Kotlin Flows With Room Database

kotlin flows

In Kotlin we are using state flows to observe data when some change occurs. As state flows are powerful observers introduced by kotlin to use with kotlin coroutines to perform asynchronous operations. Moreover, a suspending function asynchronously returns a single value, but the critical question is how can we return multiple asynchronously computed values? In Kotlin coroutines, a flow is a type that can be able to emit multiple values sequentially like receiving live updates from a database, as opposed to suspend functions that return just only a single value. This article aims to discuss the main concepts, entities, and async possibilities in Kotlin flow.

I followed MVVM design pattern.

Room Entities:

Let's design the room entity first.

@Parcelize
@Entity(tableName = "books")
data class BooksResponse(
    @PrimaryKey
    @SerializedName("_id")
    var _id:String,
    @SerializedName("id")
    var id:String?=null,
    @SerializedName("title")
    var title:String?=null,
    @SerializedName("author")
    var author:String?=null,
    @SerializedName("about")
    var about:String?=null,
    @SerializedName("url")
    var url:String?=null,
): Parcelable

Table name is the optional parameter to give the name to a table.

Room Dao: