ShaderGraphAssetImporter.cs

using System;
using System.IO;
using System.Text;
using UnityEditor.AssetImporters;
using UnityEditor.ShaderGraph.GraphUI;
using UnityEngine;

namespace UnityEditor.ShaderGraph
{
    [ExcludeFromPreset]
    [ScriptedImporter(1, Extension, -902)]
    class ShaderGraphAssetImpoter : ScriptedImporter
    {
        public const string Extension = ShaderGraphStencil.GraphExtension;

        public const string k_ErrorShader = @"
Shader ""Hidden/GraphErrorShader2""
{
    SubShader
    {
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma target 2.0
            #pragma multi_compile _ UNITY_SINGLE_PASS_STEREO STEREO_INSTANCING_ON STEREO_MULTIVIEW_ON
            #include ""UnityCG.cginc""

            struct appdata_t {
                float4 vertex : POSITION;
                UNITY_VERTEX_INPUT_INSTANCE_ID
            };

            struct v2f {
                float4 vertex : SV_POSITION;
                UNITY_VERTEX_OUTPUT_STEREO
            };

            v2f vert (appdata_t v)
            {
                v2f o;
                UNITY_SETUP_INSTANCE_ID(v);
                UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
                o.vertex = UnityObjectToClipPos(v.vertex);
                return o;
            }
            fixed4 frag (v2f i) : SV_Target
            {
                return fixed4(1,0,1,1);
            }
            ENDCG
        }
    }
    Fallback Off
}";

        static string[] GatherDependenciesFromSourceFile(string assetPath)
        {
            if (string.CompareOrdinal(Path.GetExtension(assetPath), "."+Extension) == 0)
            {
                return ShaderGraphAssetUtils.GatherDependenciesForShaderGraphAsset(assetPath);
            }
            return new string[0];
        }

        public override void OnImportAsset(AssetImportContext ctx)
        {
            if (string.CompareOrdinal(Path.GetExtension(assetPath), "."+Extension) == 0)
            {
                ShaderGraphAssetUtils.HandleImportAssetGraph(ctx);
            }
        }
    }
}