Variable spec.

- definition doc
- example doc

Author: 0hsn

docs/04-Examples/041-http-examples.md

@@ -11,6 +11,9 @@ title: Http spec. examples
 Case-wise more example can be found in `tests/resources/storage/sample_config` directory of [https://github.com/chkware/cli](https://github.com/chkware/cli/tree/main/tests/resources/storage/sample_config) repository
 :::
 
+
+## Request examples
+
 Following examples are using HTTP _GET_ and _POST_ method. Although all these example are still valid for _POST_, _PUT_, _PATCH_, _DELETE_, _OPTIONS_, _HEAD_ method as well. You can still send a request body with _GET_ or _HEAD_ method for the sake of testing API.
 
 ### Minimal request with HTTP GET method
@@ -252,3 +255,54 @@ request:
       </book>
     </catalog>
 ```
+
+---
+## Request using variable examples
+
+We can also use variables inside a http specification file. See examples below. 
+
+** * This is highly experimental. Report any bug you can find.**
+
+### Request with query string using variables
+
+```yaml
+---
+version: default:http:0.7.2
+
+# define local variables
+variables:
+  Foo: 'bar'
+  Two: 2
+  Server: https://example.org/api
+
+request:
+  # put variables on the path for query string
+  url: {$Server}/path?foo={$Foo}&two={$Two}
+  method: GET
+```
+
+### Request with basic authentication header using variables
+
+```yaml
+---
+version: default:http:0.7.2
+
+# define local variables
+variables:
+  userName: Some_USER
+  password: Some-P@$$W03D
+  content_type: application/json
+  Server: https://example.org/api
+
+request:
+  url: {$Server}/resource/id
+  method: GET
+
+  headers:
+    Accept-Encoding: gzip, deflate
+    Content-Type: {$content_type}
+
+  auth[basic]:
+    username: {$userName}
+    password: {$password}
+```

docs/05-References/053-variable-reference.md

@@ -0,0 +1,31 @@
+---
+title: Variable specification reference
+---
+
+:::note
+- This page should be use as reference for specification files.
+- This page is subject to change. It is requested to check this page frequently.
+:::
+
+### Introduction
+
+Variables are ways to hold value or computed values, like in programming language.
+
+### Definition
+
+Variables can be defined in two ways:
+
+1. Variable specification file. Files with `version: default:variable:x.x.x` [**WIP**]
+2. `variables` section on a supported specification document. See below.
+    ```yaml
+    version: default:http:0.7.2
+
+    variables:
+      var1: value one
+      var_2: 'value 2'
+    ...
+    ```
+
+### Supported specification document
+
+- [Http specification document examples](/Examples/http-examples#variable-examples) | [More example](https://github.com/chkware/cli/tree/0272b83c2975349fd3f0d94e1646cc27b603eaf5/tests/resources/storage/sample_config/pass_cases/variables)