What is dojo/store?

In web development, dojo/store refers to a module provided by the Dojo Toolkit, an open-source JavaScript toolkit. The dojo/store module is designed to provide a unified interface for accessing and manipulating data from various data sources, such as in-memory arrays, RESTful web services, or local storage.

The dojo/store module follows the store pattern, which abstracts the underlying data source and provides a consistent API for performing everyday data operations like querying, adding, updating, and deleting data. It promotes the separation of concerns by decoupling the data access logic from the user interface or application logic.

The dojo/store module allows developers to write data-driven applications more quickly and efficiently. They can interact with different data sources using a uniform API, simplifying the code and reducing the complexity of handling various data retrieval and manipulation tasks.

Features

The dojo/store module provides a set of features and functionalities for managing and interacting with data in web applications. Here are its few key features:

• Abstraction of data storage: The dojo/store module abstracts the details of data storage, providing a consistent interface for working with various types of data stores.

• Memory store: The Memory store is a simple in-memory data store that allows us to store and manipulate data on the client side.

• Querying data: The dojo/store module provides a querying mechanism that allows us to filter and retrieve specific data from the store based on certain conditions.

Applications

One of the real-world applications of the dojo/store module is the Dojo Toolkit website. The official website of the Dojo Toolkit itself is built using Dojo. This serves as a demonstration of the framework’s capabilities and its use in creating modern, feature-rich web applications.

Advantages

Here are a few advantages of the dojo/store module:

• Its modular architecture allows for the creation of reusable components, promoting a modular and maintainable codebase.

• It provides a comprehensive set of UI widgets, making it easier to create feature-rich and interactive user interfaces without building everything from scratch.

• It is designed to provide cross-browser compatibility, helping developers create consistent experiences across different web browsers.

Limitations

Here are a few limitations of the dojo/store module:

• Some developers find that there is a learning curve associated with Dojo, especially when compared to more lightweight libraries. The modular structure and extensive feature set can be overwhelming for beginners.

• Including the entire Dojo toolkit in a project can result in a larger file size. This may impact page load times, especially if not all features are utilized.

• While Dojo provides many features, some developers may find that not all features are needed for their projects, leading to a perception of unnecessary complexity.

Syntax of the dojo/store module

The syntax for the dojo/store module involves creating a data store instance and performing various operations on it, such as querying, adding, updating, and deleting data.

Here’s an overview of the syntax for using the dojo/store module:

• We import the requirements, as shown below:

• We create an instance for the data store, as follows:

• We perform the following functions:
  • Fetch data using the query method:

store.query({ /* Our query object goes here */ }).forEach(function (item) {
    // Do something with the fetched item
});

• Add new items using the add method:

const newItem = { /* New item data goes here */ };
store.add(newItem);
});

• Update existing items using the put method:

const updatedItem = { /* Updated item data goes here (including the id property) */ };
store.put(updatedItem);
});

• Delete items using the remove method:

const itemId = 123; // The id of the item we want to delete
store.remove(itemId);
});

Example

Here’s a simple example of how the dojo/store module is used to retrieve data from an in-memory array:

• Line 6: We load Dojo using this CDN link.

• Line 8: We import the “dojo/store/Memory” module using the require function. This module provides an in-memory data store implementation.

• Lines 9–21: Inside the require callback, we define an array called data. It contains three objects representing user data, each with properties such as id, name, and age. This array represents the initial data for the data store.

• Lines 22–24: We create a new instance of the Memory store using the new Memory({ data: data }) syntax. We pass the Memory constructor as an object with a data property set to the data array. This initializes the data store with the provided data.

• Lines 26–30: We call the store.query() method to perform a query on the data store. The query object is { age: { ＄gt: 30 } }, which specifies that we want to find items where the age property is greater than 30. In this case, it will match the third user object in the data array. We call the forEach method on the query result to iterate over the matched items. In each iteration, the item parameter represents an individual item that matches the query. Inside the forEach callback, we call the console.log(item.name) to output each matched item’s name property to the console.

We can check the Dojo Toolkit documentation or resources specific to the working version for more detailed information.