Spliting site and the snark project complete

build.gradle.kts

@@ -9,10 +9,10 @@ allprojects {
     if(name!="snark-gradle-plugin") {
         tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
             kotlinOptions {
-                freeCompilerArgs = freeCompilerArgs + "-Xcontext-receivers"
+                freeCompilerArgs = freeCompilerArgs  + "-Xcontext-receivers"
             }
         }
     }
 }
 
-val dataforgeVersion by extra("0.6.0-dev-9")
+val dataforgeVersion by extra("0.6.0-dev-10")

snark-core/src/commonMain/kotlin/space/kscience/snark/SnarkEnvironment.kt

@@ -0,0 +1,40 @@
+package space.kscience.snark
+
+import space.kscience.dataforge.context.Context
+import space.kscience.dataforge.context.Global
+import space.kscience.dataforge.context.Plugin
+import space.kscience.dataforge.data.DataSourceBuilder
+import space.kscience.dataforge.data.DataTree
+import space.kscience.dataforge.data.DataTreeBuilder
+import space.kscience.dataforge.meta.MutableMeta
+import kotlin.reflect.typeOf
+
+public class SnarkEnvironment(public val parentContext: Context) {
+    private var _data: DataTree<*>? = null
+    public val data: DataTree<Any> get() = _data ?: DataTree.empty()
+
+    public fun data(builder: DataSourceBuilder<Any>.() -> Unit) {
+        _data = DataTreeBuilder<Any>(typeOf<Any>(), parentContext.coroutineContext).apply(builder)
+        //TODO use node meta
+    }
+
+    public val meta: MutableMeta = MutableMeta()
+
+    public fun meta(block: MutableMeta.() -> Unit) {
+        meta.apply(block)
+    }
+
+    private val _plugins = HashSet<Plugin>()
+    public val plugins: Set<Plugin> get() = _plugins
+
+    public fun registerPlugin(plugin: Plugin) {
+        _plugins.add(plugin)
+    }
+
+    public companion object{
+        public val default: SnarkEnvironment = SnarkEnvironment(Global)
+    }
+}
+
+public fun SnarkEnvironment(parentContext: Context = Global, block: SnarkEnvironment.() -> Unit): SnarkEnvironment =
+    SnarkEnvironment(parentContext).apply(block)

snark-core/src/commonMain/kotlin/space/kscience/snark/SnarkParser.kt

@@ -4,9 +4,12 @@ import io.ktor.utils.io.core.Input
 import io.ktor.utils.io.core.readBytes
 import space.kscience.dataforge.context.Context
 import space.kscience.dataforge.io.IOReader
+import space.kscience.dataforge.io.asBinary
+import space.kscience.dataforge.io.readWith
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.misc.Type
 import kotlin.reflect.KType
+import kotlin.reflect.typeOf
 
 /**
  * A parser of binary content including priority flag and file extensions
@@ -31,4 +34,22 @@ public interface SnarkParser<out R> {
         public const val TYPE: String = "snark.parser"
         public const val DEFAULT_PRIORITY: Int = 10
     }
-}
+}
+
+@PublishedApi
+internal class SnarkParserWrapper<R : Any>(
+    val reader: IOReader<R>,
+    override val type: KType,
+    override val fileExtensions: Set<String>,
+) : SnarkParser<R> {
+    override fun parse(context: Context, meta: Meta, bytes: ByteArray): R = bytes.asBinary().readWith(reader)
+}
+
+/**
+ * Create a generic parser from reader
+ */
+@Suppress("FunctionName")
+public inline fun <reified R : Any> SnarkParser(
+    reader: IOReader<R>,
+    vararg fileExtensions: String,
+): SnarkParser<R> = SnarkParserWrapper(reader, typeOf<R>(), fileExtensions.toSet())

snark-html/src/main/kotlin/space/kscience/snark/html/HtmlData.kt

@@ -16,7 +16,7 @@ import space.kscience.snark.SnarkContext
 //typealias HtmlFragment = context(PageBuilder, TagConsumer<*>) () -> Unit
 
 public fun interface HtmlFragment {
-    public fun TagConsumer<*>.renderFragment(page: Page)
+    public fun TagConsumer<*>.renderFragment(page: WebPage)
     //TODO move pageBuilder to a context receiver after KT-52967 is fixed
 }
 
