Package: Kernel-HTTP

Class: HTTPClient

Introduction

Environment: container

HTTPClient is a HTTP client library.

It has the following attributes:

• host the host of the request

• port the port of the request

• url the url of the request

• timeout the timeout of the request

• contents the contents of the request

• contentType the content type of the request

• method the http request method.

It has the following methods:

• queryAt:put: Add key equals value as an HTTP query parameter to the current request.

• headerAt:put: Add key equals value as an HTTP header to the current request.

• execute execute the request

• get execute a get request

• put execute a put request

• post execute a post request

• delete execute a delete request

• head execute a head request

You can use it to make HTTP requests to a server.

for example, for a HTTP get:

httpClient := HTTPClient new.
httpClient url: 'http://www.example.com'.
result := httpClient get.

and for a HTTP post:

httpClient := HTTPClient new.
httpClient url: 'http://www.example.com/api'.
httpClient
 contents:
 { ('key1' -> 'key1').
   ('key2' -> 2) } asJson.
result := httpClient post.

The result is a Dictionary which has three keys:

• status The http status code.

• headers The http headers.

• response The http response body. It wil be parsed as JSON if possible, otherwise it will be a string.

For example, you can check the status code like this:

result := httpClient get.
" If the HTTP status code differs from 200, exit the current block. "
(result at: 'status') = 200 ifFalse: [ ^ nil ].

Sometimes, the http request may raise an error for a failure request, we can catch error like this:

error := nil.
[ httpClient get ] onErrorDo: [ :ex | error := ex ].
" If error is not nil, it means the http request failed. "
error ifNotNil: [
  " The error is an APIError object, we can check the error code like this: "
  error code = 'http-request-error'.
  "we can terminate the execution by caret operator.  "
  ^ nil ].

Instance Method

Category: accessing - request

• contentType - Get the contentType of the HTTPClient.

• contentType: - Set the contentType of the HTTPClient.

• contents - Get the contents of the HTTPClient.

• contents: - Set the contents of the HTTPClient.

• headerAt:put: - Set key equals value in the HTTP header of the current request.

  For example:

  self headerAt: 'x-conversation-id' put: UUIDGenerator next.

• host - Get the host of the HTTPClient.

• host: - Set the host of the HTTPClient.

• method - Get the method of the HTTPClient.

• method: - Set the method of the HTTPClient.

• port - Get the port of the HTTPClient.

• port: - Set the port of the HTTPClient.

• queryAt:put: - Add key equals value as an HTTP query parameter to the current request.

  If a key is already present, its corresponding value will be replaced.

  For example:

  self queryAt: 'id' put: '12'.

• timeout - Get the timeout of the HTTPClient.

• timeout: - Set the timeout of the HTTPClient.

• url - Get the url of the HTTPClient.

• url: - Set the url of the HTTPClient.

Category: operations

• delete - Execute an HTTP DELETE the request set up and return the response #contents.

• execute - Execute the currently set up request to generate a response. Return the #contents of the response, if any.

• get - Execute an HTTP GET the request set up and return the response #contents.

• head - Execute a HTTP HEAD on the request set up and return nil.

• post - Execute an HTTP POST the request set up and return the response #contents.

• put - Execute an HTTP PUT the request set up and return the response #contents.

Class: UUIDGenerator

Introduction

Environment: container

The UUIDGenerator generates UUIDs, this can be used by following the syntax below

"Return a new UUID string."
UUIDGenerator next

Class Method

Category: accessing

• next - returns a new UUID string.