”工欲善其事,必先利其器。“—孔子《论语.录灵公》
首页 > 编程 > 让我解释一下 ThingsDB Todo 应用程序演示

让我解释一下 ThingsDB Todo 应用程序演示

发布于2024-08-28
浏览:107

Some time ago I've discovered a database called ThingsDB. I was curious about it and I did some reading. I've discovered they support TCP connectivity but they didn't have driver for some specific platforms therefore I've developed a driver for it for javascript and for php.

When I worked on javascript driver I've realized, it would be possible to use ThingsDB directly from frontend without any backend or middleware. You can open websocket (TCP) connection from browser, so I reached out to the authors of ThingsDB and they added support for websocket (available from ThingsDB version 1.6). This way my javascript driver can be used from frontend (browser) and also from javascript based backend (ex. node.js). I wrote article here about my php driver where I have received interesting feedback. People wanted to see more of the potential of ThingsDB. Based on that I chose not to write article about my javascript driver right after I've finished it, but I've decided it would be best to make demo.

To understand basics of ThingsDB and this demo I suggest you to read continuosly as I explain specific features on the way. I expect you are familiar with programming in general, at least basics. And maybe some javascript and jQuery.

If you want to follow this article by executing code snippets inside of ThingsDB, you have to use attached docker file mentioned in Installation guide.


ThingsDB structure introduction

First things first. Let me shortly explain the structure.

ThingsDB contains collections. Collection contains data, procedures, tasks, data types and enums. There is also prior collection (scope) @thingsdb which contains user access accounts and it can also contains procedures and tasks. Lastly there is @node scope which is not important right now.

  • Data - persistent stored data
  • Procedure - like function, can have arguments and it can return value
  • Tasks - planned events, like cron
  • Data types - like classes, it can have properties and methods
  • Enums - enumerators

All named things like data, procedures, tasks, data types and enums are defined by developers implementing ThingsDB. New instance of this database only contains empty collection called @:stuff and user account admin. I use this collection as main one for this demo.

Talking to yourself

When you execute query or run procedure on ThingsDB, you have to specify on which collection it will run. That can be sometimes limiting and if you have a need to execute query or run procedure on another collection, there is a way how to achieve that. There is a module called thingsdb (book, GitHub) which allows you to access another collection from collection as specific user. My demo use this feature heavily when dealing with user accounts which is reason I mention it here. I have installed this module as explained in manual.

I'll explain permissions little bit later but fyi: User account I've made for this module has permissions Query, Change, Grant on collection @thingsdb and Change, Grant on collection @:stuff.

User accounts

I chose to use only ThingsDB and that means I had to use their user accounts. I had to deal with registration and login which was little bit tricky because of the absence of backend. Of course I could use some third party authentification server (auth0, etc.), but I didn't want to rely on anything else.

In the case somebody wants to implement 3rd party auth system, you can do HTTP requests from ThingsDB with Request module (book, GitHub).

To allow users to register I needed some user account to communicate with ThingsDB and execute the registration. But required credentials for this account would be published in javascript code which doesn't sound very secure. I didn't want to deal with all security problems but I wanted to implement at least the simple ones. ThingsDB support granting permissions for each user account against each collection specifically. Available permissions to grant are Query, Change, Grant, Join and Run.

  • Query - query ThingsDB
  • Change - allow execution of code which does change of data
  • Grant - allow granting permissions
  • Join - allow join rooms
  • Run - run stored procedure

I'm not able to use Query at all. Because with this command you can execute anything on ThingsDB and opening this to the client browser pose huge security problem. The path was clear, I had to use procedures and just allow Run for client.

Important information to know is the user accounts doesn't have only password but also access tokens (with expiration if needed).

Prepare ThingsDB for registration

I've created collection @:auth and user account with name aa (auth account) and I gave him permission Run over this collection. Collection @:auth contains only one procedure called register. All this means, the user aa can do only one thing which is to run procedure called register. Therefore his access token can be published.

