Mobile Kotlin network components

This is a Kotlin MultiPlatform library that provide network components for iOS & Android. Library is addition to ktor-client with gradle plugin to generate entities and api classes from OpenAPI (Swagger) specification file. Entities serialization done by kotlinx.serialization.

Table of Contents

• Features
• Requirements
• Installation
• Usage
• Samples
• Set Up Locally
• Contributing
• License

Features

• OpenAPI client code generation - just configure plugin then use generated entities and api classes;
• TokenFeature feature to ktor-client with auth token header support;
• ExceptionFeature feature to ktor-client that parse errors from server to domain exceptions.
• RefreshTokenFeature feature to ktor-client that handle Unauthorized response from server, try to update token and repeat failed request in case, when token update was successful;

Requirements

• Gradle version 6.8+
• Android API 16+
• iOS version 11.0+

Installation

root build.gradle

buildscript {
    repositories {
        gradlePluginPortal()
    }

    dependencies {
        classpath "dev.icerock.moko:network-generator:0.21.0"
    }
}


allprojects {
    repositories {
        mavenCentral()
    }
}

project build.gradle

apply plugin: "dev.icerock.mobile.multiplatform-network-generator"

dependencies {
    commonMainApi("dev.icerock.moko:network:0.21.0")
    commonMainApi("dev.icerock.moko:network-engine:0.21.0") // configured HttpClientEngine
    commonMainApi("dev.icerock.moko:network-bignum:0.21.0") // kbignum serializer
    commonMainApi("dev.icerock.moko:network-errors:0.21.0") // moko-errors integration
}

Usage

1. E.g. put an OpenAPI Specification file to src/swagger.json path of the project Gradle module.

2. Setup the project build.gradle:

mokoNetwork {
    spec("pets") {
        inputSpec = file("src/swagger.json")
    }
    spec("news") {
        inputSpec = file("src/newsApi.yaml")
        packageName = "news"
        isInternal = false
        isOpen = true
        configureTask {
            // here can be configuration of https://github.com/OpenAPITools/openapi-generator GenerateTask
        }
        enumFallbackNull = false
    }
}

3. Then run openApiGenerate Gradle task and after completion you will get all generated classes in build/generated/moko-network directory.

4. To import all generated classes of model put:

import dev.icerock.moko.network.generated.models.*

import dev.icerock.moko.network.generated.apis.*

5. Then you can use generated API's in your application in the common sourceset:

import dev.icerock.moko.network.generated.apis.*

class TestViewModel : ViewModel() {
    // ..
    
    private val petApi = PetApi(
        basePath = "https://petstore.swagger.io/v2/", // Base API URL
        httpClient = ktorHttpClient, // Reference to Ktor HTTP client object
        json = kotlinxJsonParser // Reference to kotlinx.serialization.json parser object
    )

    fun apiRequest() {
        viewModelScope.launch {
            try {
                val pet = petApi.findPetsByStatus(listOf("available"))

                // ...
            } catch (error: Exception) {
                // ...
            }
        }
    }
}

For the moko-network specification generator, you can enable safe enum properties generation mode. To turn on the mode in build.gradle to a spec block add flag:

enumFallbackNull = true

The enabled mode will generate special wrapper Safeable for all properties with the enum type, that which in a situation for an unexpected enum value will return null.

Deprecated usage

Old way with OpenApi Generator Plugin available by:

apply plugin: "dev.icerock.mobile.multiplatform-network-generator-deprecated"

openApiGenerate {
    inputSpec.set(file("src/swagger.json").path)
    generatorName.set("kotlin-ktor-client")
}

but this way limited to one spec in one time.

moko-network-errors

There is module moko-network-errors for moko-errors library that contains built-in mappers for mapping moko-network exception classes into StringDesc objects (there are built-in resources for text in English and Russian).

To use the moko-network-errors module just call the registerAllNetworkMappers extension of ExceptionMappersStorage object:

fun initExceptionMappersStorage() {
    ExceptionMappersStorage.registerAllNetworkMappers()
}

And then you can use ExceptionHandler to automatically handle exceptions for network requests:

viewModelScope.launch {
    exceptionHandler.handle {
        val pet = petApi.findPetsByStatus(listOf("available"))

        // ...
    }.execute()
}

For more information about exception handling see moko-errors.

Samples

More examples can be found in the sample directory.

Set Up Locally

• In network directory contains network library;
• In network-errors directory contains network-errors module;
• In plugins directory contains gradle plugin with OpenAPI implementation generator;
• In sample directory contains samples on android, ios & mpp-library connected to apps.

Contributing

All development (both new features and bug fixes) is performed in develop branch. This way master sources always contain sources of the most recently released version. Please send PRs with bug fixes to develop branch. Fixes to documentation in markdown files are an exception to this rule. They are updated directly in master.

The develop branch is pushed to master during release.

More detailed guide for contributers see in contributing guide.

License

Copyright 2019 IceRock MAG Inc

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.