Update README.md to use new plugins DSL

README.md

@@ -22,19 +22,29 @@ class and in the Android manifest file.
 
 Groovy:
 ```groovy
-buildscript {
-    dependencies {
-        classpath "com.google.android.libraries.mapsplatform.secrets-gradle-plugin:secrets-gradle-plugin:2.0.1"
-    }
+plugins {
+    id "com.google.android.libraries.mapsplatform.secrets-gradle-plugin" version "2.0.1" apply false
 }
 ```
 
 Kotlin:
 ```kotlin
-buildscript {
-    dependencies {
-        classpath("com.google.android.libraries.mapsplatform.secrets-gradle-plugin:secrets-gradle-plugin:2.0.1")
-    }
+plugins {
+    id("com.google.android.libraries.mapsplatform.secrets-gradle-plugin") version "2.0.1" apply false
+}
+```
+
+With a TOML version catalog:
+```toml
+[versions]
+secrets = "2.0.1"
+
+[plugins]
+secrets = { id = "com.google.android.libraries.mapsplatform.secrets-gradle-plugin", version.ref = "secrets" }
+```
+```kotlin
+plugins {
+    alias(libs.plugins.secrets) apply false
 }
 ```
 
@@ -54,6 +64,13 @@ plugins {
 }
 ```
 
+With a TOML version catalog:
+```kotlin
+plugins {
+    alias(libs.plugins.secrets)
+}
+```
+
 This plugin also supports library module type (`com.android.library`). Just install the plugin in your library-level `build.gradle` file and keys will be visible inside that module as well.
 
 ### Snapshot Releases

secrets-gradle-plugin/bin/main/com/google/android/libraries/mapsplatform/secrets_gradle_plugin/Extensions.kt

@@ -0,0 +1,99 @@
+// Copyright 2021 Google LLC
+//
+// 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.
+
+@file:Suppress("UnstableApiUsage")
+
+package com.google.android.libraries.mapsplatform.secrets_gradle_plugin
+
+import com.android.build.api.variant.ApplicationAndroidComponentsExtension
+import com.android.build.api.variant.BuildConfigField
+import com.android.build.api.variant.LibraryAndroidComponentsExtension
+import com.android.build.api.variant.Variant
+import com.android.build.gradle.AppExtension
+import com.android.build.gradle.LibraryExtension
+import com.android.build.gradle.internal.core.InternalBaseVariant
+import org.gradle.api.Project
+import java.io.FileNotFoundException
+import java.util.Properties
+
+fun Project.androidAppComponent(): ApplicationAndroidComponentsExtension? =
+    extensions.findByType(ApplicationAndroidComponentsExtension::class.java)
+
+fun Project.androidLibraryComponent(): LibraryAndroidComponentsExtension? =
+    extensions.findByType(LibraryAndroidComponentsExtension::class.java)
+
+fun Project.androidProject(): AppExtension? =
+    extensions.findByType(AppExtension::class.java)
+
+fun Project.libraryProject(): LibraryExtension? =
+    extensions.findByType(LibraryExtension::class.java)
+
+fun Project.loadPropertiesFile(fileName: String): Properties {
+    // Load file
+    val propertiesFile = file(fileName)
+    if (!propertiesFile.exists()) {
+        throw FileNotFoundException(
+            "The file '${propertiesFile.absolutePath}' could not be found"
+        )
+    }
+
+    // Load contents into properties object
+    val properties = Properties()
+    properties.load(propertiesFile.inputStream())
+    return properties
+}
+
+private val javaVarRegexp = Regex(pattern = "((?![a-zA-Z_\$0-9]).)")
+
+fun Variant.inject(properties: Properties, ignore: List<String>) {
+    val ignoreRegexs = ignore.map { Regex(pattern = it) }
+    properties.keys.map { key ->
+        key as String
+    }.filter { key ->
+        key.isNotEmpty() && !ignoreRegexs.any { it.containsMatchIn(key) }
+    }.forEach { key ->
+        val value = properties.getProperty(key).removeSurrounding("\"")
+        val translatedKey = key.replace(javaVarRegexp, "")
+        buildConfigFields.put(
+            translatedKey,
+            BuildConfigField("String", value.addParenthesisIfNeeded(), null)
+        )
+        manifestPlaceholders.put(translatedKey, value)
+    }
+}
+
+fun InternalBaseVariant.inject(properties: Properties, ignore: List<String>) {
+    val ignoreRegexs = ignore.map { Regex(pattern = it) }
+    properties.keys.map { key ->
+        key as String
+    }.filter { key ->
+        key.isNotEmpty() && !ignoreRegexs.any { it.containsMatchIn(key) }
+    }.forEach { key ->
+        val value = properties.getProperty(key).removeSurrounding("\"")
+        val translatedKey = key.replace(javaVarRegexp, "")
+        buildConfigField("String", translatedKey, value.addParenthesisIfNeeded())
+        mergedFlavor.manifestPlaceholders[translatedKey] = value
+    }
+}
+
+fun String.addParenthesisIfNeeded(): String {
+    if (isEmpty()) {