Procedure register does create new account and grant required permissions. The code looks like this:

new_procedure('register', |email, password| {
    if (email.len() == 0 || password.len() == 0 || !is_email(email)) {
        raise('required values not provided');
    };
    thingsdb.query('@t', "
 if (has_user(email)) {
     raise('email already registered');
 };
 new_user(email);
 set_password(email, password);
 grant('@:stuff', email, RUN | CHANGE);
 ", {
        email:,
        password:,
    });
    nil;
});

I guess this is your first time seeing code from ThingsDB. It is familiar to another programming languages just with slight changes. What the procedure does:

  • Accepts two arguments
  • Verify arguments email and password
  • Use module thingsdb explained in section Talking to yourself to run query
    • Check if email is already registered
    • Create new user account and set password
    • Grant required permissions

email:, can be a little bit confusing but it's a shorthand when you want to pass variable to argument and argument and variable has the same name.

@t is shortcut for @thingsdb scope.

Frontend implemention of registration

With everything ready at ThingsDB side I've created simple website with registration form and few lines of javascript. The code snippet which manages to run procedure inside of ThingsDB looks like this:

const thingsdb = new ThingsDB();
thingsdb.connect()
  .then(() => thingsdb.authToken(localStorage.getItem('aa')))
  .then(() => thingsdb.run('@:auth', 'register', [
    $('#email').val(), 
    $('#password1').val()
  ]))
  1. It performs authentification with token (for aa user account)
  2. Runs procedure register

I keep access token of user aa in browser localStorage.

To see whole implementation look here:

  • register.html
  • register.js

Login

After user is able to register, next step was to implement login action. For login password is required but it would be not very safe to store user password in browser. The solution is to generate access token (with expiration) after login and return it to client, where it can be stored in browser (ex. sessionStorage). So I've created procedure in @:stuff collection where registered user account has required permissions.

new_procedure('login', || {
    email = user_info().load().name;
    if (is_email(email)) {
        thingsdb.query('@t', "new_token(email, datetime().move('days', 1));", {email: })
            .then(|token| token);
    };
});

Creation of token has to be called on @thingsdb scope, in that case I use thingsdb module again. The javascript code snippet to call this procedure looks like this:

const thingsdb = new ThingsDB();
thingsdb.connect()
  .then(() => thingsdb.auth($('#email').val(), $('#password').val()))
  .then(() => thingsdb.run('@:stuff', 'login'))
  .then(token => {
    sessionStorage.setItem('token', token);
    window.location.href = './overview.html';
  })

Obtained access token is stored in sessionStorage.

Here you can check whole login page which contains login form and required javascript code:

  • index.html
  • index.js

Overview

After login user is redictered here where he has some account actions and list of his Todos. That required to specify structure, how Todo data will be stored and for this purpose we can use data types. I created Todo type which has name, user_id and items. Item type has description, checked status and Todo reference. Connection between Todo and Item is made with both ways relation (book, docs). Both types are defined in @:stuff collection.

new_type('Item');
new_type('Todo');

set_type('Item', {
    description: "'str',"
    checked: 'bool',
    todo: 'Todo?',
});
set_type('Todo', {
    name: 'str',
    items: '{Item}',
    user_id: 'int',
});

mod_type('Item', 'rel', 'todo', 'items');

In this piece of code you can see how the types are made, what properties with data types does they have and set up of relation between them.

But this is just definition. We need to store Todos somewhere. For that we create property directly on collection @:stuff like this. Without the dot it would be just variable and it won't be persistent.

.todos = set();

Now after the data structure is ready, let's go through each action.

Todos

Upon loading of overview page, request to load Todos of users to ThingsDB is made. First we need a procedure on @:stuff collection which returns list of Todos:

new_procedure('list_todos', || {
    user_id = user_info().load().user_id;
    .todos.filter(|t| t.user_id == user_id);
});

Filter is function available to call on set.