@@ -26,7 +26,7 @@ public typealias HtmlData = Data<HtmlFragment>
 //    Data(HtmlFragment(content), meta)
 
 
-context(Page) public fun FlowContent.htmlData(data: HtmlData): Unit = runBlocking(Dispatchers.IO) {
+context(WebPage) public fun FlowContent.htmlData(data: HtmlData): Unit = runBlocking(Dispatchers.IO) {
     with(data.await()) { consumer.renderFragment(page) }
 }
 

snark-html/src/main/kotlin/space/kscience/snark/html/SiteBuilder.kt

@@ -4,15 +4,12 @@ import kotlinx.html.HTML
 import space.kscience.dataforge.context.Context
 import space.kscience.dataforge.context.ContextAware
 import space.kscience.dataforge.data.DataTree
-import space.kscience.dataforge.data.DataTreeItem
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.NameToken
 import space.kscience.dataforge.names.parseAsName
 import space.kscience.snark.SnarkContext
 import java.nio.file.Path
-import kotlin.reflect.KType
-import kotlin.reflect.typeOf
 
 
 /**
@@ -20,27 +17,46 @@ import kotlin.reflect.typeOf
  */
 public interface SiteBuilder : ContextAware, SnarkContext {
 
+    /**
+     * Data used for site construction. The type of the data is not limited
+     */
     public val data: DataTree<*>
 
-    public val snark: SnarkPlugin
+    /**
+     * Snark plugin and context used for layout resolution, preprocessors, etc
+     */
+    public val snark: SnarkHtmlPlugin
 
     override val context: Context get() = snark.context
 
+    /**
+     * Site configuration
+     */
     public val siteMeta: Meta
 
-    public fun assetFile(remotePath: String, file: Path)
+    /**
+     * Add a static file or directory to this site/route at [remotePath]
+     */
+    public fun file(file: Path, remotePath: String = file.fileName.toString())
 
-    public fun assetDirectory(remotePath: String, directory: Path)
+    /**
+     * Add a static file (single) from resources
+     */
+    public fun resourceFile(remotePath: String, resourcesPath: String)
 
-    public fun assetResourceFile(remotePath: String, resourcesPath: String)
+    /**
+     * Add a resource directory to route
+     */
+    public fun resourceDirectory(resourcesPath: String)
 
-    public fun assetResourceDirectory(resourcesPath: String)
+    /**
-
+     * Create a single page at given [route]. If route is empty, create an index page at current route.
-    public fun page(route: Name = Name.EMPTY, content: context(Page, HTML) () -> Unit)
+     */
+    public fun page(route: Name = Name.EMPTY, content: context(WebPage, HTML) () -> Unit)
 
     /**
      * Create a route with optional data tree override. For example one could use a subtree of the initial tree.
-     * By default, the same data tree is used for route
+     * By default, the same data tree is used for route.
      */
     public fun route(
         routeName: Name,
@@ -90,11 +106,4 @@ public inline fun SiteBuilder.route(
 //    route(route) {
 //        withData(mountedData).block()
 //    }
-//}
+//}
-
-//TODO move to DF
-public fun DataTree.Companion.empty(meta: Meta = Meta.EMPTY): DataTree<Any> = object : DataTree<Any> {
-    override val items: Map<NameToken, DataTreeItem<Any>> get() = emptyMap()
-    override val dataType: KType get() = typeOf<Any>()
-    override val meta: Meta get() = meta
-}

snark-html/src/main/kotlin/space/kscience/snark/html/SiteLayout.kt

@@ -30,27 +30,30 @@ internal fun SiteBuilder.assetsFrom(rootMeta: Meta) {
         path?.let { resourcePath ->
             //If remote path provided, use a single resource
             remotePath?.let {
-                assetResourceFile(it, resourcePath)
+                resourceFile(it, resourcePath)
                 return@forEach
             }
 
