Joe Strummer was a mensch. That’s one thing the makers of “London Town,” which opened Friday in New York and Los Angeles, want you to know about the late frontman of The Clash. Set in 1979 in working-class London, the film, directed by Derrick Borte (“The Joneses”) and written by Matt Brown, Sonya Gildea and Kirsten Sheridan (“In America”), is a coming-of-age story laced with the political upheaval circumstances of the time: the rise of Thatcherism, hate groups protesting immigration, general malaise. The antidote, especially for the young, was a new, more intellectual, more proudly-leftist brand of punk rock. That which arrived in the form of The Clash.

“London Town” centers on Shay (Daniel Huttlestone of “Into the Woods”), a fifteen year-old from the suburbs who gets turned on to The Clash by both his estranged mother (Natascha McElhone) and a beautiful punk rocker girl (Nell Williams). The band provides solace from a rather joyless life: Shay is bullied by schoolmates and he’s pushed around by a single dad (Dougray Scott) working a double-shift, which forces Shay to care for his little sister.

Despite the turbulent context “London Town” strikes a sweet tone. And the sweetest aspect turns out to be Jonathan Rhys Meyers’s depiction of Strummer. He meets Shay twice, via comically serendipitous events, and both times acts as a mentor and beneficiary—-he gives the kid wads of cash.

Making a feel-good movie about one of rock music’s fiercest bands is a challenging feat, but it’s one the filmmakers were hellbent on pulling off. “We heard countless stories about how Joe really acted like a guardian angel to people,” said Borte, who I spoke to for this article. In a beautiful twist of fate, he received the script from his agent after saying that his dream project would be about a kid discovering The Clash. “If you were in with him, he’d do anything in the world for you. That wasn’t his image on a poster, but that was the real Joe.”

Some of the film’s critics, myself included, didn’t quite buy this version of Joe Strummer, which Borte understands but finds frustrating.

“I’m glad that Clash fans are passionate. And when one of them makes a film about The Clash, I’ll be the first one in line to buy a ticket for it,” he said. “But I wish the film was marketed as a kids’ film, for thirteen to fifteen year-olds, because that’s what it is. When I see the reaction of the kids, and the adults that [sic] aren’t expecting a biopic, it tells me that being proud of this movie is the right thing to feel. I think it’s a really good movie that’s gonna get people to talk about the band and buy the music.”

“London Town” fell into Borte’s lap six years ago. The film took a long time to develop because of financing and casting issues. One cast member who was on board from the start and never left, however, was Jonathan Rhys Meyers. “Johnny was always gonna play Strummer. He’s so talented, he’s incredibly musical. It was the right fit. He’s a guy who played Elvis, and kind of a Bowie hybrid in Velvet Goldmine.” Borte added, “he sings and plays in the movie, as do the other people depicting the rest of the Clash, some of whom were found hanging out around music stores in SoHo.”

Beyond the music, “London Town” strives for authenticity in the setting, also. It was shot in a fleet twenty-four days in London last summer. And, due to the very strict child labor laws in England and the many night sequences in the film, Borte was forced, during the shooting of several sequences, to think on his feet at the zero hour. The scene in which Strummer and Shay meet, and then a car chase ensues, followed by a heartfelt conversation, was scheduled to be shot on the longest day of the year. As Borte describes it, “it got dark really late, and kids have to be off the set in England by 10:30 p.m. sharp, even with a waiver. There was a child welfare person on set, literally standing there with a watch. So we had to shoot all that in an hour and a half. We had two cameras mounted to the car, because I didn’t have time to take the cameras off the rigs [as planned]. We even had a body double, a fifty year old-woman who’s the same size as Daniel, standing by” (not that that scenario would have been as bizarre as it sounds, as Huttlestone, for reasons too complicated to get into here, is dressed in drag throughout the scene).

The film’s many concert riot scenes also posed staging hurdles for Borte: “we didn’t have enough extras given the low budget,” he said. “There were maybe thirty people and it looks like there’s a hundred. We had the same people playing cops, rioters and skinheads, all in the same scene.”

Borte, however, loved the guerilla-style filmmaking. The shoot, which was his favorite to date, was a substantially looser experience than, say, his work on the glossier “The Joneses.”

“There weren’t any slow, big dolly moves or shots that would draw attention to the cinematography,” he explained.

Borte has just one regret: he was forced to cut his wife and children, who stayed with him in London throughout the shoot and appeared as extras, from the final print. “My wife was dressed in a 1979 costume, walking by this house on the street, but because I did a jump cut to the house door, you don’t see her,” he said. “But you can’t cut a film to keep your wife and kid in the movie. You do what’s best for the film.”

Asked if his children was understanding of this professional decision, Borte, with typical crack comic timing, replied: “A little bit.”

“London Town” had its world premiere at the Los Angeles Film Festival in June 2016. Film is out in select theaters this month.