src/main/kotlin/net/pterodactylus/sone/template/LinkedElementRenderFilter.kt

   1 package net.pterodactylus.sone.template
   2
   3 import net.pterodactylus.sone.core.*
   4 import net.pterodactylus.sone.utils.*
   5 import net.pterodactylus.util.template.*
   6 import java.io.*
   7
   8 /**
   9  * Renders all kinds of [LinkedElement]s.
  10  */
  11 class LinkedElementRenderFilter : Filter {
  12
  13         private val templateContextFactory = TemplateContextFactory().apply {
  14                 addFilter("html", HtmlFilter())
  15                 addProvider(ClassPathTemplateProvider(LinkedElementRenderFilter::class.java, "/templates/"))
  16         }
  17
  18         override fun format(templateContext: TemplateContext?, data: Any?, parameters: Map<String, Any?>?) =
  19                         when {
  20                                 data is LinkedElement && data.loading -> renderNotLoadedLinkedElement(data)
  21                                 data is LinkedElement && data.properties["type"] == "image" -> renderLinkedImage(data)
  22                                 data is LinkedElement && data.properties["type"] == "html" -> renderHtmlPage(data)
  23                                 data is LinkedElement && data.properties["type"] == "audio" -> renderAudioPlayer(data)
  24                                 else -> null
  25                         }
  26
  27         private fun renderLinkedImage(linkedElement: LinkedElement) =
  28                         renderTemplate(loadedImageTemplate) { templateContext ->
  29                                 templateContext["link"] = linkedElement.link
  30                         }
  31
  32         private fun renderHtmlPage(linkedElement: LinkedElement) =
  33                         renderTemplate(loadedHtmlPageTemplate) { templateContext ->
  34                                 templateContext["link"] = linkedElement.link
  35                                 templateContext["title"] = linkedElement.properties["title"] ?: "No title"
  36                                 templateContext["description"] = linkedElement.properties["description"] ?: "No description"
  37                         }
  38
  39         private fun renderAudioPlayer(linkedElement: LinkedElement) =
  40                         renderTemplate(loadedAudioTemplate) { templateContext ->
  41                                 templateContext["link"] = linkedElement.link
  42                         }
  43
  44         private fun renderNotLoadedLinkedElement(linkedElement: LinkedElement) =
  45                         renderTemplate(notLoadedImageTemplate) { templateContext ->
  46                                 templateContext["link"] = linkedElement.link
  47                         }
  48
  49         private fun renderTemplate(template: Template, fillTemplateContext: (TemplateContext) -> Unit) =
  50                         StringWriter().use { stringWriter ->
  51                                 stringWriter.also {
  52                                         templateContextFactory.createTemplateContext().also { templateContext ->
  53                                                 fillTemplateContext(templateContext)
  54                                                 template.render(templateContext, stringWriter)
  55                                         }
  56                                 }
  57                         }.toString()
  58
  59 }
  60
  61 private val loadedImageTemplate = """<%include linked/image.html>""".asTemplate()
  62 private val loadedHtmlPageTemplate = """<%include linked/html-page.html>""".asTemplate()
  63 private val loadedAudioTemplate = """<%include linked/audio.html>""".asTemplate()
  64 private val notLoadedImageTemplate = """<%include linked/notLoaded.html>""".asTemplate()