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REST Client variable syntax

REST Client variable syntax refers to the specific notation used within the Visual Studio Code REST Client extension to define, reference, and manipulate dynamic values in HTTP requests.^[600-developer__tools__vscode__RestClient-Postman.md]

Variable Definition

Custom variables are defined using the @ symbol at the beginning of a line, followed by the variable name and its value.^[600-developer__tools__vscode__RestClient-Postman.md]

Syntax: 

@VariableName = Value

Common usage examples include: * Host Configuration: Defining a base URL or domain to avoid repetition^[600-developer__tools__vscode__RestClient-Postman.md]. 

@localhostBWS = http://localhost:8080/business-web-service/resources
* Headers: Storing common header values such as User-Agent or Content-Type^[600-developer__tools__vscode__RestClient-Postman.md]. 
@ContentType = application/json

Variable Request Reference

Once defined, variables are referenced in request lines or headers using double curly braces {{ }}.^[600-developer__tools__vscode__RestClient-Postman.md]

Syntax: 

{{VariableName}}

This substitution mechanism allows for dynamic composition of request URLs and headers^[600-developer__tools__vscode__RestClient-Postman.md]. For example, a domain variable can be interpolated into the request path^[600-developer__tools__vscode__RestClient-Postman.md]:

@domain = {{localhostBWS}}
GET {{domain}}/workflow/allMission/count

Chained Requests and Response Capture

Variables can also derive their values from the response of a preceding request.^[600-developer__tools__vscode__RestClient-Postman.md] This allows for "chained" requests, such as performing a login and then using the returned session token in subsequent requests.

To enable this, the first request must be annotated with # @name^[600-developer__tools__vscode__RestClient-Postman.md].

Syntax: 

# @name RequestName

Subsequent variables can then access the response body using the syntax: {{RequestName.response.body.$.JSONPath}}^[600-developer__tools__vscode__RestClient-Postman.md].

Example: 1. Named Request: 

# @name loginCWS
POST {{domain}}/sessions HTTP/1.1
...
2. Variable Capture: 
@authToken = {{loginCWS.response.body.$.id}}
3. Usage: 
Authorization : {{authToken}}

Sources

^[600-developer__tools__vscode__RestClient-Postman.md]

  • [[REST Client]]
  • [[JSONPath]]
  • HTTP headers
  • [[Chained requests]]