Whole notes with slurs are treated as if they had stems. At the end of a line, slurs should not extend past the barline. If there is a change of meter at the end of the line, the slur still only extends to the barline. At the beginning of the next line, the slur begins right after the clef. If there is a change of meter or at the beginning of the line, the slur begins right after the time or key signature.
Slurs often conflict with flagged notes.
It is best to place slurs outside of the staff and away from the flags, for clarity. When there are ties in the chord as well, the slurs and ties should cuve in opposite directions from each other. Long slurs can never connect two notes of the ssme pitch. Long slurs are placed the same way as short slurs, but they usually enclose all the ties, beams, articulations, fingerings, trills, etc. Long slurs must start and end over or under the center of a notehead.