Add ECP support to Android Checkout Kit

Author: tiagocandido

android/README.md

@@ -55,7 +55,7 @@ your project:
 ### Gradle
 
 ```groovy
-implementation "com.shopify:checkout-kit:3.6.0"
+implementation "com.shopify:checkout-kit:1.0.0"
 ```
 
 ### Maven
@@ -65,7 +65,7 @@ implementation "com.shopify:checkout-kit:3.6.0"
 <dependency>
    <groupId>com.shopify</groupId>
    <artifactId>checkout-kit</artifactId>
-   <version>3.6.0</version>
+   <version>1.0.0</version>
 </dependency>
 ```
 

android/lib/api/lib.api

@@ -16,7 +16,7 @@ def resolveEnvVarValue(name, defaultValue) {
     return rawValue ? rawValue : defaultValue
 }
 
-def versionName = resolveEnvVarValue("CHECKOUT_KIT_VERSION", "3.6.0")
+def versionName = resolveEnvVarValue("CHECKOUT_KIT_VERSION", "1.0.0")
 
 ext {
     app_compat_version = '1.7.1'
@@ -141,6 +141,11 @@ detekt {
     autoCorrect = true
 }
 
+// Models.kt is generated from UCP JSON Schemas — exclude it from static analysis.
+tasks.withType(io.gitlab.arturbosch.detekt.Detekt).configureEach {
+    exclude('**/Models.kt')
+}
+
 
 project.afterEvaluate {
     publishing {

android/lib/build.gradle

@@ -57,8 +57,6 @@ internal abstract class BaseWebView(context: Context, attributeSet: AttributeSet
 
     abstract fun getEventProcessor(): CheckoutWebViewEventProcessor
     abstract val recoverErrors: Boolean
-    abstract val variant: String
-    abstract val cspSchema: String
 
     private fun configureWebView() {
         visibility = VISIBLE
@@ -125,11 +123,11 @@ internal abstract class BaseWebView(context: Context, attributeSet: AttributeSet
     private fun isOnConfirmationPage(): Boolean = url?.let(Uri::parse).isConfirmationPage()
 
     internal fun userAgentSuffix(): String {
-        val theme = ShopifyCheckoutKit.configuration.colorScheme.id
-        val version = ShopifyCheckoutKit.version.split("-").first()
         val platform = ShopifyCheckoutKit.configuration.platform
-        val platformSuffix = if (platform != null) " ${platform.displayName}" else ""
-        val suffix = "ShopifyCheckoutSDK/$version ($cspSchema;$theme;$variant)$platformSuffix"
+        val suffix = buildString {
+            append("ShopifyCheckoutKit/${BuildConfig.SDK_VERSION} android")
+            if (platform != null) append(" ${platform.displayName}")
+        }
         log.d(LOG_TAG, "Setting User-Agent suffix $suffix")
         return suffix
     }

android/lib/src/main/java/com/shopify/checkoutkit/BaseWebView.kt

@@ -23,7 +23,6 @@
 package com.shopify.checkoutkit
 
 import android.webkit.JavascriptInterface
-import android.webkit.WebView
 import com.shopify.checkoutkit.CheckoutBridge.CheckoutWebOperation.COMPLETED
 import com.shopify.checkoutkit.CheckoutBridge.CheckoutWebOperation.ERROR
 import com.shopify.checkoutkit.CheckoutBridge.CheckoutWebOperation.MODAL
@@ -33,7 +32,6 @@ import com.shopify.checkoutkit.errorevents.CheckoutErrorDecoder
 import com.shopify.checkoutkit.lifecycleevents.CheckoutCompletedEventDecoder
 import com.shopify.checkoutkit.pixelevents.PixelEventDecoder
 import kotlinx.serialization.Serializable
-import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
 
 internal class CheckoutBridge(
@@ -66,11 +64,6 @@ internal class CheckoutBridge(
         }
     }
 
-    sealed class SDKOperation(val key: String) {
-        data object Presented : SDKOperation("presented")
-        class Instrumentation(val payload: InstrumentationPayload) : SDKOperation("instrumentation")
-    }
-
     // Allows Web to postMessages back to the SDK
     @Suppress("SwallowedException")
     @JavascriptInterface
@@ -137,73 +130,11 @@ internal class CheckoutBridge(
         }
     }
 
-    // Send messages from SDK to Web
-    @Suppress("SwallowedException")
-    fun sendMessage(view: WebView, operation: SDKOperation) {
-        val script = when (operation) {
-            is SDKOperation.Presented -> {
-                log.d(LOG_TAG, "Sending presented message to checkout, informing it that the sheet is now visible.")
-                dispatchMessageTemplate("'${operation.key}'")
-            }
-
-            is SDKOperation.Instrumentation -> {
-                log.d(LOG_TAG, "Sending instrumentation message to checkout.")
-                val body = Json.encodeToString(SdkToWebEvent(operation.payload))
-                dispatchMessageTemplate("'${operation.key}', $body")
-            }
-        }
