26 Matching Annotations
  1. 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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  2. Dec 2023
    1. I disagree. What is expressed is an attempt to solve X by making something that should maybe be agnostic of time asynchronous. The problem is related to design: time taints code. You have a choice: either you make the surface area of async code grow and grow or you treat it as impure code and you lift pure synchronous logic in an async context. Without more information on the surrounding algorithm, we don't know if the design decision to make SymbolTable async was the best decision and we can't propose an alternative. This question was handled superficially and carelessly by the community.

      superficially and carelessly?

  3. Nov 2023
  4. Jun 2023
  5. Sep 2022
    1. When we do release a final version of JSON Schema, please do not use JSON Schema to guarantee an OpenAPI document is valid. It cannot do that. There are numerous constraints in the written specification that cannot be expressed in JSON Schema.
  6. Mar 2022
    1. I believe this is partly due to a militant position on free software. Some advocates believe so strongly that users should be able to recompile their software that they force them to do so. They break libraries seemingly on purpose just to say, “Recompile! Oh you can’t? That’ll teach you to use binary software!” Of course users don’t want to recompile their software, but what users actually want is usually lost on GNOME developers.
    1. Note that this is a breaking API change in the libraries (more information in the README.md). It does not affect the backwards compatibility of the protocol itself.

      annotation meta: may need new tag: backwards compatibility of the protocol backwards compatibility for [libraries that use [it?]]

  7. Sep 2021
  8. Aug 2021
    1. 3. The no-keyword-arguments syntax (**nil) is introduced You can use **nil in a method definition to explicitly mark the method accepts no keyword arguments. Calling such methods with keyword arguments will result in an ArgumentError. (This is actually a new feature, not an incompatibility)
  9. Jun 2021
    1. Users who have installed it decided to trust me, and I'm not comfortable transferring that trust to someone else on their behalf. However, if you'd like to fork it, feel free.

      Interesting decision... Seems like the project could have been handed off to new maintainers instead of just a dead-end abandoned project and little chance of anyone using it for new projects now.

      Sure you can fork it, but without a clear indication of which of the many forks in the network graph to trust, I doubt few will take the (massively) extra time to evaluate all options and choose an existing fork as a "leader" (or create their own fork) to go with continuing maintenance...

  10. Apr 2021
    1. There's nothing to stop you from doing initializer code in a file that lives in app/models. for example class MyClass def self.run_me_when_the_class_is_loaded end end MyClass.run_me_when_the_class_is_loaded MyClass.run_me... will run when the class is loaded .... which is what we want, right? Not sure if its the Rails way.... but its extremely straightforward, and does not depend on the shifting winds of Rails.

      does not depend on the shifting winds of Rails.

  11. Mar 2021
  12. Feb 2021
    1. note that TRB source code modifications are not proprietary

      In other words, you can build on this software in your proprietary software but can't change the Trailblazer source unless you're willing to contribute it back.

      loophole: I wonder if this will actually just push people to move their code -- which at the core is/would be a direction modification to the source code - out to a separate module. That's so easy to do with Ruby, so this restriction hardly seems like it would have any effect on encouraging contributions.

  13. Oct 2020
  14. Apr 2020
    1. Any critique of the digital must rec-ognize how precarity is differentially distributed across gender, race, and class

      I'm pretty sure this is already happening. It's just not called precarity - but the social inequities have long been studied.

  15. Nov 2019
    1. the main reason we built a new multiprocess architecture is that Chromium's multiprocess support was never contributed to the WebKit project. It has always lived in the separate Chromium tree, making it pretty hard to use for non-Chrome purposes.Before we wrote a single line of what would become WebKit2 we directly asked Google folks if they would be willing to contribute their multiprocess support back to WebKit, so that we could build on it. They said no.
  16. Jan 2019
    1. new subjects of knowledge

      Melvil Dewey: "Guess I'll forget the base 10 number system and switch to hexadecimal."

      For real, she's proposing developing knowledge that is outside of Dewey's ordering system. It's like 150 years old; it's about time!

  17. Sep 2018
  18. Feb 2018