salma-2 / ktorclient

KtorClient

• Why Ktor
• Add Dependencies and Permissions
• DTO
• API

Why Ktor on client-side?

Ktor is built on Kotlin multi-platform mobile (KMM). This means you can create both iOS and Android applications with Kotlin and share a huge part of Kotlin code for both platforms.

Add Dependencies and Permissions

add internet permission in AndroidManifest.xml. required to make HTTP requests to the API

<uses-permission android:name="android.permission.INTERNET"/>

in build.gradle(:app)

dependencies {
    ...
    def ktor_version = "1.6.3"
    // adds Ktor's core components to our project.
    implementation "io.ktor:ktor-client-core:$ktor_version"
    
    // HTTP engine: The HTTP client used to perform network requests, for iOS, we would use an iOS dependency.
    implementation "io.ktor:ktor-client-android:$ktor_version"
    
    // convert objects to and from JSON.
    implementation "io.ktor:ktor-client-serialization:$ktor_version"
    
    //Logging
    implementation "io.ktor:ktor-client-logging:$ktor_version"
    // allows us to see nicely formatted logs in a console.
    implementation "ch.qos.logback:logback-classic:1.2.3"

    // provides a convenient mechanism for converting Kotlin objects into a serialized form like JSON, and vice vers
    implementation "org.jetbrains.kotlinx:kotlinx-serialization-json:1.3.0"
}

apply plugin for kotlinx-serialization

plugins {
    ...
    id 'org.jetbrains.kotlin.plugin.serialization'
    ...
}

add classpath in build.gradle project file

dependencies {
        classpath "org.jetbrains.kotlin:kotlin-serialization:1.5.21"
}

Setup the data models

• A model is a data transfer object(dto). It has data classes that represent what we get from an API.
• inside remote.data.dto package create new data class called PostResponse, and create another one for requests.
• we'll get data from this API

Here's how the PostResponse will look like:

@Serializable
data class PostResponse(
    val body: String,
    val title: String,
    val id: Int,
    val userId: Int,
)

Setup the API

1. setup the api endpoint

• create a new Kotlin Object file named HttpRoutes

object HttpRoutes {
    private const val BASE_URL = "https://jsonplaceholder.typicode.com"
    const val POSTS = "$BASE_URL/posts"
}

2. define which functions we need to access the endpoints.

• create PostsService interface that will have mainly 2 functions (getPosts() and createPost(postRequest))
• create PostsServiceImpl to implement the actual network call using the Ktor client Impl

Reference