38 Matching Annotations
  1. Jun 2024
    1. to your point for 00:13:46 every problem there's going to be a solution and AI is going to have it and then for every solution for that there's going to be a new problem

      for - AI - progress trap - nice simple explanation of how progress traps propagate

  2. Jan 2024
    1. Instance methods Instances of Models are documents. Documents have many of their own built-in instance methods. We may also define our own custom document instance methods. // define a schema const animalSchema = new Schema({ name: String, type: String }, { // Assign a function to the "methods" object of our animalSchema through schema options. // By following this approach, there is no need to create a separate TS type to define the type of the instance functions. methods: { findSimilarTypes(cb) { return mongoose.model('Animal').find({ type: this.type }, cb); } } }); // Or, assign a function to the "methods" object of our animalSchema animalSchema.methods.findSimilarTypes = function(cb) { return mongoose.model('Animal').find({ type: this.type }, cb); }; Now all of our animal instances have a findSimilarTypes method available to them. const Animal = mongoose.model('Animal', animalSchema); const dog = new Animal({ type: 'dog' }); dog.findSimilarTypes((err, dogs) => { console.log(dogs); // woof }); Overwriting a default mongoose document method may lead to unpredictable results. See this for more details. The example above uses the Schema.methods object directly to save an instance method. You can also use the Schema.method() helper as described here. Do not declare methods using ES6 arrow functions (=>). Arrow functions explicitly prevent binding this, so your method will not have access to the document and the above examples will not work.

      Certainly! Let's break down the provided code snippets:

      1. What is it and why is it used?

      In Mongoose, a schema is a blueprint for defining the structure of documents within a collection. When you define a schema, you can also attach methods to it. These methods become instance methods, meaning they are available on the individual documents (instances) created from that schema.

      Instance methods are useful for encapsulating functionality related to a specific document or model instance. They allow you to define custom behavior that can be executed on a specific document. In the given example, the findSimilarTypes method is added to instances of the Animal model, making it easy to find other animals of the same type.

      2. Syntax:

      Using methods object directly in the schema options:

      javascript const animalSchema = new Schema( { name: String, type: String }, { methods: { findSimilarTypes(cb) { return mongoose.model('Animal').find({ type: this.type }, cb); } } } );

      Using methods object directly in the schema:

      javascript animalSchema.methods.findSimilarTypes = function(cb) { return mongoose.model('Animal').find({ type: this.type }, cb); };

      Using Schema.method() helper:

      javascript animalSchema.method('findSimilarTypes', function(cb) { return mongoose.model('Animal').find({ type: this.type }, cb); });

      3. Explanation in Simple Words with Examples:

      Why it's Used:

      Imagine you have a collection of animals in your database, and you want to find other animals of the same type. Instead of writing the same logic repeatedly, you can define a method that can be called on each animal instance to find similar types. This helps in keeping your code DRY (Don't Repeat Yourself) and makes it easier to maintain.

      Example:

      ```javascript const mongoose = require('mongoose'); const { Schema } = mongoose;

      // Define a schema with a custom instance method const animalSchema = new Schema({ name: String, type: String });

      // Add a custom instance method to find similar types animalSchema.methods.findSimilarTypes = function(cb) { return mongoose.model('Animal').find({ type: this.type }, cb); };

      // Create the Animal model using the schema const Animal = mongoose.model('Animal', animalSchema);

      // Create an instance of Animal const dog = new Animal({ type: 'dog', name: 'Buddy' });

      // Use the custom method to find similar types dog.findSimilarTypes((err, similarAnimals) => { console.log(similarAnimals); }); ```

      In this example, findSimilarTypes is a custom instance method added to the Animal schema. When you create an instance of the Animal model (e.g., a dog), you can then call findSimilarTypes on that instance to find other animals with the same type. The method uses the this.type property, which refers to the type of the current animal instance. This allows you to easily reuse the logic for finding similar types across different instances of the Animal model.

      Certainly! Let's go through each part and explain it in simple terms: ### 1. `this` in Mongoose: - **What is `this`?** In JavaScript, `this` refers to the current context or object. In Mongoose, particularly within methods and middleware functions, `this` represents the instance (document) the function is currently operating on. - **Why is it used?** `this` is used to access and modify the properties of the current document. For example, in a Mongoose method, `this` allows you to refer to the fields of the specific document the method is called on. ### 2. Example: Let's use the `userSchema.pre("save", ...)`, which is a Mongoose middleware, as an example: ```javascript userSchema.pre("save", async function (next) { if (!this.isModified("password")) { next(); } else { this.password = await bcrypt.hash(this.password, 10); next(); } }); ``` - **Explanation in Simple Words:** - Imagine you have a system where users can sign up and set their password. - Before saving a new user to the database, you want to ensure that the password is securely encrypted (hashed) using a library like `bcrypt`. - The `userSchema.pre("save", ...)` is a special function that runs automatically before saving a user to the database. - In this function: - `this.isModified("password")`: Checks if the password field of the current user has been changed. - If the password is not modified, it means the user is not updating their password, so it just moves on to the next operation (saving the user). - If the password is modified, it means a new password is set or the existing one is changed. In this case, it uses `bcrypt.hash` to encrypt (hash) the password before saving it to the database. - The use of `this` here is crucial because it allows you to refer to the specific user document that's being saved. It ensures that the correct password is hashed for the current user being processed. In summary, `this` in Mongoose is a way to refer to the current document or instance, and it's commonly used to access and modify the properties of that document, especially in middleware functions like the one demonstrated here for password encryption before saving to the database.