             //otherwise use package resources
-            assetResourceDirectory(resourcePath)
+            resourceDirectory(resourcePath)
         }
     }
 
     rootMeta.getIndexed("file".asName()).forEach { (_, meta) ->
         val remotePath by meta.string { error("File remote path is not provided") }
         val path by meta.string { error("File path is not provided") }
-        assetFile(remotePath, Path.of(path))
+        file(Path.of(path), remotePath)
     }
 
     rootMeta.getIndexed("directory".asName()).forEach { (_, meta) ->
         val path by meta.string { error("Directory path is not provided") }
-        assetDirectory("", Path.of(path))
+        file(Path.of(path), "")
     }
 }
 
+/**
+ * Render (or don't) given data piece
+ */
 public typealias DataRenderer = SiteBuilder.(name: Name, data: Data<Any>) -> Unit
 
 /**
@@ -114,7 +117,9 @@ public fun SiteBuilder.pages(
     pages(dataPath.parseAsName(), remotePath, dataRenderer = dataRenderer)
 }
 
-
+/**
+ * An abstraction to render singular data or a data tree.
+ */
 @Type(SiteLayout.TYPE)
 public fun interface SiteLayout {
 
@@ -142,7 +147,9 @@ public fun interface SiteLayout {
     }
 }
 
-
+/**
+ * The default [SiteLayout]. It renders all [HtmlData] pages as t with simple headers via [SiteLayout.defaultDataRenderer]
+ */
 public object DefaultSiteLayout : SiteLayout {
     context(SiteBuilder) override fun render(item: DataTreeItem<*>) {
         pages(item)

snark-html/src/main/kotlin/space/kscience/snark/html/SnarkHtmlPlugin.kt

@@ -3,7 +3,9 @@ package space.kscience.snark.html
 import io.ktor.utils.io.core.readBytes
 import space.kscience.dataforge.context.*
 import space.kscience.dataforge.data.DataTree
-import space.kscience.dataforge.io.*
+import space.kscience.dataforge.io.IOPlugin
+import space.kscience.dataforge.io.IOReader
+import space.kscience.dataforge.io.JsonMetaFormat
 import space.kscience.dataforge.io.yaml.YamlMetaFormat
 import space.kscience.dataforge.io.yaml.YamlPlugin
 import space.kscience.dataforge.meta.Meta
@@ -15,32 +17,16 @@ import space.kscience.dataforge.names.asName
 import space.kscience.dataforge.names.parseAsName
 import space.kscience.dataforge.workspace.FileData
 import space.kscience.dataforge.workspace.readDataDirectory
+import space.kscience.snark.SnarkEnvironment
 import space.kscience.snark.SnarkParser
 import java.nio.file.Path
 import kotlin.io.path.extension
 import kotlin.reflect.KClass
-import kotlin.reflect.KType
-import kotlin.reflect.typeOf
-
-@PublishedApi
-internal class SnarkParserWrapper<R : Any>(
-    val reader: IOReader<R>,
-    override val type: KType,
-    override val fileExtensions: Set<String>,
-) : SnarkParser<R> {
-    override fun parse(context: Context, meta: Meta, bytes: ByteArray): R = bytes.asBinary().readWith(reader)
-}
 
 /**
- * Create a generic parser from reader
+ * A plugin used for rendering a [DataTree] as HTML
  */
-@Suppress("FunctionName")
+public class SnarkHtmlPlugin : AbstractPlugin() {
-public inline fun <reified R : Any> SnarkParser(
-    reader: IOReader<R>,
-    vararg fileExtensions: String,
-): SnarkParser<R> = SnarkParserWrapper(reader, typeOf<R>(), fileExtensions.toSet())
-
-public class SnarkPlugin : AbstractPlugin() {
     private val yaml by require(YamlPlugin)
     public val io: IOPlugin get() = yaml.io
 
@@ -54,8 +40,8 @@ public class SnarkPlugin : AbstractPlugin() {
         context.gather(SiteLayout.TYPE, true)
     }
 
-    private val textTransformations: Map<Name, TextTransformation> by lazy {
+    private val textProcessors: Map<Name, TextProcessor> by lazy {
-        context.gather(TextTransformation.TYPE, true)
+        context.gather(TextProcessor.TYPE, true)
     }
 
     internal fun siteLayout(layoutMeta: Meta): SiteLayout {
@@ -64,10 +50,10 @@ public class SnarkPlugin : AbstractPlugin() {
         return siteLayouts[layoutName.parseAsName()] ?: error("Layout with name $layoutName not found in $this")
     }
 
