Fully working document processing

examples/document/data/loremIpsum/chapter1.md

@@ -1,9 +1,8 @@
 ---
-type: markdown
+contentType: markdown
-order: 1
 ---
 
-# ${documentName}
+Document name: ${documentName}
 
 ${documentMeta.metaValue}
 

examples/document/data/loremIpsum/chapter3.md

@@ -1,6 +1,5 @@
 ---
-type: markdown
+contentType: markdown
-order: 3
 ---
 
 ## Chapter ${section(1)}

examples/document/data/loremIpsum/document.yaml

@@ -0,0 +1,14 @@
+route: lorem.ipsum
+title: Lorem Ipsum
+authors:
+  - name: Alexander Nozik
+    affiliation: MIPT
+fragments:
+  - name: chapter1
+    type: data
+  - name: chapter2
+    type: data
+  - name: chapter3
+    type: data
+documentMeta:
+  metaValue: Hello world!

examples/document/src/jvmMain/kotlin/main.kt

@@ -1,24 +1,42 @@
 import io.ktor.server.application.Application
 import io.ktor.server.cio.CIO
 import io.ktor.server.engine.embeddedServer
-import space.kscience.dataforge.meta.Meta
+import kotlinx.html.ScriptCrossorigin
-import space.kscience.dataforge.names.asName
+import kotlinx.html.link
-import space.kscience.snark.html.document.document
+import kotlinx.html.script
-import space.kscience.snark.html.document.fragment
+import space.kscience.snark.html.document.allDocuments
 
 @Suppress("unused")
-fun Application.documents() = snarkApplication {
+fun Application.renderAllDocuments() = snarkApplication {
-    document("loremIpsum".asName(), Meta { "metaValue" put "Hello world!" }) {
+    allDocuments(
-        fragment("chapter1")
+        headers = {
-        fragment("chapter2")
+            link {
-        fragment("chapter3")
+                rel = "stylesheet"
-    }
+                href = "https://cdn.jsdelivr.net/npm/katex@0.16.10/dist/katex.min.css"
+                attributes["integrity"] = "sha384-wcIxkf4k558AjM3Yz3BBFQUbk/zgIYC2R0QpeeYb+TwlBVMrlgLqwRjRtGZiK7ww"
+                attributes["crossorigin"] = "anonymous"
+            }
+            script {
+                defer = true
+                src = "https://cdn.jsdelivr.net/npm/katex@0.16.10/dist/katex.min.js"
+                integrity = "sha384-hIoBPJpTUs74ddyc4bFZSM1TVlQDA60VBbJS0oA934VSz82sBx1X7kSx2ATBDIyd"
+                crossorigin = ScriptCrossorigin.anonymous
+            }
+            script {
+                defer = true
+                src = "https://cdn.jsdelivr.net/npm/katex@0.16.10/dist/contrib/auto-render.min.js"
+                integrity = "sha384-43gviWU0YVjaDtb/GhzOouOXtZMP/7XUzwPTstBeZFe/+rCMvRwr4yROQP43s0Xk"
+                crossorigin = ScriptCrossorigin.anonymous
+                attributes["onload"] = "renderMathInElement(document.body);"
+            }
+        }
+    )
 }
 
 
 fun main() {
 
     embeddedServer(CIO) {
-        documents()
+        renderAllDocuments()
     }.start(true)
 }

examples/document/src/jvmMain/kotlin/snarkApplication.kt

@@ -1,5 +1,6 @@
 import io.ktor.server.application.Application
 import io.ktor.server.application.log
+import io.ktor.server.http.content.staticResources
 import io.ktor.server.routing.routing
 import space.kscience.dataforge.context.Context
 import space.kscience.dataforge.context.ContextBuilder
@@ -42,6 +43,7 @@ fun Application.snarkApplication(contextBuilder: ContextBuilder.() -> Unit = {},
     }
 
     routing {
+        staticResources("/css","css")
         site(context, siteData, content = site)
     }
 }

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

@@ -15,12 +15,12 @@ import kotlin.reflect.typeOf
 public class ReWrapAction<R : Any>(
     type: KType,
     private val newMeta: MutableMeta.(name: Name) -> Unit = {},
-    private val newName: (name: Name, meta: Meta?) -> Name,
+    private val newName: (name: Name, meta: Meta?, type: KType) -> Name,
 ) : AbstractAction<R, R>(type) {
     override fun DataSink<R>.generate(data: DataTree<R>, meta: Meta) {
         data.forEach { namedData ->
             put(
-                newName(namedData.name, namedData.meta),
+                newName(namedData.name, namedData.meta, namedData.type),
                 namedData.data.withMeta(namedData.meta.copy { newMeta(namedData.name) })
             )
         }
@@ -28,34 +28,19 @@ public class ReWrapAction<R : Any>(
 
     override fun DataSink<R>.update(source: DataTree<R>, meta: Meta, namedData: NamedData<R>) {
         put(
-            newName(namedData.name, namedData.meta),
+            newName(namedData.name, namedData.meta, namedData.type),
             namedData.withMeta(namedData.meta.copy { newMeta(namedData.name) })
         )
     }
 
     public companion object {
-        public inline fun <reified R : Any> removeExtensions(
-            vararg bypassExtensions: String,
-            noinline newMeta: MutableMeta.(name: Name) -> Unit = {},
-        ): ReWrapAction<R> = ReWrapAction(typeOf<R>(), newMeta = newMeta) { name, _ ->
-            name.replaceLast { token ->
-                val extension = token.body.substringAfterLast('.')
-                if (extension in bypassExtensions) {
-                    NameToken(token.body.removeSuffix(".$extension"))
-                } else {
-                    token
-                }
-            }
-        }
 
-        public inline fun <reified R : Any> removeIndex(): ReWrapAction<R> = ReWrapAction<R>(typeOf<R>()) { name, _ ->
+
-            if (name.endsWith("index")) name.cutLast() else name
-        }
     }
 }
 
 public inline fun <reified R : Any> ReWrapAction(
     noinline newMeta: MutableMeta.(name: Name) -> Unit = {},
-    noinline newName: (Name, Meta?) -> Name,
+    noinline newName: (Name, Meta?, type: KType) -> Name,
 ): ReWrapAction<R> = ReWrapAction(typeOf<R>(), newMeta, newName)
 

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

@@ -5,10 +5,13 @@ import space.kscience.dataforge.io.asBinary
 import space.kscience.dataforge.misc.DfType
 import space.kscience.snark.SnarkReader.Companion.DEFAULT_PRIORITY
 import space.kscience.snark.SnarkReader.Companion.DF_TYPE
+import kotlin.reflect.KType
+import kotlin.reflect.typeOf
 
 @DfType(DF_TYPE)
 public interface SnarkReader<out T> : IOReader<T> {
-    public val types: Set<String>
+    public val outputType: KType
+    public val inputContentTypes: Set<String>
     public val priority: Int get() = DEFAULT_PRIORITY
     public fun readFrom(source: String): T
 
@@ -23,13 +26,14 @@ public interface SnarkReader<out T> : IOReader<T> {
  *
  * @param T The type of data to be read by the IOReader.
  * @property reader The underlying IOReader instance used for reading data.
- * @property types The set of supported types that can be read by the SnarkIOReader.
+ * @property inputContentTypes The set of supported types that can be read by the SnarkIOReader.
  * @property priority The priority of the SnarkIOReader. Higher priority SnarkIOReader instances will be preferred over lower priority ones.
  */
 
 private class SnarkReaderWrapper<out T>(
     private val reader: IOReader<T>,
-    override val types: Set<String>,
+    override val outputType: KType,
+    override val inputContentTypes: Set<String>,
     override val priority: Int = DEFAULT_PRIORITY,
 ) : IOReader<T> by reader, SnarkReader<T> {
 
@@ -38,6 +42,14 @@ private class SnarkReaderWrapper<out T>(
 
 public fun <T : Any> SnarkReader(
     reader: IOReader<T>,
-    vararg types: String,
+    outputType: KType,
+    vararg inputContentTypes: String,
     priority: Int = DEFAULT_PRIORITY,
-): SnarkReader<T> = SnarkReaderWrapper(reader, types.toSet(), priority)
+): SnarkReader<T> = SnarkReaderWrapper(reader, outputType, inputContentTypes.toSet(), priority)
+
+
+public inline fun <reified T : Any> SnarkReader(
+    reader: IOReader<T>,
+    vararg inputContentTypes: String,
+    priority: Int = DEFAULT_PRIORITY,
+): SnarkReader<T> = SnarkReader(reader, typeOf<T>(), inputContentTypes = inputContentTypes, priority)

snark-html/build.gradle.kts

@@ -8,6 +8,7 @@ val ktorVersion = space.kscience.gradle.KScienceVersions.ktorVersion
 
 kscience{
     jvm()
+    useSerialization()
     useContextReceivers()
     commonMain{
         api(projects.snarkCore)

snark-html/src/jvmMain/kotlin/space/kscience/snark/html/MarkdownReader.kt

@@ -71,7 +71,7 @@ public object SnarkFlavorDescriptor : GFMFlavourDescriptor(false) {
 }
 
 public object MarkdownReader : SnarkHtmlReader {
-    override val types: Set<String> = setOf("text/markdown", "md", "markdown")
+    override val inputContentTypes: Set<String> = setOf("text/markdown", "md", "markdown")
 
     override fun readFrom(source: String): PageFragment = PageFragment {
         val parsedTree = markdownParser.parse(IElementType("ROOT"), source)
@@ -88,7 +88,4 @@ public object MarkdownReader : SnarkHtmlReader {
     private val markdownParser = MarkdownParser(markdownFlavor)
 
     override fun readFrom(source: Source): PageFragment = readFrom(source.readString())
-
-    public val snarkReader: SnarkReader<PageFragment> = SnarkReader(this, "text/markdown")
-
 }

snark-html/src/jvmMain/kotlin/space/kscience/snark/html/ParseAction.kt

@@ -6,17 +6,35 @@ import space.kscience.dataforge.io.Binary
 import space.kscience.dataforge.io.toByteArray
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.get
+import space.kscience.dataforge.misc.DFInternal
+import space.kscience.snark.SnarkReader
 import space.kscience.snark.TextProcessor
+import kotlin.coroutines.CoroutineContext
+import kotlin.coroutines.EmptyCoroutineContext
+import kotlin.reflect.KType
 import kotlin.reflect.typeOf
 
-public class ParseAction(private val snarkHtml: SnarkHtml) :
+@OptIn(DFInternal::class)
-    AbstractAction<Binary, PageFragment>(typeOf<PageFragment>()) {
+internal fun <T, R> Data<T>.transform(
+    type: KType,
+    meta: Meta = this.meta,
+    coroutineContext: CoroutineContext = EmptyCoroutineContext,
+    block: suspend (T) -> R,
+): Data<R> {
+    val data = Data(type, meta, coroutineContext, listOf(this)) {
+        block(await())
+    }
+    return data
+}
 
-    private fun parseOne(data: NamedData<Binary>): NamedData<PageFragment>? = with(snarkHtml) {
+public class ParseAction(private val snarkHtml: SnarkHtml) :
+    AbstractAction<Binary, Any>(typeOf<PageFragment>()) {
+
+    private fun parseOne(data: NamedData<Binary>): NamedData<Any>? = with(snarkHtml) {
         val contentType = getContentType(data.name, data.meta)
 
-        val parser = snark.readers.values.filterIsInstance<SnarkHtmlReader>().filter { parser ->
+        val parser: SnarkReader<Any>? = snark.readers.values.filter { parser ->
-            contentType in parser.types
+            contentType in parser.inputContentTypes
         }.maxByOrNull {
             it.priority
         }
@@ -24,7 +42,7 @@ public class ParseAction(private val snarkHtml: SnarkHtml) :
         //ignore data for which parser is not found
         if (parser != null) {
             val preprocessor = meta[TextProcessor.TEXT_PREPROCESSOR_KEY]?.let { snark.preprocessor(it) }
-            data.transform {
+            data.transform(parser.outputType) {
                 if (preprocessor == null) {
                     parser.readFrom(it)
                 } else {
@@ -38,13 +56,13 @@ public class ParseAction(private val snarkHtml: SnarkHtml) :
         }
     }
 
-    override fun DataSink<PageFragment>.generate(data: DataTree<Binary>, meta: Meta) {
+    override fun DataSink<Any>.generate(data: DataTree<Binary>, meta: Meta) {
         data.forEach {
             parseOne(it)?.let { put(it) }
         }
     }
 
-    override fun DataSink<PageFragment>.update(source: DataTree<Binary>, meta: Meta, namedData: NamedData<Binary>) {
+    override fun DataSink<Any>.update(source: DataTree<Binary>, meta: Meta, namedData: NamedData<Binary>) {
         parseOne(namedData)?.let { put(it) }
     }
 }

snark-html/src/jvmMain/kotlin/space/kscience/snark/html/SnarkHtml.kt

@@ -22,8 +22,7 @@ import space.kscience.dataforge.meta.get
 import space.kscience.dataforge.meta.set
 import space.kscience.dataforge.meta.string
 import space.kscience.dataforge.misc.DFExperimental
-import space.kscience.dataforge.names.Name
+import space.kscience.dataforge.names.*
-import space.kscience.dataforge.names.asName
 import space.kscience.dataforge.provider.dfType
 import space.kscience.dataforge.workspace.*
 import space.kscience.snark.ReWrapAction
@@ -33,6 +32,7 @@ import space.kscience.snark.TextProcessor
 import java.net.URLConnection
 import kotlin.io.path.Path
 import kotlin.io.path.extension
+import kotlin.reflect.typeOf
 
 
 public fun <T : Any, R : Any> DataTree<T>.transform(action: Action<T, R>, meta: Meta = Meta.EMPTY): DataTree<R> =
@@ -52,8 +52,8 @@ public class SnarkHtml : WorkspacePlugin() {
         SnarkReader::class.dfType -> mapOf(
             "html".asName() to HtmlReader,
             "markdown".asName() to MarkdownReader,
-            "json".asName() to SnarkReader(JsonMetaFormat, ContentType.Application.Json.toString()),
+            "json".asName() to SnarkReader<Meta>(JsonMetaFormat, ContentType.Application.Json.toString()),
-            "yaml".asName() to SnarkReader(YamlMetaFormat, "text/yaml", "yaml"),
+            "yaml".asName() to SnarkReader<Meta>(YamlMetaFormat, "text/yaml", "yaml"),
         )
 
         else -> super.content(target)
@@ -64,16 +64,33 @@ public class SnarkHtml : WorkspacePlugin() {
         URLConnection.guessContentTypeFromName(filePath) ?: Path(filePath).extension
     }
 
-    public val prepareHeaderAction: ReWrapAction<Any> = ReWrapAction.removeExtensions<Any>("html", "md") { name ->
+    internal val prepareHeaderAction: ReWrapAction<Any> = ReWrapAction(
-        val contentType = getContentType(name, this)
+        type = typeOf<Any>(),
-        set(CONTENT_TYPE_KEY, contentType)
+        newMeta = { name ->
+            val contentType = getContentType(name, this)
+            set(FILE_NAME_KEY, name.last().toStringUnescaped())
+            set(CONTENT_TYPE_KEY, contentType)
+        }
+    ) { name, _, type ->
+        name.replaceLast { token ->
+            val extension = token.body.substringAfterLast('.')
+            if (type != typeOf<Binary>()) {
+                NameToken(token.body.removeSuffix(".$extension"))
+            } else {
+                token
+            }
+        }
     }
 
-    public fun parse(name: Name, markup: String, meta: Meta): PageFragment {
+    public val removeIndexAction: ReWrapAction<Any> = ReWrapAction(typeOf<Any>()) { name, _, _ ->
+        if (name.endsWith("index")) name.cutLast() else name
+    }
+
+    public fun parseMarkup(name: Name, markup: String, meta: Meta): PageFragment {
         val contentType = getContentType(name, meta)
 
         val parser = snark.readers.values.filterIsInstance<SnarkHtmlReader>().filter { parser ->
-            contentType in parser.types
+            contentType in parser.inputContentTypes
         }.maxByOrNull {
             it.priority
         } ?: error("Parser for name $name and meta $meta not found")
@@ -88,10 +105,8 @@ public class SnarkHtml : WorkspacePlugin() {
         }
     }
 
+    public val parseAction: Action<Binary, Any> = ParseAction(this)
 
-    public val removeIndexAction: ReWrapAction<Any> = ReWrapAction.removeIndex<Any>()
-
-    public val parseAction: Action<Binary, PageFragment> = ParseAction(this)
     private val allDataNotNull: DataSelector<Any>
         get() = DataSelector { workspace, _ -> workspace.data.filterByType() }
 
@@ -108,6 +123,8 @@ public class SnarkHtml : WorkspacePlugin() {
     public companion object : PluginFactory<SnarkHtml> {
         override val tag: PluginTag = PluginTag("snark.html")
 
+        public val FILE_NAME_KEY: Name = "contentType".asName()
+
         public val CONTENT_TYPE_KEY: Name = "contentType".asName()
 
         override fun build(context: Context, meta: Meta): SnarkHtml = SnarkHtml()

snark-html/src/jvmMain/kotlin/space/kscience/snark/html/SnarkHtmlReader.kt

@@ -5,12 +5,16 @@ import kotlinx.html.unsafe
 import kotlinx.io.Source
 import kotlinx.io.readString
 import space.kscience.snark.SnarkReader
+import kotlin.reflect.KType
+import kotlin.reflect.typeOf
 
 
-public interface SnarkHtmlReader : SnarkReader<PageFragment>
+public interface SnarkHtmlReader : SnarkReader<PageFragment>{
+    override val outputType: KType get() = typeOf<PageFragment>()
+}
 
 public object HtmlReader : SnarkHtmlReader {
-    override val types: Set<String> = setOf("html")
+    override val inputContentTypes: Set<String> = setOf("html")
 
     override fun readFrom(source: String): PageFragment = PageFragment {
         div {

snark-html/src/jvmMain/kotlin/space/kscience/snark/html/document/DocumentBuilder.kt

@@ -1,9 +1,10 @@
 package space.kscience.snark.html.document
 
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.runBlocking
-import kotlinx.html.body
+import kotlinx.html.*
-import kotlinx.html.head
+import space.kscience.dataforge.context.info
-import kotlinx.html.title
+import space.kscience.dataforge.context.logger
 import space.kscience.dataforge.context.request
 import space.kscience.dataforge.data.*
 import space.kscience.dataforge.meta.Laminate
@@ -11,6 +12,9 @@ import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.get
 import space.kscience.dataforge.meta.string
 import space.kscience.dataforge.names.Name
+import space.kscience.dataforge.names.cutLast
+import space.kscience.dataforge.names.endsWith
+import space.kscience.dataforge.names.parseAsName
 import space.kscience.snark.SnarkBuilder
 import space.kscience.snark.SnarkContext
 import space.kscience.snark.html.*
@@ -26,7 +30,7 @@ public interface DocumentBuilder : SnarkContext {
 
     public val documentMeta: Meta
 
-    public val documentData: DataTree<*>
+    public val data: DataTree<*>
 
     public suspend fun fragment(fragment: Data<*>, overrideMeta: Meta? = null)
 
@@ -43,10 +47,13 @@ public suspend fun DocumentBuilder.fragment(fragmentName: String) {
     fragment(site.siteData[fragmentName] ?: error("Can't find data fragment for $fragmentName in site data."))
 }
 
-private class PageBasedDocumentBuilder(val page: PageContextWithData) : DocumentBuilder {
+private class PageBasedDocumentBuilder(
+    val page: PageContextWithData,
+    private val dataRootName: Name,
+) : DocumentBuilder {
     override val documentName: Name get() = page.pageRoute
     override val documentMeta: Meta get() = page.pageMeta
-    override val documentData: DataTree<*> get() = page.data
+    override val data: DataTree<*> = page.data.branch(dataRootName) ?: DataTree.EMPTY
 
     val fragments = mutableListOf<PageFragment>()
 
@@ -56,24 +63,36 @@ private class PageBasedDocumentBuilder(val page: PageContextWithData) : Document
 
     override suspend fun fragment(fragment: DocumentFragment, overrideMeta: Meta?) {
         when (fragment) {
+
+            is ImageDocumentFragment -> fragment {
+                figure("snark-figure") {
+                    img(classes = "snark-image") {
+                        src = fragment.path
+                        alt = fragment.meta["alt"].string ?: ""
+                    }
+                    fragment.meta["caption"].string?.let { caption ->
+                        figcaption("snark-figure-caption") { +caption }
+                    }
+                }
+            }
+
+            is MarkupDocumentFragment -> {
+                val snarkHtml = page.context.request(SnarkHtml)
+                snarkHtml.parseMarkup(Name.EMPTY, fragment.text, fragment.meta)
+            }
+
+            is DataDocumentFragment -> {
+                val data = data[fragment.name]
+                    ?: error("Can't find data with name ${fragment.name} for $fragment")
+                fragment(data)
+            }
+
             is ListDocumentFragment -> {
                 val meta = Laminate(overrideMeta, fragment.meta)
                 fragment.fragments.forEach { fragment(it, meta) }
             }
 
-            is ImageDocumentFragment -> TODO()
+            is LayoutDocumentFragment -> TODO("Layouts are not implemented")
-            is MarkupDocumentFragment -> {
-                val snarkHtml = page.context.request(SnarkHtml)
-                TODO()
-            }
-
-            is DataDocumentFragment -> {
-                val data = documentData[fragment.dataName]
-                    ?: error("Can't find data with name ${fragment.dataName} for $fragment")
-                fragment(data)
-            }
-
-            is LayoutDocumentFragment -> TODO()
         }
     }
 
@@ -82,7 +101,7 @@ private class PageBasedDocumentBuilder(val page: PageContextWithData) : Document
             typeOf<PageFragment>() -> fragment(fragment.await() as PageFragment)
             typeOf<DocumentFragment>() -> fragment(
                 fragment.await() as DocumentFragment,
-                Laminate(overrideMeta, documentData.meta)
+                Laminate(overrideMeta, data.meta)
             )
 
             typeOf<String>() -> fragment(
@@ -98,11 +117,13 @@ private class PageBasedDocumentBuilder(val page: PageContextWithData) : Document
 public fun SiteContextWithData.document(
     documentName: Name,
     documentMeta: Meta = Meta.EMPTY,
+    headers: MetaDataContent.() -> Unit = {},
     block: suspend DocumentBuilder.() -> Unit,
 ): Unit = page(documentName, documentMeta) {
-    val documentBuilder = runBlocking { PageBasedDocumentBuilder(page).apply { block() } }
+    val documentBuilder = runBlocking { PageBasedDocumentBuilder(page, documentName).apply { block() } }
     head {
         title(documentMeta["title"].string ?: "Snark document")
+        headers()
     }
     body {
         postprocess(FtlDocumentProcessor(this@document.context, documentBuilder)) {
@@ -112,3 +133,57 @@ public fun SiteContextWithData.document(
         }
     }
 }
+
+public fun SiteContextWithData.document(
+    route: Name,
+    dataName: Name,
+    descriptor: DocumentDescriptor,
+    headers: MetaDataContent.() -> Unit = {},
+): Unit = page(route, descriptor.documentMeta ?: Meta.EMPTY) {
+    val documentBuilder = runBlocking {
+        PageBasedDocumentBuilder(page, dataName).apply {
+            descriptor.fragments.forEach {
+                fragment(it)
+            }
+        }
+    }
+    head {
+        title(descriptor.title ?: "Snark document")
+        headers()
+    }
+    body {
+        h1("title") { +(descriptor.title ?: dataName.toString()) }
+        descriptor.authors.forEach {
+            div("author") {
+                div("author-name") { +it.name }
+                it.affiliation?.let { affiliation -> div("author-affiliation") { +affiliation } }
+            }
+        }
+        postprocess(FtlDocumentProcessor(this@document.context, documentBuilder)) {
+            documentBuilder.fragments.forEach {
+                fragment(it)
+            }
+        }
+    }
+}
+
+public fun SiteContextWithData.allDocuments(
+    headers: MetaDataContent.() -> Unit = {},
+) {
+    siteData.forEach { documentData ->
+        if (documentData.type == typeOf<Meta>() && documentData.name.endsWith("document")) {
+            context.launch {
+                val descriptor = DocumentDescriptor.read(documentData.data.await() as Meta)
+                val directory = documentData.name.cutLast()
+                val route = descriptor.route?.parseAsName(false) ?: directory
+                context.logger.info { "Loading document $route" }
+                document(
+                    route = route,
+                    dataName = directory,
+                    descriptor = descriptor,
+                    headers = headers
+                )
+            }
+        }
+    }
+}

