modified

Modified is a simple request client to deal with http local cache.

Modified implemented last-modified, if-modified-since, etag, if-none-match of HTTP specifications.

Synopsis

Modified is built upon request and flavors it with cache support, so if you are familiar with request, you are almost ready to use modified.

var modified = require('modified');
var request = modified(options); // Then use it almost the same as request
 
request('http://google.com/doodle.png').pipe(fs.createWriteStream('doodle.png'));

Usage

If your server supports etag, or checks the if-modified-since header, modified will manage the local cache for you.

Specify the cache routing

If options.cacheMapper is not specified, caches will be saved into '~/.node_modified/' directory by default.

But you can do it yourself for better control.

var request = modified({
    cacheMapper: function(options, callback){
        // your code...
        callback(
            null, 
            path.join(
                pathToSaveNpmCache,
                url.parse(options.uri).pathname,
                'couchdb-document.json'
            )
        );
    }
});
 
request({
    method: 'GET',
    url: 'http://registry.npmjs.org/modified'
    
}, function(err, res, body){
    // ...
})

cache_file

String

The file path of the local cache to save response body according to a specific request. (Response headers will be saved into cache_file + '.modified-headers.json')

If you don't want modified to cache for a certain request, cache_file should be set to null

{
    cacheMapper: function(options, callback){
        var path = url.parse(options.url).pathname;
        
        if (path) {
            // 'http://xxx.com/abc/' -> '/abc'
            path = path.replace(/\/$/, '');
            
            callback(
                null, 
                // Where the cache should be saved.
                path.join(__dirname, 'cache', path)
            );
        
        } else {
            callback(null, null);
        }
    }
}

With options.cacheMapper, you could specify the paths where the cache will be saved.

Programmatical APIs

var request = modified(options);

• options Object
  • cacheMapper function() Which is described above

request(options, callback)

modified(options) returns a function which acts nearly the same as request;

Returns

request(options, callback) returns an instance of modified.Modified which is a sub-class of Readable Stream.

A instance of Modified is an EventEmitter with the following extra event(s):

Event: 'complete'

• response http.ServerResponse The response object
• body String The response body

Emitted when all the request process is complete, after the execution of user callback (the one of request(options, callback)).

Release History

• 2.0.0 - Completely redesigned.

• 1.1.0 - Modified instances are streams now. You can use modified to fetch binary files.

• 1.0.0 - Initial release