Post

A post is used for forum that is under a category, that has title, content, comments created by users.

Post Model

Fields

• DatabaseReference ref;
  • DatabaseReference
  • Reference in RTDB to access the post
• id
  • String
  • The ID of the category
• title
  • String
  • The title of the post
• content
  • String
  • The actual content of the post
• category
  • String
  • The category where the post belongs.
• uid
  • String
  • The ID of the User who posted it.
• createdAt
  • DateTime
  • When was the post created.
  • In RTDB it is saved as int, milliseconds since epoch.
• order
  • int
  • This is negated createdAt.
  • It is being used to sort the posts since RTDB doesen't have descending order yet.
• likes
  • List of String
  • The uid's of user who liked the post.
• urls;
  • List of String
  • urls of the attached files (mostly for photos)
• noOfLikes
  • int
  • The number of Likers
• noOfComments
  • int
  • The number of comments
  • This is save only under '/posts-summary'. This is not saved under '/posts'.
• deleted
  • bool
  • Whether the comment is deleted. True means deleted. Otherwise, not deleted.

onPostCreate, onPostUpdate, onPostDelete

To add custom code upon creating, updating or deleting the post, you may set onPostCreate, onPostUpdate and onPostDelete in the ForumService.instance.init() at the app start.

The custom codes will be ran after the event.

Initializing

Check the example code below to understand how to set these onPostCreate, onPostUpdate, and onPostDelete. Put initialize recommendedly on initialization in main.

initForum() {
    ForumService.instance.init(
        onPostCreate: (PostModel post) => toast("Created post: $post"),
        onPostUpdate: (PostModel post) => toast("Updated post: $post"),
        onPostDelete: (PostModel post) => toast("Deleted post: $post"),
        // ... 
    );
}

Viewing a post

You can use the ForumService to View the Post in a screen.

final post = PostModel(
  // get the post
);

ForumService.instance.showPostViewScreen(
  context,
  post: post,
);

It uses Fireship's PostViewScreen widget. This is the default screen widget to view post.

For customization, modify the code below.

final post = PostModel(
  // get the post
);

await showGeneralDialog(
  context: context,
  pageBuilder: ($, $$, $$$) => PostViewScreen(
    post: post,
  ),
);

Posts Listing

The PostListTile widget can be used as List Tile. Show a list of posts like the code below.

FirebaseDatabaseListView(
  query: Ref.postsSummary.child(category).orderByChild(Field.order),
  itemBuilder: (context, snapshot) {
    return PostListTile(
      post: PostModel.fromSnapshot(snapshot),
    );
  },
);

Replace the PostListTile widget as needed (like customization).

Post Creation Logic

• Post will be creatd with the following data. There is no category or post id.

  • uid (required)
  • title (optional)
  • content (optinal)
  • urls (optional)
  • createdAt (required)
  • order (required)

• Right after creation of the post, it will update the post with new order. So, if you are working on cloud functions with event trigger, don't be supprised that it may cause multiple write events.

• When a post is created, the counter part summary record will be created under /posts-summary with the following fields.

  • content
  • createdAt
  • order
  • title
  • uid
  • url