-    internal fun textTransformation(transformationMeta: Meta): TextTransformation {
+    internal fun textProcessor(transformationMeta: Meta): TextProcessor {
         val transformationName = transformationMeta.string
             ?: transformationMeta["name"].string ?: error("Transformation name not defined in $transformationMeta")
-        return textTransformations[transformationName.parseAsName()]
+        return textProcessors[transformationName.parseAsName()]
             ?: error("Text transformation with name $transformationName not found in $this")
     }
 
@@ -81,17 +67,17 @@ public class SnarkPlugin : AbstractPlugin() {
             "jpg".asName() to SnarkParser(ImageIOReader, "jpg", "jpeg"),
             "gif".asName() to SnarkParser(ImageIOReader, "gif"),
         )
-        TextTransformation.TYPE -> mapOf(
+        TextProcessor.TYPE -> mapOf(
-            "basic".asName() to BasicTextTransformation
+            "basic".asName() to BasicTextProcessor
         )
         else -> super.content(target)
     }
 
-    public companion object : PluginFactory<SnarkPlugin> {
+    public companion object : PluginFactory<SnarkHtmlPlugin> {
         override val tag: PluginTag = PluginTag("snark")
-        override val type: KClass<out SnarkPlugin> = SnarkPlugin::class
+        override val type: KClass<out SnarkHtmlPlugin> = SnarkHtmlPlugin::class
 
-        override fun build(context: Context, meta: Meta): SnarkPlugin = SnarkPlugin()
+        override fun build(context: Context, meta: Meta): SnarkHtmlPlugin = SnarkHtmlPlugin()
 
         private val byteArrayIOReader = IOReader {
             readBytes()
@@ -101,8 +87,21 @@ public class SnarkPlugin : AbstractPlugin() {
     }
 }
 
+/**
+ * Load necessary dependencies and return a [SnarkHtmlPlugin] in a finalized context
+ */
+public fun SnarkEnvironment.buildHtmlPlugin(): SnarkHtmlPlugin {
+    val context = parentContext.buildContext("snark".asName()) {
+        plugin(SnarkHtmlPlugin)
+        plugins.forEach {
+            plugin(it)
+        }
+    }
+    return context.fetch(SnarkHtmlPlugin)
+}
+
 @OptIn(DFExperimental::class)
-public fun SnarkPlugin.readDirectory(path: Path): DataTree<Any> = io.readDataDirectory(path) { dataPath, meta ->
+public fun SnarkHtmlPlugin.readDirectory(path: Path): DataTree<Any> = io.readDataDirectory(path) { dataPath, meta ->
     val fileExtension = meta[FileData.META_FILE_EXTENSION_KEY].string ?: dataPath.extension
     val parser: SnarkParser<Any> = parsers.values.filter { parser ->
         fileExtension in parser.fileExtensions
@@ -110,7 +109,7 @@ public fun SnarkPlugin.readDirectory(path: Path): DataTree<Any> = io.readDataDir
         it.priority
     } ?: run {
         logger.warn { "The parser is not found for file $dataPath with meta $meta" }
-        SnarkPlugin.byteArraySnarkParser
+        SnarkHtmlPlugin.byteArraySnarkParser
     }
 
     parser.reader(context, meta)

snark-html/src/main/kotlin/space/kscience/snark/html/SnarkTextParser.kt

@@ -23,9 +23,9 @@ public abstract class SnarkTextParser<R> : SnarkParser<R> {
     override fun parse(context: Context, meta: Meta, bytes: ByteArray): R =
         parseText(bytes.decodeToString(), meta)
 
-    public fun transformText(text: String, meta: Meta, page: Page): String =
+    public fun transformText(text: String, meta: Meta, page: WebPage): String =
-        meta[TextTransformation.TEXT_TRANSFORMATION_KEY]?.let {
+        meta[TextProcessor.TEXT_TRANSFORMATION_KEY]?.let {
-            with(page) { page.snark.textTransformation(it).transform(text) }
+            with(page) { page.snark.textProcessor(it).process(text) }
         } ?: text
 }
 

snark-html/src/main/kotlin/space/kscience/snark/html/StaticSiteBuilder.kt

@@ -8,6 +8,7 @@ import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.withDefault
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.isEmpty
+import space.kscience.snark.SnarkEnvironment
 import java.nio.file.Files
 import java.nio.file.Path
 import kotlin.contracts.InvocationKind
@@ -15,12 +16,15 @@ import kotlin.contracts.contract
 import kotlin.io.path.*
 
 
+/**
+ * An implementation of [SiteBuilder] to render site as a static directory [outputPath]
+ */
 internal class StaticSiteBuilder(
-    override val snark: SnarkPlugin,
+    override val snark: SnarkHtmlPlugin,
     override val data: DataTree<*>,
     override val siteMeta: Meta,
     private val baseUrl: String,
-    private val path: Path,
+    private val outputPath: Path,
 ) : SiteBuilder {
     private fun Path.copyRecursively(target: Path) {
         Files.walk(this).forEach { source: Path ->
@@ -32,27 +36,28 @@ internal class StaticSiteBuilder(
         }
     }
 
-    override fun assetFile(remotePath: String, file: Path) {
+    override fun file(file: Path, remotePath: String) {
-        val targetPath = path.resolve(remotePath)
+        val targetPath = outputPath.resolve(remotePath)
-        targetPath.parent.createDirectories()
+        if(file.isDirectory()){
-        file.copyTo(targetPath, true)
+            targetPath.parent.createDirectories()
+            file.copyRecursively(targetPath)
+        } else if(remotePath.isBlank()) {
+            error("Can't mount file to an empty route")
+        } else {
+            targetPath.parent.createDirectories()
+            file.copyTo(targetPath, true)
+        }
     }
 
-    override fun assetDirectory(remotePath: String, directory: Path) {
+    override fun resourceFile(remotePath: String, resourcesPath: String) {
-        val targetPath = path.resolve(remotePath)
+        val targetPath = outputPath.resolve(remotePath)
-        targetPath.parent.createDirectories()
-        directory.copyRecursively(targetPath)
-    }
-
-    override fun assetResourceFile(remotePath: String, resourcesPath: String) {
-        val targetPath = path.resolve(remotePath)
         targetPath.parent.createDirectories()
         javaClass.getResource(resourcesPath)?.let { Path.of(it.toURI()) }?.copyTo(targetPath, true)
     }
 
-    override fun assetResourceDirectory(resourcesPath: String) {
+    override fun resourceDirectory(resourcesPath: String) {
-        path.parent.createDirectories()
+        outputPath.parent.createDirectories()
-        javaClass.getResource(resourcesPath)?.let { Path.of(it.toURI()) }?.copyRecursively(path)
+        javaClass.getResource(resourcesPath)?.let { Path.of(it.toURI()) }?.copyRecursively(outputPath)
     }
 
     private fun resolveRef(baseUrl: String, ref: String) = if (baseUrl.isEmpty()) {
@@ -63,10 +68,10 @@ internal class StaticSiteBuilder(
         "${baseUrl.removeSuffix("/")}/$ref"
     }
 
-    inner class StaticPage : Page {
+    inner class StaticWebPage : WebPage {
         override val data: DataTree<*> get() = this@StaticSiteBuilder.data
         override val pageMeta: Meta get() = this@StaticSiteBuilder.siteMeta
-        override val snark: SnarkPlugin get() = this@StaticSiteBuilder.snark
+        override val snark: SnarkHtmlPlugin get() = this@StaticSiteBuilder.snark
 
 
         override fun resolveRef(ref: String): String = resolveRef(baseUrl, ref)
@@ -77,17 +82,17 @@ internal class StaticSiteBuilder(
     }
 
