GH_Component.Message Property Implementation

I am trying to implement a custom message using the GH_Component.Message Property (which should appear similar to the one seen in the attached image) in visual studio in c# but I am having difficulty figuring out where the code should be executed.

The issue is that when I first drop the component on the canvas, the message does not show up until I fiddle with some inputs, but I want a default message to appear as soon as the component is placed on the canvas.

Replies to This Discussion

Permalink Reply by Andrew Heumann on January 16, 2015 at 12:43pm

My typical approach is to call the message updater in the class constructor, like so:

private bool some_property;

//my class constructor

My_ComponentClass() : base(blah blah blah){

some_property = true; //the default value for the component;

updateMessage();

}

//message updater

private void updateMessage()
        {
            if (some_property)
            {
                Message = "Property is True!";
            }
            else
            {
                Message = "Property is not true.";
            }
        }

also note that if you want the variable message property to persist through copy-paste / save / reopen, you'll need to override Read and Write functions:

public override bool Write(GH_IWriter writer)
        {
            writer.SetBoolean("SomeProperty", someProperty);
            return base.Write(writer);
        }
        public override bool Read(GH_IReader reader)
        {
            someProperty = false;
            reader.TryGetBoolean("SomeProperty", ref someProperty);
updateMessage();
            return base.Read(reader);
        }

Permalink Reply by Scott Overall on January 19, 2015 at 2:37am

Thanks, this worked as advertised. What I was missing was setting the message in the class constructor and then re-setting it in the read function. Examples like this are really useful for understanding how this all works.

The only small thing missing in your example is declaring the some_property variable outside of the class constructor (for anyone looking to copy this example code in the future).

Permalink Reply by David Stasiuk on July 2, 2015 at 10:03am