-        try {
-            view.evaluateJavascript(script, null)
-        } catch (e: Exception) {
-            log.d(LOG_TAG, "Failed to send message to checkout, invoking onCheckoutViewFailedWithError")
-            onMainThread {
-                eventProcessor.onCheckoutViewFailedWithError(
-                    CheckoutKitException(
-                        errorDescription = "Failed to send '${operation.key}' message to checkout, some features may not work.",
-                        errorCode = CheckoutKitException.ERROR_SENDING_MESSAGE_TO_CHECKOUT,
-                        isRecoverable = true,
-                    )
-                )
-            }
-        }
-    }
-
     companion object {
         private const val LOG_TAG = "CheckoutBridge"
-        const val SCHEMA_VERSION_NUMBER: String = "8.1"
-
-        private fun dispatchMessageTemplate(body: String) = """|
-        |if (window.MobileCheckoutSdk && window.MobileCheckoutSdk.dispatchMessage) {
-        |    window.MobileCheckoutSdk.dispatchMessage($body);
-        |} else {
-        |    window.addEventListener('mobileCheckoutBridgeReady', function () {
-        |        window.MobileCheckoutSdk.dispatchMessage($body);
-        |    }, {passive: true, once: true});
-        |}
-        |
-        """.trimMargin()
     }
 }
 
-@Serializable
-internal data class SdkToWebEvent<T>(
-    val detail: T
-)
-
-@Serializable
-internal data class InstrumentationPayload(
-    val name: String,
-    val value: Long,
-    val type: InstrumentationType,
-    val tags: Map<String, String>
-)
-
-@Suppress("EnumNaming", "EnumEntryNameCase")
-@Serializable
-internal enum class InstrumentationType {
-    histogram
-}
-
 @Serializable
 internal data class WebToSdkEvent(
     val name: String,

android/lib/src/main/java/com/shopify/checkoutkit/CheckoutBridge.kt

@@ -0,0 +1,53 @@
+/*
+ * MIT License
+ *
+ * Copyright 2023-present, Shopify Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.shopify.checkoutkit
+
+import android.net.Uri
+
+/**
+ * Implement this interface to handle Embedded Checkout Protocol (ECP) messages beyond
+ * the built-in methods handled natively by the SDK.
+ *
+ * Register an implementation via [ShopifyCheckoutKit.present].
+ */
+public interface CheckoutCommunicationClient {
+    /**
+     * Process a JSON-RPC 2.0 ECP message from the checkout web page.
+     *
+     * Called for all EC notifications (ec.start, ec.error, ec.complete, ec.*.change)
+     * and any unknown methods. For requests, return a JSON-RPC 2.0 response string;
+     * for notifications, return null (no response is sent).
+     *
+     * @param message JSON-RPC 2.0 encoded message string
+     * @return JSON-RPC 2.0 encoded response string, or null to send no response
+     */
+    public fun process(message: String): String?
+
+    /**
+     * Called when checkout requests that a URL be opened externally (ec.window.open_request).
+     *
+     * @param url the URL checkout wants opened in an external browser or app
+     * @return true if the URL was handled and displayed externally, false otherwise
+     */
+    public fun openExternalUrl(url: Uri): Boolean
+}

android/lib/src/main/java/com/shopify/checkoutkit/CheckoutCommunicationClient.kt

@@ -55,6 +55,7 @@ internal class CheckoutDialog(
     private val checkoutUrl: String,
     private val checkoutEventProcessor: CheckoutEventProcessor,
     context: Context,
+    private val communicationClient: CheckoutCommunicationClient? = null,
 ) : ComponentDialog(context) {
 
     internal var recoveryAttemptCount = 0
@@ -91,6 +92,8 @@ internal class CheckoutDialog(
         checkoutWebView.onResume()
         log.d(LOG_TAG, "Setting event processor on WebView.")
         checkoutWebView.setEventProcessor(eventProcessor())
+        log.d(LOG_TAG, "Setting communication client on WebView.")
+        checkoutWebView.setClient(communicationClient)
 
         val colorScheme = ShopifyCheckoutKit.configuration.colorScheme
         log.d(LOG_TAG, "Configured colorScheme $colorScheme")
@@ -124,11 +127,6 @@ internal class CheckoutDialog(
             removeWebViewFromContainer()
         }
 
-        setOnShowListener {
-            log.d(LOG_TAG, "On show listener invoked, calling WebView notifyPresented.")
-            checkoutWebView.notifyPresented()
-        }
-
         log.d(LOG_TAG, "Showing dialog.")
         show()
     }