jan/docs/docs/reference/data_plugin.md

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1	data plugin

Data Plugin

This module provides functions for interacting with data storage using (PouchDB) as the underlying database.

Usage

Create a collection

In this example, we will create a collection named my-collection without schema. The database will be located as at: AppData + /dabatases/my-collection. AppData will depends on your OS where you install Jan app: AppData Per-user application data directory, which by default points to:

• %APPDATA% on Windows
• $XDG_CONFIG_HOME or ~/.config on Linux
• ~/Library/Application Support on macOS

For example, the database location in macOS would be /Users/$(whoami)/Library/Application\ Support/jan/databases/my-collection

const store = require("@janhq/core");
store.createCollection({ name: "my-collection", schema: {} });

Delete a collection

Delete my-collection database.

const store = require("@janhq/core");
store.deleteCollection({"my-collection"});

Create a document

In this example, we'll create a document in my-collection database. The document comprises 3 field : _id: string , name: string, age: number. The insertOne function will return inserted id.

const store = require("@janhq/core");
const id = await store.insertOne("my-collection", {_id: "1", name: "Jan", age: 1});
// id = 1

Find one document

In the previous step, we just created a document with _id:"1". Let's try how to find it.

const store = require("@janhq/core");
const doc = await store.findOne("my-collection","1");
// {name: 'Jan', age: 1, _id: '1'}

Find many documents and sort the result

In this example, we will find all the documents that have age >= 1 with $gte operator and sort the result by name in descending order.

const store = require("@janhq/core");
const id1 = await store.insertOne("my-collection", {_id: "1", name: "Jan", age: 1});
const id2 = await store.insertOne("my-collection", {_id: "2", name: "James", age: 1});
const id3 = await store.insertOne("my-collection", {_id: "3", name: "Jack", age: 2});
const docs = await store.findMany("my-collection", {age: { $gte: 1 }}, [{ name : "desc"}]);
// [{"name":"Jan","age":1,"_id":"1",},
// {"name":"James","age":1,"_id":"2"},
// {"name":"Jack","age":2,"_id":"3"}]

For more operators, please follow:

• $lt Match fields “less than” this one.
• $gt Match fields “greater than” this one.
• $lte Match fields “less than or equal to” this one.
• $gte Match fields “greater than or equal to” this one.
• $eq Match fields equal to this one.
• $ne Match fields not equal to this one.
• $exists True if the field should exist, false otherwise.
• $type One of: “null”, “boolean”, “number”, “string”, “array”, or “object”.
• $in The document field must exist in the list provided.
• $and Matches if all the selectors in the array match.
• $nin The document field must not exist in the list provided.
• $all Matches an array value if it contains all the elements of the argument array.
• $size Special condition to match the length of an array field in a document.
• $or Matches if any of the selectors in the array match. All selectors must use the same index.
• $nor Matches if none of the selectors in the array match.
• $not Matches if the given selector does not match.
• $mod Matches documents where (field % Divisor == Remainder) is true, and only when the document field is an integer.
• $regex A regular expression pattern to match against the document field.
• $elemMatch Matches all documents that contain an array field with at least one element that matches all the specified query criteria.

Update a document

In this example, we will change the age from 1 to 5 in the document that has the id of "1"

const store = require("@janhq/core");
const id = await store.insertOne("my-collection", {_id: "1", name: "Jan", age: 1});
await store.updateOne("my-collection", "1", {name: "Jan", age: 5});

Update many documents

In this example, we will update the age to 10 in the documents that have age >= 1

const store = require("@janhq/core");
const id1 = await store.insertOne("my-collection", {_id: "1", name: "Jan", age: 1});
const id2 = await store.insertOne("my-collection", {_id: "2", name: "James", age: 1});
const id3 = await store.insertOne("my-collection", {_id: "3", name: "Jack", age: 2});
const docs = await store.updateMany("my-collection", {age:10}, {age: { $gte : 1 }});
// [{"name":"Jan","age":10,"_id":"1",},
// {"name":"James","age":10,"_id":"2"},
// {"name":"Jack","age":10,"_id":"3"}]

For more operators, please follow:

• $lt Match fields “less than” this one.
• $gt Match fields “greater than” this one.
• $lte Match fields “less than or equal to” this one.
• $gte Match fields “greater than or equal to” this one.
• $eq Match fields equal to this one.
• $ne Match fields not equal to this one.
• $exists True if the field should exist, false otherwise.
• $type One of: “null”, “boolean”, “number”, “string”, “array”, or “object”.
• $in The document field must exist in the list provided.
• $and Matches if all the selectors in the array match.
• $nin The document field must not exist in the list provided.
• $all Matches an array value if it contains all the elements of the argument array.
• $size Special condition to match the length of an array field in a document.
• $or Matches if any of the selectors in the array match. All selectors must use the same index.
• $nor Matches if none of the selectors in the array match.
• $not Matches if the given selector does not match.
• $mod Matches documents where (field % Divisor == Remainder) is true, and only when the document field is an integer.
• $regex A regular expression pattern to match against the document field.
• $elemMatch Matches all documents that contain an array field with at least one element that matches all the specified query criteria.

Delete a document

Delete the document which has id of "1"

const store = require("@janhq/core");
const id1 = await store.insertOne("my-collection", {_id: "1", name: "Jan", age: 1});
const doc = await store.deleteOne("my-collection","1");

Delete many documents

In this exmaple, we will delete documents that have age < 2

const store = require("@janhq/core");
const id1 = await store.insertOne("my-collection", {_id: "1", name: "Jan", age: 1});
const id2 = await store.insertOne("my-collection", {_id: "2", name: "James", age: 1});
const id3 = await store.insertOne("my-collection", {_id: "3", name: "Jack", age: 2});
const docs = await store.deleteMany("my-collection", {age: {$lt : 2}});

For more operators, please follow:

• $lt Match fields “less than” this one.
• $gt Match fields “greater than” this one.
• $lte Match fields “less than or equal to” this one.
• $gte Match fields “greater than or equal to” this one.
• $eq Match fields equal to this one.
• $ne Match fields not equal to this one.
• $exists True if the field should exist, false otherwise.
• $type One of: “null”, “boolean”, “number”, “string”, “array”, or “object”.
• $in The document field must exist in the list provided.
• $and Matches if all the selectors in the array match.
• $nin The document field must not exist in the list provided.
• $all Matches an array value if it contains all the elements of the argument array.
• $size Special condition to match the length of an array field in a document.
• $or Matches if any of the selectors in the array match. All selectors must use the same index.
• $nor Matches if none of the selectors in the array match.
• $not Matches if the given selector does not match.
• $mod Matches documents where (field % Divisor == Remainder) is true, and only when the document field is an integer.
• $regex A regular expression pattern to match against the document field.
• $elemMatch Matches all documents that contain an array field with at least one element that matches all the specified query criteria.

How to contribute

1. Go to Jan
2. Create an Issue for plugins
3. Create a PR to main branch
4. Once it's merged, the new model will be on Jan plugin to use.