How can I create links directly without using link dialog ?

For creating links directly per API please use editCreateLink method

//editCreateLink(url,target,title,inText,inMisc,inId,inTrail)

Sample if link text shall be created:
editor.editCreateLink("http://www.pintexx.com","_self","MyLink","Link to pintexx","style='color:red'","myid",false)

Sample if a text selection is available in editor:
editor.editCreateLink("http://www.pintexx.com")