DockModal.js A vanilla, lightweight (~8kb gzipped), configurable. Fork jquery.dialog.js but without the jQuery dependency.

SETUP

js

dockModal(document.querySelector(".dock_modal"), {
    minimizedWidth: 240,
    class: 'dockmodal_test',
    height: 420,
    title: function() {
        return document.querySelector(".dock_modal").getAttribute("data-title");
    },
    initialState: "minimized"
});

html

<div class="dock_modal" data-title="test_title">    
    test content
</div>

callback function:

beforeCreate: undefined,
create: undefined,
open: undefined,
beforeClose: undefined,
close: undefined,
beforeMinimize: undefined,
minimize: undefined,
beforeRestore: undefined,
restore: undefined,
beforePopout: undefined,
popout: undefined

demo: https://reimax.github.io/dockModal/public/