Add an image texture to a shader subgraph I am trying to create a material which uses a texture. That texture is used in a subgraph (I think the technical term in blender is NoedGroup, but Im not sure). The input for that subgraph is the texture name as a string, uv coordinates and some other stuff. 

I have a osl script which loads the texture using the texture name and do all the operations needed. The problem is that the script node is not compatible with eevee. 

Is there anyway to add the image texture as an input to the subgraph so I can replace the osl script with eevee compatible nodes?

I have check this other answer, but seems to be doing exactly what I currently have. 
Select Input Texture file name as parameter/node
Unfortunately there isn't any way to create a NodeGroup that has a Texture selection as an input without some coding to create Custom nodes. For the Custom node, you'd have to have the image texture node in the node tree, whose value you would change via code using the custom node UI. Please read information in the link below for a much more thorough explanation of this process.
Cycles Materials Math node with more than two inputs