Now we can call this procedure with javascript code snippet like this (processing received data is omitted):

const thingsdb = new ThingsDB();
thingsdb.connect()
  .then(() => thingsdb.authToken(sessionStorage.getItem('token')))
  .then(() => thingsdb.run('@:stuff', 'list_todos'))
  .then(todos => { })

You can check the whole implementation here:

  • overview.html
  • overview.js

Password change

For this action I've created procedure update_password which requires to use thingsdb module again. User accounts are stored in @thingsdb scope.

new_procedure('update_password', |password| {
    email = user_info().load().name;
    if (is_email(email)) {
        thingsdb.query('@t', 'set_password(email, password);', {
            email:,
            password:,
        });
    };
});

I use html dialog tag to enter a new password and the javascript code snippet to handle it is very simple:

thingsdb.run('@:stuff', 'update_password', [$('#password1').val()])

I don't have to call authToken again because websocket connection is still open from the request to load Todos.

You can check the whole implementation here:

  • overview.html
  • overview.js

Delete account

Procedure for this action removes not only user account but also his Todos. It looks like this:

new_procedure('delete_user', || {
    email = user_info().load().name;
    if (is_email(email)) {
        .todos.remove(|todo| todo.user_id == user_id);
        thingsdb.query('@t', 'del_user(email);', {email: });
    };
});

Remove is another function which can be called on set.

I had to use thingsdb module again. User accounts are stored in @thingsdb scope.

Call of this procedure can be done easily with javascript code snippet:

thingsdb.run('@:stuff', 'delete_user')

I don't have to call authToken again because websocket connection is still open from the request to load Todos.

Look at the whole implementation here:

  • overview.html
  • overview.js

Create Todo

User need a way to create new Todo. For that reason I made page new_todo and overview contains link to it. Form to create todo consist of todo name and items (descriptions). I decided to store new Todo with items in two steps, because originally I wanted to allow editing of Todo (which in the end didn't happen). Therefore I've created two new procedures.

new_procedure('create_todo', |name| {
    t = Todo{
        name:,
        user_id: user_info().load().user_id,
    };
    .todos.add(t);
    t.id();
});

new_procedure('add_todo_items', |todo_id, items| {
    todo = thing(todo_id);
    if (todo.user_id != user_info().load().user_id) {
        raise('Not yours');
    };
    todo.items.clear();
    items.each(|i| {
        item = Item{
            checked: false,
            description: "i,"
        };
        todo.items.add(item);
    });
});

First procedure to create todo returns it's id and second procedure deletes all items and adds new ones. I think if you read until here you are already getting hang of it and I don't have to explain .todos.add() or items.each() (set add, thing each).

What is new here is thing(todo_id). You can get reference to any thing (thing is like instance of class/data type) from collection by id. You don't have to know where is stored, you can just get it. Thing has assigned id when is stored persistently.

To perform defined action you just have to call it with javascript code snippet:

thingsdb.run('@:stuff', 'create_todo', [$('#name').val()])
  .then((todo) => thingsdb.run('@:stuff', 'add_todo_items', [
    todo, items.length ? items.map(function () {
      return $(this).val();
    }).get() : []
  ]))

Look at the whole implementation here:

  • new_todo.html
  • new_todo.js

Todo detail

Overview page shows list of user Todos. By clicking on it user is redirected to page where he can see Todo items, change their status and delete whole Todo list.

Load Todo data

To load one specific Todo I've created new procedure:

new_procedure('list_todo', |todo_id| {
    todo = thing(todo_id);
    if (todo.user_id != user_info().load().user_id) {
        raise('Not yours');
    };
    return todo, 2;
});

Now you are propably asking why there is return todo, 2;? With return you can set depth of data you want to return. With number 2 here returned data contains not only Todo itself, but also Items the Todo has relation with.

Because Todo id is passed as uri get parameter, the javascript code snippet to call this procedure looks like this:

thingsdb.run('@:stuff', 'list_todo', [
  parseInt(location.search.match(/id=(\d )/)[1])
])

Look at the whole implementation here:
todo.html
todo.js

Change Todo item status

I render todo items as checklist, so to change status of item I've created new procedure:

new_procedure('mark_item', |item_id, checked| {
    item = thing(item_id);
    if (item.todo.user_id != user_info().load().user_id) {
        raise('Not yours');
    };
    item.checked = checked;
    nil;
});

Because you can also uncheck, not only check item, javascript code snippet has to be like this:

thingsdb.run('@:stuff', 'mark_item', [
  parseInt(this.id),
  $(this).is(':checked')
])

