam";
    this.Component.Params.RegisterInputParam(param, this.Component.Params.Input.Count);

By the way,Param_ScriptVariable is only allowed for script components.

Panda.

Permalink Reply by David Rutten on February 16, 2017 at 3:48am

Yup, also always be sure to call Component.Params.OnParametersChanged() when you're done dicking with the parameters outside of normal channels.

Permalink Reply by Pirouz Nourian on February 16, 2017 at 5:12am

Hi David, 

The complete story is that I want to share user component objects only as their inner scripts on GitHub, for a relatively large group of students to collaborate. Long story short, the goal is to let a user bring a C# script component on GH canvas, paste the script from GitHub and then the right inputs should appear with descriptions and TypeHints. Currently it works with a hiccup:

Grasshopper.Kernel.Parameters.Param_ScriptVariable param0 = new Grasshopper.Kernel.Parameters.Param_ScriptVariable();
param0.Access = GH_ParamAccess.list;
param0.TypeHint = new Grasshopper.Kernel.Parameters.Hints.GH_CurveHint();
param0.NickName = "InC";
param0.Description = "Input curves to explode";
this.Component.Name = "GrevillePoints";
this.Component.NickName = "G_EditPoints";
if(!(this.Component.Params.Input.Exists(lambda => lambda.NickName == "InC")))
{
this.Component.Params.RegisterInputParam(param0, 0);
}
this.Component.Params.OnParametersChanged();
bool HasRunMoreThanOnce = (this.Component.RunCount > 0);
if(HasRunMoreThanOnce && this.Component.Params.Input.Exists(lambda => lambda.NickName == "InC"))
{
Point3dList[] CGVertices = new Point3dList[InC.Count];
for(int i = 0;i < InC.Count;i++)
{
Curve iCrv = InC[i];
NurbsCurve NC = iCrv.ToNurbsCurve();
CGVertices[i] = NC.GrevillePoints();
}
A = CGVertices;
}

The main part that actually requires the input curves cannot run because the component must be closed once so that the input gets actually added. At the moment, I can comment out that part, let it run once to create the input and then run the whole thing. Is there a way to postpone running the second part after the component has run at least once?

Any other way to set up a fully text-based collaboration workflow?

 

Permalink Reply by David Rutten on February 16, 2017 at 5:43am

Is sharing all that additional bookkeeping code really easier than sharing the components themselves?

The first problem you'll get is that you're not supposed to run code that modifies the topology of the graph (adding/removing wires, adding/removing inputs or outputs, changing parameter options like flatten/graft, enabling/disabling components, etc. etc.) within the solution.

The correct way to do it is to trigger that code from user interface events such as mouse clicks, or to handle the SolutionStart event on the relevant GH_Document and make the modifications there. This is difficult, maybe even impossible to do from a Script component because it doesn't get compiled until after the solution has started.

I assume you're looking for a solution within Rhino5? As in, there's nothing I can do to the Rhino6 wip that will help you short term?

Permalink Reply by Pirouz Nourian on February 16, 2017 at 7:44am

Sharing everything as scripts is most preferable because of its maximum readability for outsiders (e.g. those without GH installed). We'd like to streamline code reviews and tutorial writing, collecting best codes, etc. This would be all simplified by sharing textual code on GitHub. Of course there is always the option of sharing the GHA builder package as a Visual Studio project. However, this is not an option here because I'm working with a group of beginners. Besides, the ease of working with scripting components in terms of frequent editing would be gone with VS projects.

Let me describe it in another way: 

Component.Params.Input[0].NickName = "TextIN";
Component.Params.Input[0].Access = GH_ParamAccess.list;
Component.Params.Input[0].Description = "This is to test how to share..."

This works just fine; except for the fact that I could not fine a way to add a "TypeHint" because the Type property was read only. 

I understand why changing the topology of the components graph could be problematic. But cannot see the danger in changing the name and type hint of a parameter

Yes, it is about Rhino5, for the following 8 weeks so that we could exchange codes with students easily in both directions. 

Permalink Reply by Pirouz Nourian on February 16, 2017 at 4:10am

Hi Panda, 

Thanks a lot for this hint; however, after adding a parameter like this it is not possible to connect it to a data source (the magnet-like snapping on GH canvas does not allow wires to be connected to the registered/created parameter). Is something else needed to activate the registered input?

This is what I'm trying:

Grasshopper.Kernel.Parameters.Param_ScriptVariable param0 = new Grasshopper.Kernel.Parameters.Param_ScriptVariable();
param0.Access = GH_ParamAccess.list;
param0.TypeHint = new Grasshopper.Kernel.Parameters.Hints.GH_CurveHint();
param0.NickName = "InC";
param0.Description = "Input curves to explode";
//this.Component.Params.Input[0] = param0;//this way did not work either

this.Component.Params.RegisterInputParam(param0, 0);

Permalink Reply by 0ddw589ypu3jv on February 16, 2017 at 4:17am

Hi,

It works fine!

Permalink Reply by Pirouz Nourian on February 16, 2017 at 5:07am

Yes, but there is still a problem; has to be run twice to get it to work. I'll write above to David the whole story. Thanks very much for helping me out.