I’ve said before that the danger in being both writer and director of a film is there’s no one tell you you’re doing it wrong. And when the material is autobiographical, as it is in Richard E. Grant’s “Wah-Wah,” there’s even less objectivity.

Grant’s story of growing up in Swaziland in the 1960s, at the tail end of England’s colonial presence in the tiny South African country, is sweet and not without its charms. It ends well, too, which makes a viewer inclined to remember it more favorably than he should.

But the film is a hodge-podge of random plot threads, insignificant details and an often-melodramatic tone. A film in which a little boy prays, “Please make Mummy come back again and fix our broken family” deserves pity, not admiration.

That it winds up being moderately likable and even lukewarmly recommendable is a credit to its overall sunny disposition (maudlin little-boy prayers notwithstanding) and the sheer affection with which Grant infuses. Rare is the honest labor of love that doesn’t have some redeeming value, and “Wah-Wah” ultimately wins you over with its sincerity.

Grant has re-cast his family as the Comptons, with gin-soaked dad Harry (Gabriel Byrne), a British diplomat, glacial Lauren (Miranda Richardson), the Mummy who takes off, and little Ralph (Zachary Fox) in the Richard E. Grant role. Ralph has a facial tic that appears when he’s anxious, and he loves puppetry, to name just two details that have nothing to do with the story but that keep getting mentioned.

After two years at boarding school, Ralph comes home to find that 1) he is now played by Nicholas Hoult, the kid from “About a Boy,” and 2) his father has gotten remarried to a brassy American gal named Ruby (Emily Watson). Ralph resists Ruby’s attempts to ingratiate herself, but as Dad becomes fonder of the drink and less fun to be around, Ralph and Ruby become allies.

Ruby also has the distinction of being the lone non-snob in a sea of idle-rich British hoity-toities still lingering over their ownership of Swaziland. Kids Ralph’s age tend to see through all the bullcrap, and so does Ruby. “Wah-wah” is what she calls the uber-formal British manners and too-polite way of speaking that they have.

So, then. The plot? Well, the town is going to do a production of “Camelot” in honor of Princess Margaret’s visit, that’s something. Oh, and for a few minutes, it seems our focus should be on Harry Compton’s alcoholism. But then his first wife returns, frosty as ever, and our attention is diverted that way for a while. But no, then it’s Ralph’s crush on a girl his age, or the town’s snobbiest snob Lady Hardwick (Celia Imrie) getting her comeuppance, or Ralph and his buddy sneaking into a theater showing “A Clockwork Orange,” or some other slice-of-colonial-life vignette.

Nicholas Hoult, now a lanky 6’3″ and coming into his own as a teen actor, is impressive in what is essentially his first starring role, albeit with a great ensemble backing him up. Grant may have written and directed the film too wistfully and haphazardly, but Hoult keeps things grounded with a mature and funny performance. He helps make the film better than it ought to be.

B- (1 hr., 37 min.; R, a handful of F-words and other profanity, some sexuality, brief National Geographic style nudity.)