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  3. Nov 2022
    1. This occurs for the child processes, where the entry is still needed to allow the parent process to read its child's exit status: once the exit status is read via the wait system call, the zombie's entry is removed from the process table and it is said to be "reaped".
  4. Sep 2022
    1. This means that when considering the "unevaluatedProperties": false in the root schema, "wheels" has not been evaluated, so unevaluatedProperties applies to it, and therefore validation fails because the false subschema fails by definition against any instance.
  5. Apr 2022
    1. Think the mere existence of a file is effectively like writing a require call for them, which is executed on demand (autoload) or upfront (eager load).
  6. Jan 2022
    1. FORBIDDEN: Status code (403) indicating the server understood the request but refused to fulfill it. User/agent known by the server but has insufficient credentials. Repeating request will not work, unless credentials changed, which is very unlikely in a short time span.
    2. There's a problem with 401 Unauthorized, the HTTP status code for authentication errors. And that’s just it: it’s for authentication, not authorization. Receiving a 401 response is the server telling you, “you aren’t authenticated–either not authenticated at all or authenticated incorrectly–but please reauthenticate and try again.” To help you out, it will always include a WWW-Authenticate header that describes how to authenticate.
    3. So, for authorization I use the 403 Forbidden response. It’s permanent, it’s tied to my application logic, and it’s a more concrete response than a 401. Receiving a 403 response is the server telling you, “I’m sorry. I know who you are–I believe who you say you are–but you just don’t have permission to access this resource. Maybe if you ask the system administrator nicely, you’ll get permission. But please don’t bother me again until your predicament changes.”
    4. UNAUTHORIZED: Status code (401) indicating that the request requires authentication, usually this means user needs to be logged-in (session). User/agent unknown by the server. Can repeat with other credentials. NOTE: This is confusing as this should have been named 'unauthenticated' instead of 'unauthorized'.
    5. +----------------------- | RESOURCE EXISTS ? (if private it is often checked AFTER auth check) +----------------------- | | NO | v YES v +----------------------- 404 | IS LOGGED-IN ? (authenticated, aka user session) or +----------------------- 401 | | 403 NO | | YES 3xx v v 401 +----------------------- (404 no reveal) | CAN ACCESS RESOURCE ? (permission, authorized, ...) or +----------------------- redirect | | to login NO | | YES | | v v 403 OK 200, redirect, ... (or 404: no reveal) (or 404: resource does not exist if private) (or 3xx: redirection)
    1. When you initially logon with OAuth2, you will be redirect to Google’s sign-in page,. Once you have signed in, Google issues you a special OAuth2 token which is saved in Thunderbird and can be seen in the same place as passwords. So when you next logon to gmail, it is using that unique OAuth ID instead of password.
  7. Nov 2021
    1. In your Svelte component, you can then use your store with the special $ prefix syntax, to access the value of the store ('cause the temperature variable is a reference to the store itself, it's just a mean to our end, the result we need is the value):
    2. Stores are essentially some kind of simplified streams (or Observable as they're called in ES), that is they represent a value over time.
    3. Stores are the idiomatic Svelte way when you need to import "reactivity" from your normal JS sources.
  8. Aug 2021
    1. function strictIsDog<T extends Dog extends T ? unknown : never>( // like <T super Dog> candidate: Dog | T // if Dog extends T then Dog | T is T ): candidate is Dog { // compiler recognizes that Dog | T can narrow to T return "bark" in candidate; } if (strictIsDog(animal)) {} // okay if (strictIsDog(dog)) {} // okay if (strictIsDog(mixed)) {} // okay if (strictIsDog(cat)) {} // error! // ~~~ <-- Cat is not assignable to Dog
  9. Apr 2021
    1. It's simple really ... put tests into a shared example that you want multiple things to conform to. Put code into a shared context that you need to include in multiple tests.
  10. Mar 2021
    1. Intuitively, a subcategory of C is a category obtained from C by "removing" some of its objects and arrows.
  11. Feb 2021
    1. A Monad wraps a value or a computation with a particular context. A monad must define both a means of wrapping normal values in the context, and a way of combining computations within the context.
    1. All those names of things - topology, complex analysis, and differential geometry - might not sound like much to you now, but you'll soon learn that they're really just describing the shapes of things in our Universe, and the way those shapes change in time and space are explained by things like calculus and chaos theory.
  12. Jan 2021
  13. Nov 2020
    1. So let's say we pull down evil/foo which is FROM ubuntu followed by RUN apt-get update except with a small surprise included in the image. Subsequent builds using those same commands will be compromised.
  14. Oct 2020
    1. Not all application state belongs inside your application's component hierarchy. Sometimes, you'll have values that need to be accessed by multiple unrelated components, or by a regular JavaScript module.
    2. A store is simply an object with a subscribe method that allows interested parties to be notified whenever the store value changes. In App.svelte, count is a store, and we're setting count_value in the count.subscribe callback.
    1. Just like elements can have children... <div> <p>I'm a child of the div</p> </div>...so can components. Before a component can accept children, though, it needs to know where to put them. We do this with the <slot> element.
  15. Sep 2020
  16. May 2020
    1. whose personal data you collect and process as “controller” (that is the word that GDPR uses for whoever determines the purposes and means of the processing of personal data).
  17. Mar 2020
    1. First-party cookies are the lifeblood of every website, enabling businesses to remember key pieces of information about users and to collect analytics data. Third-party cookies are the bread and butter of AdTech, allowing publishers to monetize their websites, and brands to run advertising and marketing campaigns.