Look at the whole implementation here:
todo.html
todo.js

Delete Todo

If we want to delete Todo, we don't have to delete items because they are not stored separately. If Todo is removed, no other reference exists for its items and they are automatically removed.

new_procedure('delete_todo', |todo_id| {
    todo = thing(todo_id);
    if (todo.user_id != user_info().load().user_id) {
        raise('Not yours');
    };
    .todos.remove(todo);
});

Now the javascript code snippet is simple:

thingsdb.run('@:stuff', 'delete_todo', [
  parseInt(location.search.match(/id=(\d )/)[1])
])

Look at the whole implementation here:
todo.html
todo.js

Installation guide

To simplify usage of this demo you can run ThingsDB in docker with Dockerfile. At the end of this file you find required commands as comments. Instance of ThingsDB made with this Dockerfile is based on specific branch which was not yet released and introduces using user_info() inside of collections.

Next simply open install.html which creates everything required in this ThingsDB instance and store access token of aa user to localStorage.


That's it. I hope I gave you basic insight into this technology. If you like my work you can buy me a tea.

Let me explain a ThingsDB Todo app demo

No AI was used to generate this content, only the cover picture.

版本声明 本文转载于:https://dev.to/stefanak-michal/let-me-explain-a-thingsdb-todo-app-demo-2n9g?1如有侵犯,请联系[email protected]删除
最新教程 更多>
  • 图片在Chrome中为何仍有边框?`border: none;`无效解决方案
    图片在Chrome中为何仍有边框?`border: none;`无效解决方案
    在chrome 在使用Chrome and IE9中的图像时遇到的一个频繁的问题是围绕图像的持续薄薄边框,尽管指定了图像,尽管指定了;和“边境:无;”在CSS中。要解决此问题,请考虑以下方法: Chrome具有忽略“ border:none; none;”的已知错误,风格。要解决此问题,请使用以下...
    编程 发布于2025-06-27
  • Python读取CSV文件UnicodeDecodeError终极解决方法
    Python读取CSV文件UnicodeDecodeError终极解决方法
    在试图使用已内置的CSV模块读取Python中时,CSV文件中的Unicode Decode Decode Decode Decode decode Error读取,您可能会遇到错误的错误:无法解码字节 在位置2-3中:截断\ uxxxxxxxx逃脱当CSV文件包含特殊字符或Unicode的路径逃...
    编程 发布于2025-06-27
  • Java的Map.Entry和SimpleEntry如何简化键值对管理?
    Java的Map.Entry和SimpleEntry如何简化键值对管理?
    A Comprehensive Collection for Value Pairs: Introducing Java's Map.Entry and SimpleEntryIn Java, when defining a collection where each element com...
    编程 发布于2025-06-27
  • 如何使用Python的请求和假用户代理绕过网站块?
    如何使用Python的请求和假用户代理绕过网站块?
    如何使用Python的请求模拟浏览器行为,以及伪造的用户代理提供了一个用户 - 代理标头一个有效方法是提供有效的用户式header,以提供有效的用户 - 设置,该标题可以通过browser和Acterner Systems the equestersystermery和操作系统。通过模仿像Chro...
    编程 发布于2025-06-27
