johntitus/node-horseman

Add support for polyfilling missing PhantomJS JavaScript features

Open

#230 aberto em 27 de out. de 2016

Ver no GitHub
 (7 comments) (2 reactions) (0 assignees)JavaScript (1.467 stars) (134 forks)batch import
enhancementhelp wanted

Description

PhantomJS does not support some features that websites expect it to. It would be nice for horseman to have built-in support for polyfilling these features.

Here is a way I came up with for polyfilling externally with Polyfill.io, for reference. It is somewhat gross, so if someone comes up with a better way that's great.

var Horseman = require('node-horseman');
var POLYURL = 'https://cdn.polyfill.io/v2/polyfill.min.js';

var horseman = new Horseman();

horseman
    .userAgent()
    .then(function(useragent) { // Get Polyfill based on real UserAgent
        return this.download(POLYURL + '?ua=' + useragent);
    })
    .then(function(polyfill) {
        // Make polyfill into function
        var polyfun = new Function(polyfill);
        // Wrap function in evaluateJavaScript
        var onInit = new Function(
            'console.log("onInitialized");' +
            'page.evaluateJavaScript(' + polyfun.toString() + ')'
        );
        // Call before page loads
        return this.at('initialized', onInit);
    })
    /* Do horseman stuff now */

Assistance/contribution would be greatly appreciated.

Guia do colaborador

Pilha de tecnologia
javascriptnodejs
Domain
tooling
Tipo Issue
feature
DifficultyDificuldade de implementação estimada para um novo contribuidor, de 1 para alterações muito pequenas a 5 para trabalho de nível especializado.
3
Tempo estimadoUm intervalo de tempo aproximado para um colaborador experiente investigar, implementar, testar e preparar um pull request.
half day
Status da atividadeQuão disponível o issue aparece agora: novo, ativo, obsoleto, bloqueado ou aguardando entrada do mantenedor.
stale
ClarityCom que clareza o issue explica a mudança esperada, os critérios de aceitação e a próxima etapa.
mostly clear
Prerequisites
JavaScriptNode.jsPhantomJS basicsPolyfill concepts
Simpatia para novatosUma pontuação de 1 a 100 que estima o quão acessível este issue é para colaboradores iniciantes.
55
Direção de pesquisa
The issue requests a built in polyfilling mechanism. A suggested approach uses the 'initialized' event and page.evaluateJavaScript. Newcomers should examine the Horseman source code to understand the event lifecycle and how to inject scripts before page load. They may also research other polyfill options like polyfill.io or custom polyfills.