maya python textField + object name Assistance Please

Question

Here is my plan. First create a joint and open your node editor. When you got your joint created, name it "A_Joint" hit "load joint" after running the script, then hit "test" upon hitting test, you should get a node created with the name "A_Joint_firstGuy"

the objective of this script is to create a node based on the name of whatever you loaded into the textField. It will take the name of the selected object and add it to the front of the name of the node

Atleast thats what should happen, but in truth I lack the knowledge to figure this out and every google search has thus far been fruitless. The script is down below for anyone willing to take a crack at it, thank you for your time and I hope to hear back from you:

https://drive.google.com/file/d/1NvL0MZCDJcKAnVu6voVNYbaW0HurZ6Rh/view?usp=sharing

Or here, in SO format:

import maya.cmds as cmds

if cmds.window(window, exists =True):
    cmds.deleteUI(window)

window = cmds.window(title = "DS Selection Loader Demo", widthHeight=(300, 200) )
cmds.columnLayout(adjustableColumn=True) 

def sld_loadHelperJoint():
    sel = cmds.ls(selection=True)
    selString = " ".join(sel)
    add = cmds.textField('sld_surfaceTextHJ', edit=True, text=selString)

#def sld_loadParentJoint():
 #   sel = cmds.ls(selection=True)
  #  selString = " ".join(sel)
   # add = cmds.textField('sld_surfaceTextPJ', edit=True, text=selString)


def createNode():
    testNode = cmds.createNode( 'transform', selString = "sld_surfaceTextHJ", name = '_firstGuy' )



cmds.columnLayout(adjustableColumn=True)
sld_textFld = cmds.textField('sld_surfaceTextHJ', width =240)
cmds.button( label='Load Helper Joint', command = "sld_loadHelperJoint()")
cmds.setParent('..')

#cmds.columnLayout(adjustableColumn=True)
#name = cmds.textField('sld_surfaceTextPJ', width =240)
#cmds.button( label="Load Parent Joint", command = "sld_loadParentJoint()")
#cmds.setParent('..')

testNode = cmds.createNode( 'transform', name = textField +'_firstGuy' )


# you must first create "def" group for the attributes you 
# want to be created via button, "testNode" is our example

# Connect the translation of two nodes together
#cmds.connectAttr( 'firstGuy.t', 'secondGuy.translate' )

# Connect the rotation of one node to the override colour
# of a second node.
#cmds.connectAttr( 'firstGuy.rotate', 'secondGuy.overrideColor' )

cmds.showWindow (window)

Answer 1

OK, there's a few things going on here to consider.

First, Maya gui widgets look like strings -- just like you make a polyCube and it comes back to you as the string 'pCube1', a widget will come back as a string like 'myWindow' or 'textField72'. Just like working with scene objects, you always need to capture the results of a command so you know what it's really called -- you can't guarantee you'll get the name you asked for, so always capture the results.

So you want to do something like this, just to get the graphics going:

window = cmds.window(title='selection loader demo')
column = cmds.columnLayout(adj=True)
sld_textFld = cmds.textField('sld_surfaceTextHJ', width =240)
load_button = cmds.button( label='Load Helper Joint')
cmds.show_window(window)

If you needed to ask what's in the textField, for example, you'd do:

text_contents = cmds.textField(sld_textFld, q=True, text=True)

You notice that's with the variable, not the string, so we're sure we have whatever worked.

To make the button use that information, though, the button script needs to have access to the variable. There are several ways to do this -- it's a common stack overflow question -- but the easiest one is just to define the button command where you already have that variable. So the above sample becomes:

window = cmds.window(title='selection loader demo')
column = cmds.columnLayout(adj=True)
sld_textFld = cmds.textField('sld_surfaceTextHJ', width =240)

def set_textfield(_):
    sel = cmds.ls(selection=True)
    add = cmds.textField(sld_textFld, edit=True, text=sel[0])

load_button = cmds.button( label='Load Helper Joint', c = set_textfield)
cmds.showWindow(window)

There are two bits here.

One is the _ in the function definition; Maya buttons always call their functions with one argument. There's nothing magical about the underscore, it's just Python slang for "ignore me" -- but if you don't have an argument in the function def, it will fail.

The more important bit is that the button is given the function definition directly, without quotes. You are saying call this function when clicked. If you use the string version -- a holdover from MEL -- you will run into problems later. The reasons are explained in detail here but the TLDR is don't use the the string form. Ever.

Now that the structural pieces are in place, you should be able to either the node creation to the function I called set_textfield() or make a second button\function combo that does the actual node creation, something like:

window = cmds.window(title='selection loader demo')
column = cmds.columnLayout(adj=True)
sld_textFld = cmds.textField('sld_surfaceTextHJ', width =240)

def set_textfield(_):
    sel = cmds.ls(selection=True)
    cmds.textField(sld_textFld, edit=True, text=sel[0])

load_button = cmds.button( label='Load Helper Joint', c = set_textfield)

def make_node(_):
   text_value = cmds.textField(sld_textFld, q = True, text=True)
   if text_value:
       print "created:", cmds.createNode('transform', n=text_value +'_firstGuy')

   else:
       cmds.warning("select an object and add it to the window first!")

node_button = cmds.button( label='Make Node', c = make_node)

cmds.showWindow(window)