  • 为什么不````''{margin:0; }`始终删除CSS中的最高边距?
    为什么不````''{margin:0; }`始终删除CSS中的最高边距?
    在CSS 问题:不正确的代码: 全球范围将所有余量重置为零,如提供的代码所建议的,可能会导致意外的副作用。解决特定的保证金问题是更建议的。 例如,在提供的示例中,将以下代码添加到CSS中,将解决余量问题: body H1 { 保证金顶:-40px; } 此方法更精确,避免了由全局保证金重置引...
    编程 发布于2025-06-27
  • 为什么PHP的DateTime :: Modify('+1个月')会产生意外的结果?
    为什么PHP的DateTime :: Modify('+1个月')会产生意外的结果?
    使用php dateTime修改月份:发现预期的行为在使用PHP的DateTime类时,添加或减去几个月可能并不总是会产生预期的结果。正如文档所警告的那样,“当心”这些操作的“不像看起来那样直观。 ; $ date->修改('1个月'); //前进1个月 echo $ date->...
    编程 发布于2025-06-27
  • 如何克服PHP的功能重新定义限制?
    如何克服PHP的功能重新定义限制?
    克服PHP的函数重新定义限制在PHP中,多次定义一个相同名称的函数是一个no-no。尝试这样做,如提供的代码段所示,将导致可怕的“不能重新列出”错误。 但是,PHP工具腰带中有一个隐藏的宝石:runkit扩展。它使您能够灵活地重新定义函数。 runkit_function_renction_re...
    编程 发布于2025-06-27
  • Java中如何使用观察者模式实现自定义事件?
    Java中如何使用观察者模式实现自定义事件?
    在Java 中创建自定义事件的自定义事件在许多编程场景中都是无关紧要的,使组件能够基于特定的触发器相互通信。本文旨在解决以下内容:问题语句我们如何在Java中实现自定义事件以促进基于特定事件的对象之间的交互,定义了管理订阅者的类界面。以下代码片段演示了如何使用观察者模式创建自定义事件: args)...
    编程 发布于2025-06-27
  • 同实例无需转储复制MySQL数据库方法
    同实例无需转储复制MySQL数据库方法
    在同一实例上复制一个MySQL数据库而无需转储在同一mySQL实例上复制数据库,而无需创建InterMediate sqql script。以下方法为传统的转储和IMPORT过程提供了更简单的替代方法。 直接管道数据 MySQL手动概述了一种允许将mysqldump直接输出到MySQL clie...
    编程 发布于2025-06-27
  • C++中如何将独占指针作为函数或构造函数参数传递?
    C++中如何将独占指针作为函数或构造函数参数传递?
    在构造函数和函数中将唯一的指数管理为参数 unique pointers( unique_ptr [2启示。通过值: base(std :: simelor_ptr n) :next(std :: move(n)){} 此方法将唯一指针的所有权转移到函数/对象。指针的内容被移至功能中,在操作...
    编程 发布于2025-06-27
  • 如何在Java字符串中有效替换多个子字符串?
    如何在Java字符串中有效替换多个子字符串?
    在java 中有效地替换多个substring,需要在需要替换一个字符串中的多个substring的情况下,很容易求助于重复应用字符串的刺激力量。 However, this can be inefficient for large strings or when working with nu...
    编程 发布于2025-06-27
  • 在JavaScript中如何并发运行异步操作并正确处理错误?
    在JavaScript中如何并发运行异步操作并正确处理错误?
    同意操作execution 在执行asynchronous操作时,相关的代码段落会遇到一个问题,当执行asynchronous操作:此实现在启动下一个操作之前依次等待每个操作的完成。要启用并发执行,需要进行修改的方法。 第一个解决方案试图通过获得每个操作的承诺来解决此问题,然后单独等待它们: co...
    编程 发布于2025-06-27
  • 您如何在Laravel Blade模板中定义变量?
    您如何在Laravel Blade模板中定义变量?
    在Laravel Blade模板中使用Elegance 在blade模板中如何分配变量对于存储以后使用的数据至关重要。在使用“ {{}}”分配变量的同时,它可能并不总是最优雅的解决方案。幸运的是,Blade通过@php Directive提供了更优雅的方法: $ old_section =“...
    编程 发布于2025-06-27
  • PHP阵列键值异常:了解07和08的好奇情况
    PHP阵列键值异常:了解07和08的好奇情况
    PHP数组键值问题,使用07&08 在给定数月的数组中,键值07和08呈现令人困惑的行为时,就会出现一个不寻常的问题。运行print_r($月)返回意外结果:键“ 07”丢失,而键“ 08”分配给了9月的值。此问题源于PHP对领先零的解释。当一个数字带有0(例如07或08)的前缀时,PHP将其...
    编程 发布于2025-06-27

免责声明: 提供的所有资源部分来自互联网,如果有侵犯您的版权或其他权益,请说明详细缘由并提供版权或权益证明然后发到邮箱:[email protected] 我们会第一时间内为您处理。

Copyright© 2022 湘ICP备2022001581号-3