+        return this
+    }
+    val charArray = this.toCharArray()
+    if (length > 1 && charArray[0] == '"' && charArray[charArray.size - 1] == '"') {
+        return this
+    }
+    return "\"$this\""
+}

secrets-gradle-plugin/bin/main/com/google/android/libraries/mapsplatform/secrets_gradle_plugin/SecretsPlugin.kt

@@ -0,0 +1,100 @@
+// Copyright 2021 Google LLC
+//
+// 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.
+@file:Suppress("UnstableApiUsage")
+
+package com.google.android.libraries.mapsplatform.secrets_gradle_plugin
+
+import com.android.build.api.variant.Variant
+import com.android.build.gradle.internal.core.InternalBaseVariant
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import java.io.FileNotFoundException
+import java.util.Properties
+
+/**
+ * Plugin that reads secrets from a properties file and injects manifest build and BuildConfig
+ * variables into an Android project. Since property keys are turned into Java variables,
+ * invalid variable characters from the property key are removed.
+ *
+ * e.g.
+ * A key defined as "sdk.dir" in the properties file will be converted to "sdkdir".
+ */
+class SecretsPlugin : Plugin<Project> {
+
+    private val extensionName = "secrets"
+
+    override fun apply(project: Project) {
+        val extension = project.extensions.create(
+            extensionName,
+            SecretsPluginExtension::class.java
+        )
+        val supportedComponents =
+            listOf(project.androidAppComponent(), project.androidLibraryComponent())
+        supportedComponents.forEach { component ->
+            component?.onVariants { variant ->
+                val defaultProperties = extension.defaultPropertiesFileName?.let {
+                    project.rootProject.loadPropertiesFile(it)
+                }
+
+                val properties: Properties? = try {
+                    project.rootProject.loadPropertiesFile(
+                        extension.propertiesFileName
+                    )
+                } catch (e: FileNotFoundException) {
+                    defaultProperties ?: throw e
+                }
+                generateConfigKey(project, extension, defaultProperties, properties, variant)
+            }
+        }
+    }
+
+    private fun generateConfigKey(
+        project: Project,
+        extension: SecretsPluginExtension,
+        defaultProperties: Properties?,
+        properties: Properties?,
+        variant: Variant
+    ) {
+        // Inject defaults first
+        defaultProperties?.let {
+            variant.inject(it, extension.ignoreList)
+        }
+
+        properties?.let {
+            variant.inject(properties, extension.ignoreList)
+        }
+
+        // Inject build-type specific properties
+        val buildTypeFileName = "${variant.buildType}.properties"
+        val buildTypeProperties = try {
+            project.rootProject.loadPropertiesFile(buildTypeFileName)
+        } catch (e: FileNotFoundException) {
+            null
+        }
+        buildTypeProperties?.let {
+            variant.inject(it, extension.ignoreList)
+        }
+
+        // Inject flavor-specific properties
+        val flavorFileName = "${variant.flavorName}.properties"
+        val flavorProperties = try {
+            project.rootProject.loadPropertiesFile(flavorFileName)
+        } catch (e: FileNotFoundException) {
+            null
+        }
+        flavorProperties?.let {
+            variant.inject(it, extension.ignoreList)
+        }
+    }
+}

secrets-gradle-plugin/bin/main/com/google/android/libraries/mapsplatform/secrets_gradle_plugin/SecretsPluginExtension.kt

@@ -0,0 +1,40 @@
+// Copyright 2021 Google LLC
+//
+// 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.
+
+package com.google.android.libraries.mapsplatform.secrets_gradle_plugin
+
+/**
+ * Configuration object for [SecretsPlugin].
+ */
+open class SecretsPluginExtension {
+    /**
+     * The name of the properties file containing secrets. Defaults to "$defaultPropertiesFile"
+     */
+    var propertiesFileName: String = defaultPropertiesFile
+
+    /**
+     * A list of keys this plugin should ignore and not inject. Defaults to $defaultIgnoreList
+     */
+    var ignoreList: MutableList<String> = defaultIgnoreList
+
+    /**
+     * The name of the properties file containing secrets' default values.
+     */
+    var defaultPropertiesFileName: String? = null
+
+    companion object {
+        const val defaultPropertiesFile = "local.properties"
+        val defaultIgnoreList = mutableListOf("sdk.dir")
+    }
+}