 
-    override fun page(route: Name, content: context(Page, HTML) () -> Unit) {
+    override fun page(route: Name, content: context(WebPage, HTML) () -> Unit) {
         val htmlBuilder = createHTML()
 
         htmlBuilder.html {
-            content(StaticPage(), this)
+            content(StaticWebPage(), this)
         }
 
         val newPath = if (route.isEmpty()) {
-            path.resolve("index.html")
+            outputPath.resolve("index.html")
         } else {
-            path.resolve(route.toWebPath() + ".html")
+            outputPath.resolve(route.toWebPath() + ".html")
         }
 
         newPath.parent.createDirectories()
@@ -108,18 +113,23 @@ internal class StaticSiteBuilder(
         } else {
             baseUrl
         },
-        path = path.resolve(routeName.toWebPath())
+        outputPath = outputPath.resolve(routeName.toWebPath())
     )
 }
 
-public fun SnarkPlugin.renderStatic(
+/**
+ * Create a static site using given [data] in provided [outputPath].
+ * Use [siteUrl] as a base for all resolved URLs. By default, use [outputPath] absolute path as a base.
+ *
+ */
+public fun SnarkEnvironment.static(
     outputPath: Path,
-    data: DataTree<*> = DataTree.empty(),
     siteUrl: String = outputPath.absolutePathString().replace("\\", "/"),
     block: SiteBuilder.() -> Unit,
 ) {
     contract {
         callsInPlace(block, InvocationKind.EXACTLY_ONCE)
     }
-    StaticSiteBuilder(this, data, meta, siteUrl, outputPath).block()
+    val plugin = buildHtmlPlugin()
+    StaticSiteBuilder(plugin, data, meta, siteUrl, outputPath).block()
 }

snark-html/src/main/kotlin/space/kscience/snark/html/TextProcessor.kt

@@ -0,0 +1,56 @@
+package space.kscience.snark.html
+
+import space.kscience.dataforge.meta.get
+import space.kscience.dataforge.meta.string
+import space.kscience.dataforge.misc.Type
+import space.kscience.dataforge.names.NameToken
+import space.kscience.dataforge.names.parseAsName
+
+/**
+ * An object that conducts page-based text transformation. Like using link replacement or templating.
+ */
+@Type(TextProcessor.TYPE)
+public fun interface TextProcessor {
+    context(WebPage) public fun process(text: String): String
+
+    public companion object {
+        public const val TYPE: String = "snark.textTransformation"
+        public val TEXT_TRANSFORMATION_KEY: NameToken = NameToken("transformation")
+    }
+}
+
+/**
+ * A basic [TextProcessor] that replaces `${...}` expressions in text. The following expressions are recognised:
+ * * `homeRef` resolves to [homeRef]
+ * * `resolveRef("...")` -> [WebPage.resolveRef]
+ * * `resolvePageRef("...")` -> [WebPage.resolvePageRef]
+ * * `pageMeta.get("...") -> [WebPage.pageMeta] get string method
+ * Otherwise return unchanged string
+ */
+public object BasicTextProcessor : TextProcessor {
+
+    private val regex = """\$\{([\w.]*)(?>\("([\w.]*)"\))?}""".toRegex()
+
+    context(WebPage) override fun process(text: String): String = text.replace(regex) { match ->
+        when (match.groups[1]!!.value) {
+            "homeRef" -> homeRef
+            "resolveRef" -> {
+                val refString = match.groups[2]?.value ?: error("resolveRef requires a string (quoted) argument")
+                resolveRef(refString)
+            }
+            "resolvePageRef" -> {
+                val refString = match.groups[2]?.value
+                    ?: error("resolvePageRef requires a string (quoted) argument")
+                resolvePageRef(refString)
+            }
+            "pageMeta.get" -> {
+                val nameString = match.groups[2]?.value
+                    ?: error("resolvePageRef requires a string (quoted) argument")
+                pageMeta[nameString.parseAsName()].string ?: "@null"
+            }
+            else -> match.value
+        }
+    }
+}
+
+

