icrawler

Tool for easy scraping data from websites

Features

• Clean and simple API
• Persistent error-proof crawling
• State saving for continuous crawling
• jQuery-like server-side DOM parsing with Cheerio
• Parallel requests
• Proxy list and user-agent list support
• HTTP headers and cookies setup
• Automatic charset detection and conversion
• Console progress indicator
• node from 0.10 to 6.0 support

Install

npm install icrawler

Usage

icrawler(startData, opts, parse, done);

• startData - task for start crawling (or array of tasks). Single icrawler task can be url (of page or API resource) or object with url field for url. Optionaly you can use data field with object for POST request (default method is GET). You can use any other fields for custom data. For example, you can mark different types of tasks for parsing different ways, or you can store in task partial data, when one result record needs more than one requests.
• opts (optional) - options:
  • concurrency - positive number of parallel requests or negative number of milisecs of delay between requests with no parallelism. Defaults to 1.
  • delay - time in milisecs to wait on error before try to crawle again. Defaults to 10000 (10 secs).
  • errorsFirst - if true failed requests will repeated before all others. if false - it will pushed in tail of queue. Defaults to false.
  • allowedStatuses - number or array of numbers of HTTP response codes that are not errors. Defaults to [200].
  • skipDuplicates - if true parse every URL only once. Defaults to true.
  • objectTaskParse - if true task object will sent to parse instead url string. Defaults to false.
  • decode_response - (or decode) Whether to decode the text responses to UTF-8, if Content-Type header shows a different charset. Defaults to true.
  • noJquery - if true send response body string to parse function (as $ parameter) as is, without jQuery-like parsing. Defaults to false.
  • noResults - if true don't save parsed items to results array (no save field in _ parameter of parse function). Defaults to false.
  • quiet - if true don't write anything to console. No log and step fields in _ parameter of parse function. Defaults to false.
  • open_timeout (or timeout) - Returns error if connection takes longer than X milisecs to establish. Defaults to 10000 (10 secs). 0 means no timeout.
  • read_timeout - Returns error if data transfer takes longer than X milisecs, after connection is established. Defaults to 10000 milisecs (not like in needle).
  • proxy - Forwards request through HTTP(s) proxy. Eg. proxy: 'http://user:[email protected]:3128'. If array of strings - use proxies from list.
  • proxyRandom - if true use random proxy from list for every request; if false after each error use new proxy from list. Defaults to true. If proxy is not array - proxyRandom option will be ignored.
  • reverseProxy - Replace part of url before request fot using reverse proxy. If reverseProxy is string, it'l be used instead protocol and domain of original url. If reverseProxy is object, in original url substring reverseProxy.to will be replaced by reverseProxy.from. If array of strings or objects - use reverse proxies from list.
  • reverseProxyRandom - if true use random reverse proxy from list for every request; if false after each error use new reverse proxy from list. Defaults to true. If reverseProxy is not array - reverseProxyRandom option will be ignored.
  • headers - Object containing custom HTTP headers for request. Overrides defaults described below.
  • cookies - Sets a {key: 'val'} object as a 'Cookie' header.
  • connection - Sets 'Connection' HTTP header. Defaults to close.
  • compressed - if true sets 'Accept-Encoding' HTTP header to 'gzip, deflate'. Defaults to false.
  • agent - Sets custom http.Agent.
  • user_agent - Sets the 'User-Agent' HTTP header. If array of strings - use 'User-Agent' header from list. Defaults to Needle/{version} (Node.js {nodeVersion}).
  • agentRandom - if true use random 'User-Agent' from list for every request; if false after each error use new 'User-Agent' from list. Defaults to true. If user_agent is not array - agentRandom option will be ignored.
  • onError - function (err, task) for doing something on first error before pause.
  • init - function (needle, log, callback) for preparing cookies and headers for crawling. Must run callback(err) if errors or callback(null, cookies, headers) if success.
  • initOnError - if true run init on every resume after errors. If false run init only on start. If init is not set - initOnError option will be ignored. Defaults to true.
  • cleanCookiesOnInit - if true clean old cookies on init run. Defaults to false.
  • cleanHeadersOnInit - if true clean old headers on init run. Defaults to false.
  • save - function (tasks, results) for saving crawler state. tasks is object containing arrays waiting, finished and failed with tasks from queue. results is array of already fetched data. Ignored if file set.
  • results - results saved by save for continue crawling after crash or manual break. Ignored if file set.
  • tasks - tasks saved by save for continue crawling after crash or manual break. tasks is object containing arrays waiting, finished and failed. Ignored if file set.
  • file - name of file for saving crawler state for continue crawling after crash or manual break. Use it instead save, tasks and results for auto saving.
  • saveOnError - if true runs save every time when paused on error. Defaults to true.
  • saveOnFinish - if true runs save when crawling finished. Defaults to true.
  • saveOnExit - if true runs save when user abort script by Ctrl+C. Defaults to true.
  • saveOnCount - if number runs save every saveOnCount requests.
  • asyncParse - if true - runs parse in asynchronous mode. Defaults to false.
• parse - page-parsing function(task, $, _, res) , that runs for every crawled page and gets this params:
  • task - url of parsed page. If set objectTaskParse then task is object with url property.
  • $ - jQuery-like (cheerio powered) object for html page or parsed object for json or raw response body if noJquery is true.
  • _ - object with four functions:
    • _.push(task) - adds new task (or array of tasks) to crawler queue (will be parsed later). Every task can be url string or object with url property.
    • _.save(item) - adds parsed item to results array
    • _.step() - increment indicator
    • _.log(message /*, ... */) - safe logging (use it instead console.log)
    • _.cb - callback function for asynchronous mode. Is undefined if asyncParse is false.
  • res (optional) - full response object (needle powered).
• done (optional) - function(result), that runs once with result of crawling/parsing

Example

var icrawler = require('icrawler');

var opts = {
    concurrency: 10,
    errorsFirst: true
};

icrawler('http://example.com/', opts, function(url, $, _){
    if($('#next').length > 0){
        _.push($('.next').attr('href'));
        _.log('PAGE');
    }
    $('.news>a').each(function() {
        _.step();
        _.save({
            title: $(this).text(),
            href: $(this).attr('href')
        })
    });
}, function(result){
    console.log(result);
});

Some real life examples:

• icrawler-ferra
• icrawler-lis

License

MIT