Xara

A template and category Microservice

Environment Variables

To run this project, you will need to add the following environment variables to your .env file

look at the example in .env.example

DATABASE_URL

NODE_ENV

Run Locally

Clone the project

  git clone https://github.com/faithfulojebiyi/xara-microservice.git

Go to the project directory

  cd my-project

Install dependencies

  npm install

Start the dev server

  npm run dev

Running Tests

To run tests, run the following command

  npm test

API Reference

Create category

  POST /api/v1/category/create

Request Body Data	Type	Description
displayName	string	Required. Name of the category
categoryId	string	Default Null The category to be added to

Move category

  PATCH /api/v1/category/move/:id

Parameter	Type	Description
id	string	Required. Id of the category to be moved

Request Body Data	Type	Description
toCategoryId	string	Required. The id of the category to move to

Delete category

  DELETE /api/v1/category/:id

Parameter	Type	Description
id	string	Required. Id of category to be deleted

Create template

  POST /api/v1/template/create

Request Body Data	Type	Description
displayName	string	Required. Name of the template
categoryId	string	Default Null The category to be added to

Documentation Reference

Models

Categories

const categorySchema = new mongoose.Schema({
  displayName: {
    type: String,
    required: true,
    trim: true,
    unique: true
  },
  categoryId: {
    type: mongoose.Schema.ObjectId,
    ref: 'Category'
  },
  ancestorsIds: [
    {
      type: mongoose.Schema.ObjectId,
      ref: 'Category'
    }
  ]
})

• The categoryId is the direct parent category id. If the category is an Alpha category that is does not have a parent category the categoryId is null

• The ancestorsIds contains the ids of all the parent categories. If the category is an Alpha category that is does not have a parent category the ancestorsIds is an empty array []

Templates

const templateSchema = new mongoose.Schema({
  displayName: {
    type: String,
    required: true,
    trim: true
  },
  categoryId: {
    type: mongoose.Schema.ObjectId,
    ref: 'Category'
  },
  ancestorsIds: [
    {
      type: mongoose.Schema.ObjectId,
      ref: 'Category'
    }
  ]
})

• The categoryId is the direct parent category id. If the template is an Alpha template that is does not have a parent category the categoryId is null

• The ancestorsIds contains the ids of all the parent categories. If the template is an Alpha template that is it does not have a parent category the ancestorsIds is an empty array []

ACID

Using Transctions to make sure write operations are atomic. Most importantly when moving a category or deleting a category we have to make sure the subCategories and template reflect the changes.

Move Category

static async moveCategoryToNewCategory (req, res, next) {
  const session = await db.startSession()
  session.startTransaction()
  try {
    const queryTemplate1 = await Template.updateMany({
      $and: [
        { ancestorsIds: { $all: [req.category.categoryId, req.category._id] } },
        { categoryId: { $ne: req.category.categoryId } }
      ]
    },
    { $push: { ancestorsIds: req.body.toCategoryId } }
    )
    const queryTemplate2 = await Template.updateMany({
      $and: [
        { ancestorsIds: { $all: [req.category.categoryId, req.category._id] } },
        { categoryId: { $ne: req.category.categoryId } }
      ]
    },
    { $pullAll: { ancestorsIds: [req.category.categoryId] } }
    )
    const queryCategory1 = await Category.updateMany(
      { ancestorsIds: { $all: [req.category.categoryId, req.category._id] } },
      { $push: { ancestorsIds: req.body.toCategoryId } }
    )
    const queryCategory2 = await Category.updateMany(
      { ancestorsIds: { $all: [req.category.categoryId, req.category._id] } },
      { $pullAll: { ancestorsIds: [req.category.categoryId] } }
    )
    const queryCategory3 = await Category.updateOne(
      { _id: req.category._id },
      { $set: { categoryId: req.body.toCategoryId }, $push: { ancestorsIds: req.body.toCategoryId } }
    )
    const queryCategory4 = await Category.updateOne(
      { _id: req.category._id },
      { $pullAll: { ancestorsIds: [req.category.categoryId] } }
    )

    session.commitTransaction()
    return successResponse(res, {
      message: UPDATE_CATEGORY_SUCCESS,
      data: {
        queryTemplate1,
        queryTemplate2,
        queryCategory1,
        queryCategory2,
        queryCategory3,
        queryCategory4
      }
    })
  } catch (e) {
    session.abortTransaction()
    const dbError = new DBError({
      status: UPDATE_CATEGORY_ERROR,
      message: e.message
    })
    moduleErrLogMessager(dbError)
    next(new ApiError({ message: UPDATE_CATEGORY_ERROR }))
  } finally {
    session.endSession()
  }
}

req.category.categoryId this is the parent category id the current category belongs to Also known as the category to be moved from

req.body.toCategoryId this is category to be moved to and should now become the new categoryId of the category we want to move

Delete Category

static async deleteCategory (req, res, next) {
  const session = await db.startSession()
  session.startTransaction()
  try {
    const templateQuery1 = await Template.deleteMany({ ancestorsIds: { $all: [req.params.id] } })
    const categoryQuery1 = await Category.deleteMany({ ancestorsIds: { $all: [req.params.id] } })
    const categoryQuery2 = await Category.deleteOne({ _id: req.params.id })
    const category = await Category.findById({ _id: req.params.id })
    const subCategory = await Category.find({ ancestorsIds: { $all: [req.params.id] } })
    const template = await Template.find({ ancestorsIds: { $all: [req.params.id] } })
    session.commitTransaction()
    return successResponse(res, {
      message: DELETE_CATEGORY_SUCCESS,
      data: {
        templateQuery1,
        categoryQuery1,
        categoryQuery2,
        category,
        subCategory,
        template
      }
    })
  } catch (e) {
    session.abortTransaction()
    const dbError = new DBError({
      status: DELETE_CATEGORY_ERROR,
      message: e.message
    })
    moduleErrLogMessager(dbError)
    next(new ApiError({ message: DELETE_CATEGORY_ERROR }))
  } finally {
    session.endSession()
  }
}

🚀 About Me

My name is Faithful Ojebiyi.

I am a framework-agnostic Backend Heavy Javascript developer;

• 🌱 I’m currently learning how to build D3Apps using blockchain
• 🖥 My current development stack is React, Vuejs, Nextjs, Nuxt, Nodejs, MongoDB, PostgreSQL, MySQL, Redis Expressjs, Python, Flask, Docker,
• 📫 How to reach me: faithfulojebiyi@gmail.com
• 😄 Pronouns: He/Him
• ⚡ Fun fact: I turn coffee to code and music keeps me going. I am a perfectionist
• 🏅 Github Profile Visits