snark-html/src/main/kotlin/space/kscience/snark/html/TextTransformation.kt

@@ -1,38 +0,0 @@
-package space.kscience.snark.html
-
-import space.kscience.dataforge.misc.Type
-import space.kscience.dataforge.names.NameToken
-
-@Type(TextTransformation.TYPE)
-public fun interface TextTransformation {
-    context(Page) public fun transform(text: String): String
-
-    public companion object {
-        public const val TYPE: String = "snark.textTransformation"
-        public val TEXT_TRANSFORMATION_KEY: NameToken = NameToken("transformation")
-    }
-}
-
-public object BasicTextTransformation : TextTransformation {
-
-    private val regex = "\\\$\\{(\\w*)(?>\\(\"(.*)\"\\))?\\}".toRegex()
-
-    context(Page) override fun transform(text: String): String {
-        return text.replace(regex) { match ->
-            when (match.groups[1]!!.value) {
-                "homeRef" -> homeRef
-                "resolveRef" -> {
-                    val refString = match.groups[2]?.value ?: error("resolveRef requires a string (quoted) argument")
-                    resolveRef(refString)
-                }
-                "resolvePageRef" -> {
-                    val refString = match.groups[2]?.value ?: error("resolvePageRef requires a string (quoted) argument")
-                    resolvePageRef(refString)
-                }
-                else -> match.value
-            }
-        }
-    }
-}
-
-

snark-html/src/main/kotlin/space/kscience/snark/html/WebPage.kt

@@ -17,9 +17,9 @@ context(SnarkContext) public fun Name.toWebPath(): String = tokens.joinToString(
     }
 }
 
-public interface Page : ContextAware, SnarkContext {
+public interface WebPage : ContextAware, SnarkContext {
 
-    public val snark: SnarkPlugin
+    public val snark: SnarkHtmlPlugin
 
     override val context: Context get() = snark.context
 
@@ -32,11 +32,11 @@ public interface Page : ContextAware, SnarkContext {
     public fun resolvePageRef(pageName: Name): String
 }
 
-context(Page) public val page: Page get() = this@Page
+context(WebPage) public val page: WebPage get() = this@WebPage
 
-public fun Page.resolvePageRef(pageName: String): String = resolvePageRef(pageName.parseAsName())
+public fun WebPage.resolvePageRef(pageName: String): String = resolvePageRef(pageName.parseAsName())
 
-public val Page.homeRef: String get() = resolvePageRef(SiteBuilder.INDEX_PAGE_TOKEN.asName())
+public val WebPage.homeRef: String get() = resolvePageRef(SiteBuilder.INDEX_PAGE_TOKEN.asName())
 
 /**
  * Resolve a Html builder by its full name

snark-html/src/main/kotlin/space/kscience/snark/html/htmlEnvironment.kt

@@ -0,0 +1,42 @@
+package space.kscience.snark.html
+
+import space.kscience.dataforge.context.AbstractPlugin
+import space.kscience.dataforge.context.PluginTag
+import space.kscience.dataforge.data.DataTreeItem
+import space.kscience.dataforge.names.Name
+import space.kscience.dataforge.names.parseAsName
+import space.kscience.snark.SnarkEnvironment
+import kotlin.contracts.InvocationKind
+import kotlin.contracts.contract
+
+public class SnarkHtmlEnvironmentBuilder {
+    public val layouts: HashMap<Name, SiteLayout> = HashMap()
+
+    public fun layout(name: String, body: context(SiteBuilder) (DataTreeItem<*>) -> Unit) {
+        layouts[name.parseAsName()] = object : SiteLayout {
+            context(SiteBuilder) override fun render(item: DataTreeItem<*>) = body(siteBuilder, item)
+        }
+    }
+}
+
+
+public fun SnarkEnvironment.html(block: SnarkHtmlEnvironmentBuilder.() -> Unit) {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
+
+    val envBuilder = SnarkHtmlEnvironmentBuilder().apply(block)
+
+    val plugin = object : AbstractPlugin() {
+        val snark by require(SnarkHtmlPlugin)
+
+        override val tag: PluginTag = PluginTag("@extension[${hashCode()}]")
+
+
+        override fun content(target: String): Map<Name, Any> = when (target) {
+            SiteLayout.TYPE -> envBuilder.layouts
+            else -> super.content(target)
+        }
+    }
+    registerPlugin(plugin)
+}

snark-ktor/src/main/kotlin/space/kscience/snark/ktor/KtorSiteBuilder.kt

@@ -20,27 +20,32 @@ import space.kscience.dataforge.meta.withDefault
 import space.kscience.dataforge.names.Name
 import space.kscience.dataforge.names.cutLast
 import space.kscience.dataforge.names.endsWith
+import space.kscience.snark.SnarkEnvironment
 import space.kscience.snark.html.*
 import java.nio.file.Path
 import kotlin.contracts.InvocationKind
 import kotlin.contracts.contract
+import kotlin.io.path.isDirectory
 
