https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URLs
DATA lv_filetype TYPE char4.
DATA lv_content TYPE xstring.
" get your data, for example a jpg
" lv_filetype = 'jpg'
" lv_content = ....
DATA(mimetype) = /iwwrk/cl_mgw_workflow_rt_util=>get_mime_type_from_extension( lv_filetype ).
DATA(base64) = /iwwrk/cl_mgw_workflow_rt_util=>base64_encode( lv_content ).
DATA(lv_data_url) = |data:{ mimetype };base64,{ base64 }|.
API Reference IconPool: https://sapui5.hana.ondemand.com/sdk/#/api/sap.ui.core.IconPool
In my case I used a custom formatter and the getIconForMimeType() function from the IconPool to get the required Icons for my list items.
myView.xml
icon="{path: 'mimeType', formatter: '.formatter.getIconForMimeType'}">
formatter.js
getIconForMimeType: function(sMimeType) {
return sap.ui.core.IconPool.getIconForMimeType(sMimeType)
}