How to embed a url variable using leaflet bindpopup

My question is I have a variable called 'url' and I want it to show up in the popup. However, this is not working <a href = feature.properties.url >Website</a>. Also this leaflet code is integrated with rChart. My original codes are as below:

map$geoJson(toGeoJSON(df2_sub_list, lat = 'venue_lat', lon = 'venue_lng'),
                onEachFeature = '#! function(feature, layer){

                layer.bindPopup(feature.properties.venue_name + \'</br><a href =
                               feature.properties.url> Website </a>\')
  } !#',
                pointToLayer =  "#! function(feature, latlng){
                return L.circleMarker(latlng, {
                radius: 4,
                fillColor: feature.properties.colors || 'red',    
                color: '#000',
                weight: 1,
                fillOpacity: 0.8
                })
} !#"

Solution

You're not concatenating your HTML string and variable properly and using spaces in your attribute assignment:

feature.properties.venue_name + \'</br><a href = feature.properties.url> Website </a>\'

Should be:

feature.properties.venue_name + \'</br><a href=\' + feature.properties.url + \'> Website </a>\'

Also, you're not quoting your attribute value but that shouldn't be a problem if you're using HTML5.