Adding SplitChar Support

README.md

@@ -23,14 +23,35 @@ jobs:
   build:
     runs-on: windows-latest
     steps:
-    - uses: microsoft/variable-substitution@v1 
+    - uses: microsoft/variable-substitution@latest
       with:
         files: 'Application/*.json, Application/*.yaml, ./Application/SampleWebApplication/We*.config'
       env:
         Var1: "value1"
         Var2.key1: "value2"
         SECRET: ${{ secrets.SOME_SECRET }}
 
+ ```
+Define `splitChar` to change the character used to split the environment variable names for variable identification and substitution
+ ```yaml
+# .github/workflows/var-substitution.yml
+on: [push]
+name: variable substitution in json, xml, and yml files
+
+jobs:
+  build:
+    runs-on: windows-latest
+    steps:
+    - uses: microsoft/variable-substitution@latest
+      with:
+        files: 'Application/*.json, Application/*.yaml, ./Application/SampleWebApplication/We*.config'
+        splitChar: '__'
+      env:
+        Var1: "value1"
+        Var2__key1: "value2"
+        Var3__key1__key2: "value3"
+        SECRET: ${{ secrets.SOME_SECRET }}
+
  ```
 # Contributing
 

action.yml

@@ -5,6 +5,10 @@ inputs:
   files:
     description: 'comma separated list of XML/JSON/YAML files in which tokens are to be substituted. Files names must be specified relative to the folder-path.'
     required: true
+  splitChar:
+    description: 'The character within the environment variables used to split the name for variable location.  This defaults to `.`'
+    require: false
+    default: '.'
 runs:
   using: 'node12'
   main: 'lib/variableSubstitution.js'