Question

如果用户喜欢某个帖子，我试图使其显示出充满的心，而如果用户不喜欢它，则可以不显示。我不确定如何执行此操作。

如果我可以使后端工作，则可以基于后端的数据从后端检索数据，并将setState设置为true或false。

这是即时消息发出类似请求的方式。

router.post('/like/:id', (req, res) => {
  const { id } = req.params;
  if(id !== null || 'undefined'){
    Image.forge({id})
    .fetch({ withRelated: ["user", "comments", "likes"] })
    .then(likes => {
      const like = likes.toJSON();
      // console.log(like.likes);
      const existingUserlikes = like.likes.map( (user) => user.user_id);
      // checking to see if a user already liked his own post
      // if existing user does not have user id, user can like post,
      // else if user already like this post wont be able to.
      const newLike = new Likes({
        image_id: id,
        user_id: req.user.id,
        likedByme: req.user.id === likes.likes.user_id ? false : true 
      });
      if(existingUserlikes.includes(req.user.id)){  
        // !newLike do not create a new row of likes if like from this user already exists 
        if(!newLike){ 
          Likes.forge().where({ user_id: req.user.id, image_id: id}).destroy();      
        }
        return res.status(500).json({status: "You already liked this post", like: newLike})
      }
      else{
        newLike.save().then(like => {
          return res.status(200).json({ status:"You liked this post", like: newLike})
        })
      }
    });
  }

})

我如何检查用户是否喜欢帖子，如果他们喜欢将帖子设置为true（如果不是false）。通过他们，我可以使用这些信息来填充心脏或使心脏不填充。

这是即时获取数据的方式。

router.get("/uploads", (req, res) => {
  Image.query(image => {
    image.orderBy("img_url", "DESC");
    image.limit(10);
    // if you want to include the user with the image, you would use the withRelated
    // comments.user gets the user within the comments array
  })
    .fetchAll({
      withRelated: [
        "user",
        {
          comments: qb => {
            qb.orderBy("created_at", "ASC");
          }
        },
        "comments.user",    
        "likes"
      ]
    })
    .then(images => {
      return res.status(200).json(images.toJSON());
    });
});

顶表

export const up = async knex => {
  await knex.schema.createTable("likes", t => {
    t.increments("id").primary().unsigned();
    t.integer("user_id").unsigned().references("id").inTable("users");
    t.integer("image_id").unsigned().references("id").inTable("images");
    t.string('likedByme').defaultTo(false);
    t.timestamp("created_at").defaultTo(knex.fn.now());
    t.timestamp("deleted_at").defaultTo(knex.fn.now());
    t.timestamp('restored_at').defaultTo(knex.fn.now());
    t.timestamp("updated_at").defaultTo(knex.fn.now());
  });
};

export const down = async knex => {
  await knex.schema.dropTable("likes");
};

如何查看用户是否喜欢帖子

0 个答案: