Question

您好我是rails的新手，每当我尝试查看服务器时，我都会得到这个

testapp$ rails s
/home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/execjs-2.5.2/lib/execjs/runtimes.rb:48:in `autodetect': Could not find a JavaScript runtime. See https://github.com/rails/execjs for a list of available runtimes. (ExecJS::RuntimeUnavailable)
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/execjs-2.5.2/lib/execjs.rb:5:in `<module:ExecJS>'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/execjs-2.5.2/lib/execjs.rb:4:in `<top (required)>'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/uglifier-2.7.1/lib/uglifier.rb:3:in `require'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/uglifier-2.7.1/lib/uglifier.rb:3:in `<top (required)>'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/bundler-1.9.9/lib/bundler/runtime.rb:76:in `require'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/bundler-1.9.9/lib/bundler/runtime.rb:76:in `block (2 levels) in require'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/bundler-1.9.9/lib/bundler/runtime.rb:72:in `each'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/bundler-1.9.9/lib/bundler/runtime.rb:72:in `block in require'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/bundler-1.9.9/lib/bundler/runtime.rb:61:in `each'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/bundler-1.9.9/lib/bundler/runtime.rb:61:in `require'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/bundler-1.9.9/lib/bundler.rb:134:in `require'
    from /home/sky/testapp/config/application.rb:7:in `<top (required)>'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/commands_tasks.rb:78:in `require'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/commands_tasks.rb:78:in `block in server'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/commands_tasks.rb:75:in `tap'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/commands_tasks.rb:75:in `server'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands.rb:17:in `<top (required)>'
    from /home/sky/testapp/bin/rails:8:in `require'
    from /home/sky/testapp/bin/rails:8:in `<top (required)>'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/spring-1.3.6/lib/spring/client/rails.rb:28:in `load'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/spring-1.3.6/lib/spring/client/rails.rb:28:in `call'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/spring-1.3.6/lib/spring/client/command.rb:7:in `call'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/spring-1.3.6/lib/spring/client.rb:26:in `run'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/spring-1.3.6/bin/spring:48:in `<top (required)>'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/spring-1.3.6/lib/spring/binstub.rb:11:in `load'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/spring-1.3.6/lib/spring/binstub.rb:11:in `<top (required)>'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from /home/sky/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from /home/sky/testapp/bin/spring:13:in `<top (required)>'
    from bin/rails:3:in `load'
    from bin/rails:3:in `<main>'

做什么？

Answer 1

您应该确保在Gemfile中声明了JS运行时。

尝试添加：

gem 'execjs'

或

bundle install

到您的Gemfile并运行：

class MyEventFilter : public QObject
{
public:
    MyEventFilter(QObject *parent = 0) : QObject(parent)
    {}

    bool eventFilter(QObject *obj, QEvent *e)
    {
        if (e->type() == QEvent::Paint)
        {
            QPaintEvent *ptrPaintEvent = static_cast<QPaintEvent *>(e);

            // depending on whether or not you want to have a default handling for this:
            // QObject::eventFilter(obj, e);
            // OR better to apply to specific event handler, pass widget as parent for this filter object for that 
            // static_cast<QWidget*>(parent())->paintEvent(ptrPaintEvent);

            // now do same thing as you would in paintEvent()
            return true;
        }
        // standard event processing
        return QObject::eventFilter(obj, e);
    }
};

// and attach it to just any widget
myWidget->installEventFilter(new MyEventFilter(myWidget));

Answer 2

如上所述，您需要一个JavaScript运行时。如果您不确定选择哪个，我总是被告知使用Node.js

rails 4.2.1服务器错误

2 个答案: