sample, add exclude from parsing

app-sample/samples.json

@@ -1,4 +1,29 @@
 [
+  {
+    "javaClassName": "io.noties.markwon.app.samples.ExcludeFromParsingSample",
+    "id": "20201111221945",
+    "title": "Exclude part of input from parsing",
+    "description": "Exclude part of input from parsing by splitting input with delimiters",
+    "artifacts": [
+      "CORE"
+    ],
+    "tags": [
+      "parsing"
+    ]
+  },
+  {
+    "javaClassName": "io.noties.markwon.app.samples.parser.CustomHeadingParserSample",
+    "id": "20201111221207",
+    "title": "Custom heading parser",
+    "description": "Custom heading block parser. Actual parser is not implemented",
+    "artifacts": [
+      "CORE"
+    ],
+    "tags": [
+      "heading",
+      "parsing"
+    ]
+  },
   {
     "javaClassName": "io.noties.markwon.app.samples.editor.WYSIWYGEditorSample",
     "id": "20200908133515",

app-sample/src/main/java/io/noties/markwon/app/samples/ExcludeFromParsingSample.kt

@@ -0,0 +1,75 @@
+package io.noties.markwon.app.samples
+
+import android.text.SpannableStringBuilder
+import io.noties.debug.Debug
+import io.noties.markwon.Markwon
+import io.noties.markwon.app.sample.Tags
+import io.noties.markwon.app.sample.ui.MarkwonTextViewSample
+import io.noties.markwon.sample.annotations.MarkwonArtifact
+import io.noties.markwon.sample.annotations.MarkwonSampleInfo
+import java.util.regex.Pattern
+
+@MarkwonSampleInfo(
+  id = "20201111221945",
+  title = "Exclude part of input from parsing",
+  description = "Exclude part of input from parsing by splitting input with delimiters",
+  artifacts = [MarkwonArtifact.CORE],
+  tags = [Tags.parsing]
+)
+class ExcludeFromParsingSample : MarkwonTextViewSample() {
+  override fun render() {
+
+    // cannot have continuous markdown between parts (so a node started in one part and ended in other)
+    //  with this approach
+    // also exclude will start a new block and won't seamlessly continue any existing markdown one (so
+    //  if started inside a blockquote, then blockquote would be closed)
+
+    val md = """
+      # Hello
+      
+      we are **going** to exclude some parts of this input _from_ parsing
+
+      $EXCLUDE_START
+      what is **good** is that we
+      > do not need to care about blocks or inlines
+      * and
+      * everything
+      * else
+      $EXCLUDE_END
+
+      **then** markdown _again_
+      
+      and empty exclude at end: $EXCLUDE_START$EXCLUDE_END
+    """.trimIndent()
+
+    val markwon = Markwon.create(context)
+    val matcher = Pattern.compile(RE, Pattern.MULTILINE).matcher(md)
+
+    val builder by lazy(LazyThreadSafetyMode.NONE) {
+      SpannableStringBuilder()
+    }
+
+    var end: Int = 0
+
+    while (matcher.find()) {
+      val start = matcher.start()
+      Debug.i(end, start, md.substring(end, start))
+      builder.append(markwon.toMarkdown(md.substring(end, start)))
+      builder.append(matcher.group(1))
+      end = matcher.end()
+    }
+
+    if (end != md.length) {
+      builder.append(markwon.toMarkdown(md.substring(end)))
+    }
+
+    markwon.setParsedMarkdown(textView, builder)
+  }
+
+  private companion object {
+    const val EXCLUDE_START = "##IGNORE##"
+    const val EXCLUDE_END = "--IGNORE--"
+
+    const val RE = "${EXCLUDE_START}([\\s\\S]*?)${EXCLUDE_END}"
+  }
+}

app-sample/src/main/java/io/noties/markwon/app/samples/parser/CustomHeadingParserSample.kt

@@ -0,0 +1,47 @@
+package io.noties.markwon.app.samples.parser
+
+import io.noties.markwon.AbstractMarkwonPlugin
+import io.noties.markwon.Markwon
+import io.noties.markwon.app.sample.Tags
+import io.noties.markwon.app.sample.ui.MarkwonTextViewSample
+import io.noties.markwon.core.CorePlugin
+import io.noties.markwon.sample.annotations.MarkwonArtifact
+import io.noties.markwon.sample.annotations.MarkwonSampleInfo
+import org.commonmark.node.Heading
+import org.commonmark.parser.Parser
+import org.commonmark.parser.block.BlockParserFactory
+import org.commonmark.parser.block.BlockStart
+import org.commonmark.parser.block.MatchedBlockParser
+import org.commonmark.parser.block.ParserState
+
+@MarkwonSampleInfo(
+  id = "20201111221207",
+  title = "Custom heading parser",
+  description = "Custom heading block parser. Actual parser is not implemented",
+  artifacts = [MarkwonArtifact.CORE],
+  tags = [Tags.parsing, Tags.heading]
+)
+class CustomHeadingParserSample : MarkwonTextViewSample() {
+  override fun render() {
+    val md = "#Head"
+    val markwon = Markwon.builder(context)
+      .usePlugin(object : AbstractMarkwonPlugin() {
+        override fun configureParser(builder: Parser.Builder) {
+          val enabled = CorePlugin.enabledBlockTypes()
+            .filter { it != Heading::class.java }
+            .toSet()
+          builder.enabledBlockTypes(enabled)
+          builder.customBlockParserFactory(MyHeadingBlockParserFactory)
+        }
+      })
+      .build()
+    markwon.setMarkdown(textView, md)
+  }
+
+  object MyHeadingBlockParserFactory : BlockParserFactory {
+    override fun tryStart(state: ParserState, matchedBlockParser: MatchedBlockParser): BlockStart {
+      // TODO("Not yet implemented")
+      return BlockStart.none()
+    }
+  }
+}