how to dynamically change content

Very import to set a function for content:

$el.popover({
html: true,
trigger: 'manual',
placement: 'auto',
content: function() {return return_html.html()},
sanitize: false
}).popover('toggle');

Once the popover is hidden, the properties can not be set. Otherwise the properties can be accessed by $(‘#target’).data(‘bs.popover’).config (.content etc)