Joy of Life did not provide any specific information about the plot and development of Li Chengqian's novel.

Joy of Life was a novel in which the Crown Prince, Li Chengqian, was one of the characters. Prince Li Chengqian had an affair in the story, but the specific plot and ending were not mentioned in the search results provided. Therefore, I'm not sure about the plot and ending of Prince Li Chengqian's novel in Joy of Life.
Li Chengqian had written several novels in the past few years, including Li Chengqian, the impetuous prince of the Tang Dynasty, Li Chengqian, the reborn emperor of the Tang Dynasty, and Li Ke, the reborn emperor of the Tang Dynasty. These novels told the story of a modern otaku who transmigrated to the 17th year of Zhenguan in the Tang Dynasty and became the crown prince, Li Chengqian, as well as the plot of Li Chengqian's efforts to fight for the throne and deal with powerful officials and Turks. In addition, novels about Li Chengqian and Li Yunrui also existed, including " Celebrating Years: The Fox and the Dodder Flower,"" Celebrating Years: Light Beard and Eyebrows, Clouds Hide Wisdom,"" Celebrating Years: Passing Through Flowers," and " Celebrating Years: Daisies." These novels used Li Yunrui as the main character, telling the story and emotional experiences of his life in the world of celebration. However, the details of Li Chengqian's plot and development were unclear.
There were novels about Li Chengqian in the years of celebration, including "Celebrating Years: Fox and Dodder Flower,""Celebrating Years: Light Beard and Eyebrow, Clouds Hidden Rui,""Celebrating Years: Passing through Ten Thousand Flowers,""Celebrating Years: Daisy," etc. These novels used Li Yunrui as the main character, telling the story and emotional experiences of his life in the world of celebration. Among them," Celebrating Years: The Fox and the Dodder Flower " was written by a little green field, and the story of the book revolved around Li Yunrui. The plot and author information of the other novels were temporarily unknown. The details of Li Chengqian's plot and development were unclear.
Joy of Life did not have any clear information about Li Chengqian's novel. The search results mentioned that there were novels about Li Chengqian and Li Yunrui in Joy of Life, but they did not provide information about Li Chengqian's specific plot and story development. Therefore, the current search results did not provide any details about Joy of Life Li Chengqian's novel.
We can learn that there is an affair between the eldest princess Li Yunrui and the crown prince Li Chengqian in Joy of Life. Their affair was discovered through a young eunuch named Hong Zhu. Hong Zhu used the Qing Emperor's suspicious personality to expose their private affair to the Qing Emperor. Hong Zhu was originally from Yingzhou with the surname Chen. His family's mountain property had been taken away by the local Zhizhou. In order to survive, Hong Zhu entered the palace and became a eunuch. During one of his trips to fetch water, Hong Zhu met the old eunuch, Hong Sixiang, who fanned him to chase away the flies. The search results did not provide any more information about Li Yunrui and Li Chengqian's specific plot and development.
Some information about Li Yunrui and Li Chengqian's novels. They were the main characters in the novel "Celebrating Years", including "Celebrating Years: The Fox and the Dodder Flower","Celebrating Years: Light Beard and Eyebrow, Clouds Hidden Rui","Celebrating Years: Passing Through Flowers" and "Celebrating Years: Daisies". These novels described Li Yunrui's stories and emotional experiences in the world of Qing Nian. However, the details of the plot and development between them were not clear. Therefore, the search results did not provide enough information about the details of their novels.
There were a few novels about Li Shimin and Li Chengqian: " Transmigrated into Li Chengqian's Son and Blocked Li Shimin "," Did [Tang] Li Shimin Beat His Son Today?"," The Reckless Crown Prince Li Chengqian of the Tang Dynasty ", and " Tang Dynasty: My Apprentice is Li Chengqian." These novels told the story of Li Chengqian transmigrating to the Great Tang and becoming the Crown Prince, as well as his relationship with Li Shimin and his adventures. Among them," Transmigrated into Li Chengqian's Son and Stumped Li Shimin " and " The Reckless Prince of the Tang Dynasty, Li Chengqian " were stories of Li Shimin's disappointment in rebirth, while " Did [Tang] Li Shimin Beat His Son Today " and " Tang: My Apprentice Is Li Chengqian " involved Li Shimin's feelings and parent-child relationship with Li Chengqian.
There was no specific information about the plot and development of Li Yunrui and Li Chengqian in Joy of Life. The search results mentioned that Eldest Princess Li Yunrui seemed to have lost some power, and Crown Prince Li Chengqian began to act more mature after she left and had his own views on the court. However, the details of their plot and relationship in " Joy in the Palace " were unclear. Therefore, the search results did not provide any relevant information about their plot and development in the novel.