 @PublishedApi
 internal class KtorSiteBuilder(
-    override val snark: SnarkPlugin,
+    override val snark: SnarkHtmlPlugin,
     override val data: DataTree<*>,
     override val siteMeta: Meta,
     private val baseUrl: String,
     private val ktorRoute: Route,
 ) : SiteBuilder {
 
-    override fun assetFile(remotePath: String, file: Path) {
+    override fun file(file: Path, remotePath: String) {
-        ktorRoute.file(remotePath, file.toFile())
+        if (file.isDirectory()) {
-    }
+            ktorRoute.static(remotePath) {
-
+                //TODO check non-standard FS and convert
-    override fun assetDirectory(remotePath: String, directory: Path) {
+                files(file.toFile())
-        ktorRoute.static(remotePath) {
+            }
-            files(directory.toFile())
+        } else if (remotePath.isBlank()) {
+            error("Can't mount file to an empty route")
+        } else {
+            ktorRoute.file(remotePath, file.toFile())
         }
     }
 
@@ -53,11 +58,11 @@ internal class KtorSiteBuilder(
     }
 
 
-    inner class KtorPage(
+    inner class KtorWebPage(
         val pageBaseUrl: String,
         override val pageMeta: Meta = this@KtorSiteBuilder.siteMeta,
-    ) : Page {
+    ) : WebPage {
-        override val snark: SnarkPlugin get() = this@KtorSiteBuilder.snark
+        override val snark: SnarkHtmlPlugin get() = this@KtorSiteBuilder.snark
         override val data: DataTree<*> get() = this@KtorSiteBuilder.data
 
         override fun resolveRef(ref: String): String = resolveRef(pageBaseUrl, ref)
@@ -69,7 +74,7 @@ internal class KtorSiteBuilder(
         }
     }
 
-    override fun page(route: Name, content: context(Page, HTML)() -> Unit) {
+    override fun page(route: Name, content: context(WebPage, HTML)() -> Unit) {
         ktorRoute.get(route.toWebPath()) {
             call.respondHtml {
                 val request = call.request
@@ -79,7 +84,7 @@ internal class KtorSiteBuilder(
                     host = request.host()
                     port = request.port()
                 }
-                val pageBuilder = KtorPage(url.buildString())
+                val pageBuilder = KtorWebPage(url.buildString())
                 content(pageBuilder, this)
             }
         }
@@ -103,34 +108,31 @@ internal class KtorSiteBuilder(
     )
 
 
-    override fun assetResourceFile(remotePath: String, resourcesPath: String) {
+    override fun resourceFile(remotePath: String, resourcesPath: String) {
         ktorRoute.resource(resourcesPath, resourcesPath)
     }
 
-    override fun assetResourceDirectory(resourcesPath: String) {
+    override fun resourceDirectory(resourcesPath: String) {
         ktorRoute.resources(resourcesPath)
     }
 }
 
-public inline fun Route.snarkSite(
+context(Route, SnarkEnvironment) public fun siteInRoute(
-    snark: SnarkPlugin,
-    data: DataTree<*>,
-    meta: Meta = data.meta,
     block: SiteBuilder.() -> Unit,
 ) {
     contract {
         callsInPlace(block, InvocationKind.EXACTLY_ONCE)
     }
-    block(KtorSiteBuilder(snark, data, meta, "", this@snarkSite))
+    block(KtorSiteBuilder(buildHtmlPlugin(), data, meta, "", this@Route))
 }
 
-public fun Application.snarkSite(
+context(Application) public fun SnarkEnvironment.site(
-    snark: SnarkPlugin,
-    data: DataTree<*> = DataTree.empty(),
-    meta: Meta = data.meta,
     block: SiteBuilder.() -> Unit,
 ) {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
     routing {
-        snarkSite(snark, data, meta, block)
+        siteInRoute(block)
     }
 }