JHRW - JavaScript HTTP Request Wrapper

A wrapper for so-called “AJAX” Requests

Goals

I’ve made JHRW to:

• Advance my JavaScript skills;
• Improve/Simplify the usage of the XMLHttpRequest object by:
  • Adding default values to what’s undefined;
  • Adding additional Error checking and clarification;
  • Adding interesting, simplified, feature, such as timeouts and retries.

Documentation

Object JHRW(String base, String urlPath [, Boolean lazyExecution = false [, Boolean bypassCache = false]]);

Parameters

• String base - The request’s base URL
• String urlPath - The request’s endpoint
• Boolean lazyExecution(optional) - If the request should be initialized and sent right after instantiation. Default: false
• Boolean bypassCache(optional) - If the request URL should have a timed parameter added in order to bypass cache. Default: false

Throws

• A ReferenceError
  • If there’s no JHRWHandler function defined.
• A Error
  • if the base parameter is undefined
  • if the urlPath parameter is undefined
• A TypeError
  • if the base parameter is not a String
  • if the urlPath parameter is not a String
  • if the lazyExecution parameter is not a Boolean
  • if the bypassCache parameter is not a Boolean

Returns

An Object containing:

Properties

• Object request - The native XMLHttpRequest Object
• Object config - The configuration Object
  • String URI - The request’s target
  • Boolean asynchronous - If the request should be asynchronous
  • String verb - The HTTP verb
  • Mixed data - Data to be sent along with the request
  • Object requestHeaders - HTTP headers for the request
  • String responseType - Expected MIME type of the response
  • Object handlers - The functions to handle the request
  • Number attempts - # of attempts to retry if the request fails
  • Number attemptInterval - Interval between attempts, in seconds.
  • Number timeout - The timeout, in seconds, for the request - after which it should be retried.
  • Function postTimeout: The function to be executed if the request times out.
  • Number timer - The timer that controls the retry process.

Static Properties

• Array JHRW.availableHandlers: The types of handlers that can be [re-]defined.
• String JHRW.handlerList: Convenience property to be shown in error messages.

Methods

configure

void configure(Object configureObject);

Overwrites one or more configuration options (see the config object above)

init

void init();

Initializes the request: Sets the expected response MIME Type; Sets the handlers as listeners; Opens the request; Sets the request’s headers.

send

void send();

Sends the request, including data, if available.

end

void end();

Ends the request. Useful if you wish for JHRW to stop retrying on success.

Basic Usage

try {
    var obj = new JHRW('http://localhost', /foo.php', true);
} catch (Error e) {
    // Do something
}

or

try {
    var req = new JHRW('http://localhost', 'foo.php');
    try {
        req.init();
    } catch (ReferenceError e) {
        // Do something
    }
    req.send();
} catch (Error e) {
    // Do something
}

For a more advanced usage example see the testing page.

Credits

• Developed by @galvao.
• Logo font: Neutra Text Bold