updated virtual environment documentation

Author: Cerem Cem ASLAN

Makefile

@@ -6,6 +6,7 @@ CONFIG := $(DIR)../dcs-modules.txt
 .PHONY: test-es6-compat update-deps update-app-version
 
 # Check if we are in a VIRTUAL_ENV:
+# the `NODE_VIRTUAL_ENV` variable is set by nodeenv after activating the environment.
 __c:
 	$(if $(NODE_VIRTUAL_ENV),,$($(warning ************  WARNING: NOT INSIDE A VIRTUAL ENV  ************)))
 

doc/using-virtual-environment.md

@@ -25,37 +25,30 @@
 
 4. Install the Scada.js dependencies:
 
+        $ ./venv
         (scadajs1) $ make install-deps CONF=../dcs-modules.txt
         
-5. Optional: Move your nodeenv to a central location and use it between projects:
-        
-        dest=$HOME/nodeenv/scadajs-1  # or anywhere you like
-        mv nodeenv/ $dest  
-        echo "export SCADAJS_1_ENV='$dest'" >> ~/.bashrc
+# Using virtual environment from within Tmux
 
-   > Next time you can use: `./scada.js/venv`
+1. (Optional) Set the `SCADAJS_VENV_PATH` variable for the `TARGET_TMUX_SESSION`:
 
-# Preparing Tmux
+```bash
+tmux setenv -t ${TARGET_TMUX_SESSION} 'SCADAJS_VENV_PATH' /path/to/somewhere/scadajs1
+```
 
-1. Add the following in your `~/.profile` (or `~/.bashrc`):
+2. On every new pane, manually activate your virtual environment by:
 
 ```bash
-# For Tmux VirtualEnv support
-tmux_get_var(){
-    local key=$1
-    [[ -n "$TMUX" ]] && tmux showenv | awk -F= -v key="$key" '$1==key {print $2}'
-}
-
-# activate the virtual environment if it is declared
-venv=$(tmux_get_var "VIRTUAL_ENV")
-if [ -n "$venv" ]; then
-    source $venv/bin/activate;
-fi
+$ ./scada.js/venv
+(scadajs1) $ 
 ```
 
-2. Set the `VIRTUAL_ENV` variable for the target session:
+By setting the Tmux's `SCADAJS_VENV_PATH` variable, `./scada.js/venv` script uses this 
+virtual environment by default. If you want to start a different virtual environment in your 
+new pane: 
 
 ```bash
-tmux setenv -t ${SESSION_NAME} 'VIRTUAL_ENV' /path/to/virtualenv/
+$ ./scada.js/venv /path/to/your/other/virtual-environment
+(something) $ 
 ```