snark-html/src/jvmMain/kotlin/space/kscience/snark/html/document/DocumentDescriptor.kt

@@ -0,0 +1,28 @@
+package space.kscience.snark.html.document
+
+import space.kscience.dataforge.meta.*
+import space.kscience.dataforge.misc.DFExperimental
+
+
+public class Author : Scheme() {
+    public var name: String by string { error("Name is required") }
+    public var affiliation: String? by string()
+
+    public companion object : SchemeSpec<Author>(::Author)
+}
+
+public class DocumentDescriptor : Scheme() {
+
+    public var route: String? by string()
+
+    public var title: String? by string()
+
+    public var documentMeta: Meta? by node()
+
+    public var authors: List<Author> by listOfScheme(Author)
+
+    @OptIn(DFExperimental::class)
+    public var fragments: List<DocumentFragment> by meta.listOfSerializable<DocumentFragment>()
+
+    public companion object : SchemeSpec<DocumentDescriptor>(::DocumentDescriptor)
+}

snark-html/src/jvmMain/kotlin/space/kscience/snark/html/document/DocumentFragment.kt

@@ -1,19 +1,46 @@
 package space.kscience.snark.html.document
 
-import kotlinx.io.files.Path
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.names.Name
 
-public sealed interface DocumentFragment{
+@Serializable
+public sealed interface DocumentFragment {
     public val meta: Meta
 }
 
-public class MarkupDocumentFragment(public val text: String, override val meta: Meta) : DocumentFragment
+@Serializable
+@SerialName("markup")
+public class MarkupDocumentFragment(
+    public val text: String,
+    override val meta: Meta = Meta.EMPTY,
+) : DocumentFragment
 
-public class ImageDocumentFragment(public val image: Path, override val meta: Meta) : DocumentFragment
+@Serializable
+@SerialName("image")
+public class ImageDocumentFragment(
+    public val path: String,
+    override val meta: Meta = Meta.EMPTY,
+) : DocumentFragment
 
-public class DataDocumentFragment(public val dataName: Name, override val meta: Meta) : DocumentFragment
+@Serializable
+@SerialName("data")
+public class DataDocumentFragment(
+    public val name: Name,
+    override val meta: Meta = Meta.EMPTY,
+) : DocumentFragment
 
-public class ListDocumentFragment(public val fragments: List<DocumentFragment>, override val meta: Meta) : DocumentFragment
+@Serializable
+@SerialName("list")
+public class ListDocumentFragment(
+    public val fragments: List<DocumentFragment>,
+    override val meta: Meta = Meta.EMPTY,
+) : DocumentFragment
 
-public class LayoutDocumentFragment(public val fragments: Map<String,DocumentFragment>, override val meta: Meta) : DocumentFragment
+@Serializable
+@SerialName("layout")
+public class LayoutDocumentFragment(
+    public val fragments: Map<String, DocumentFragment>,
+    override val meta: Meta = Meta.EMPTY,
+) : DocumentFragment