Convert ggplot object to plotly in shiny application
<p>I am trying to convert a ggplot object to plotly and show it in a shiny application. But I encountered an error "no applicable method for 'plotly_build' applied to an object of class "NULL""</p>

<p>I was able to return the ggplot object to the shiny application successfully, </p>

<pre><code>output$plot1 &lt;- renderplot({
   gp &lt;- ggplot(data = mtcars, aes(x = disp, y = cyl)) + geom_smooth(method = lm, formula = y~x) + geom_point() + theme_gdocs()
})
</code></pre>

<p>but somehow plotly cannot convert it. </p>

<p>My code looks like this </p>

<pre><code>output$plot2 &lt;- renderplotly({
   gp &lt;- ggplot(data = mtcars, aes(x = disp, y = cyl)) + geom_smooth(method = lm, formula = y~x) + geom_point() + theme_gdocs()
   ggplotly()
})
</code></pre>