如何在 casperjs 中正确设置间隔？

Question

我尝试使用网络服务器与外界对话，setInterval 有时希望它自动执行。

我的 casperjs 设置之一是 this.capture(x + 'apple.png');

如果 setInterval 运行三次，我的文件夹下会显示三张图片。

结果我只保存了一张图片是1apple.png。

虽然我可以在我的终端上看到很多信息

我想问一下我应该错过哪一步？任何帮助，将不胜感激。提前致谢。

这是我的代码today.js:

var webserver = require('webserver');
var server = webserver.create();
var service = server.listen('8080', {
    'keepAlive': true
}, function (request, response) {
    response.statusCode = 200;
    response.write('<html><body>What the hell~~</body></html>');
    var casper = require("casper").create({
        verbose: true,
        logLevel: 'debug',     // debug, info, warning, error
        pageSettings: {
            loadImages: false,
            loadPlugins: false,
            userAgent: 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_5) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4'
        }
    });

    var movieTitle = [];
    var movieEnTitle = [];
    var title = [];
    var movieTime = [];
    var movieVersion = [];
    var city = '台南';
    var latitude = 22.993089;
    var longitude = 120.196876;
    var theaterName = '今日戲院';
    var data = {};
    data.theater = [];
    data.movie = [];
    var x =1;

    function getMovieTitle() {
        var title = document.querySelectorAll('div.theaterlist_name a');
        return Array.prototype.map.call(title, function (e) {
            return e.innerText;
        });
    };

    function getEnTitle() {
        var title = document.querySelectorAll('div.en a');
        return Array.prototype.map.call(title, function (e) {
            return e.innerText;
        });
    };

    function getMovieTime() {
        var title = document.querySelectorAll('ul.theater_time');
        return Array.prototype.map.call(title, function (e) {
            return e.innerText;
        });
    };

    function getMovieVersion() {
        var version = document.querySelectorAll('div.tapR');
        return Array.prototype.map.call(version, function (e) {
            return e.innerText;
        });
    };

    // 台南 今日戲院 from 奇摩
    casper.start('https://tw.movies.yahoo.com/theater_result.html/id=67', function () {
        this.echo(this.getTitle());
    });

    casper.then(function () {
        this.echo('Image');
        this.echo(x);
        this.capture(x + 'apple.png');
        x++;
    });

    casper.then(function () {
        movieTitle = this.evaluate(getMovieTitle);
        movieEnTitle = this.evaluate(getEnTitle);
        movieTime = this.evaluate(getMovieTime);
        movieVersion = this.evaluate(getMovieVersion);
    });

    casper.then(function () {
        console.log('Print:\n');
        this.echo(movieTitle.length + ' Movie title found :\n');
        this.echo(movieTitle.join('\n'));
        this.echo(movieEnTitle.length + ' Movie title found :\n');
        this.echo(movieEnTitle.join('\n'));
        this.echo(movieTime.length + ' Movie time found :\n');
        this.echo(movieTime.join('\n'));
        this.echo(movieVersion.length + ' Movie version found :\n');
        this.echo(movieVersion.join('\n'));

        this.echo(outPutJSON());
    });

    function outPutJSON() {

        data.theater.push({
            name: theaterName,
            city: city,
            latitude: latitude,
            longitude: longitude
        });

        // 將中英文名字合併
        for (var i = 0; i < movieTitle.length; i++) {
            title.push(movieTitle[i] + movieEnTitle[i]);
        }
        for (var i = 0; i < movieTime.length; i++) {
            var name = title[i];
            var sourceTime = movieTime[i].match(/.{1,5}/g);
            var times = [];
            times.push(sourceTime);
            var version = movieVersion[i];

            data.movie.push({
                name: name,
                version: version,
                time: times
            });
        }
        return JSON.stringify(data);
    }

    // casper.run(function () {
    //     // this.echo('Done').exit();
    //     this.echo('Done');      
    // });

    setInterval(function () {
        casper.run(function () {
            // this.echo('Done').exit();
            this.echo('Done');      
        });
    }, 2000);

    response.write(outPutJSON());
    response.close();
});

这是我命令这个文件时的文件夹，你只能看到一次捕获图像1apple.png。

Answer 1

实现您想要的目标的一种方法是让 cron 作业以所需的频率抓取站点并将结果放入网络服务器提供的目录中。下面是一个 stand-alone 脚本，它将每小时获取一次网站的标题和图像。修改 this.step 可能是不明智的（灵感来自这个网站： https://github.com/yotsumoto/casperjs-goto)

var casper = require('casper').create();
var x = 0;

casper.start('http://localhost:8080', function() {
// change 'http://localhost:8080' to the site to be scraped
  this.echo(this.getTitle());
  this.capture(x++ + '.png');
  this.wait(60 * 60 * 1000, function() {
// 60 minutes * 60 seconds * 1000 milliseconds
    this.step = 0;
  });
});

casper.run();

如何在 casperjs 中正确设置间隔？

How to setInterval correct in casperjs?

javascript

casperjs