add images to twitter cards

won't really work, since Twitter really likes full URIs ☹

5 files changed, 15 insertions, 0 deletions

diff --git a/src/HW/logscale-calc-tools/document.en.rest.txt b/src/HW/logscale-calc-tools/document.en.rest.txt
index 0c54161..cec42f7 100644
--- a/src/HW/logscale-calc-tools/document.en.rest.txt
+++ b/src/HW/logscale-calc-tools/document.en.rest.txt
@@ -78,6 +78,7 @@ Linear rule:
 
    .. image:: s24d4-1.jpg
       :alt: 4 on C scale matching with 24 on D scale
+      :class: twitter
 
 2) look with what, on the D scale, matches 1 on the C scale
 
diff --git a/src/HW/logscale-calc-tools/document.it.rest.txt b/src/HW/logscale-calc-tools/document.it.rest.txt
index 109ff63..9c43b19 100644
--- a/src/HW/logscale-calc-tools/document.it.rest.txt
+++ b/src/HW/logscale-calc-tools/document.it.rest.txt
@@ -80,6 +80,7 @@ Regolo lineare:
 
    .. image:: s24d4-1.jpg
       :alt: 4 della scala C corrispondente a 24 della scala D
+      :class: twitter
 
 2) guardiamo a cosa, sulla scala D, corrisponde 1 della scala C
 
diff --git a/src/modelli/tachikoma/document.en.rest.txt b/src/modelli/tachikoma/document.en.rest.txt
index fa35d45..89bf4ba 100644
--- a/src/modelli/tachikoma/document.en.rest.txt
+++ b/src/modelli/tachikoma/document.en.rest.txt
@@ -26,6 +26,7 @@ Was it worth it? See for yourself:
 .. image:: front-t.jpg
    :alt: LEGO Tachikoma, from ahead
    :target: front.jpg
+   :class: twitter
 
 .. image:: back-t.jpg
    :alt: LEGO Tachikoma, from behind
diff --git a/src/modelli/tachikoma/document.it.rest.txt b/src/modelli/tachikoma/document.it.rest.txt
index c125b47..29e352e 100644
--- a/src/modelli/tachikoma/document.it.rest.txt
+++ b/src/modelli/tachikoma/document.it.rest.txt
@@ -27,6 +27,7 @@ Ne è valsa la pena? Guardate qua:
 .. image:: front-t.jpg
    :alt: Tachikoma LEGO, da davanti
    :target: front.jpg
+   :class: twitter
 
 .. image:: back-t.jpg
    :alt: Tachikoma LEGO, da dietro
diff --git a/templates/du2html.xsl b/templates/du2html.xsl
index 55fdcd7..aca58ba 100644
--- a/templates/du2html.xsl
+++ b/templates/du2html.xsl
@@ -160,6 +160,16 @@
   <link rel="alternate" type="application/atom+xml" href="{$url}feed.{$language}.xml"/>
  </x:template>
 
+ <x:template match="image[contains(concat(' ',normalize-space(@classes),' '),' twitter ')]" mode="twitter-card">
+  <x:variable name="uri-with-slash" select="wc:dst-uri-for(@uri,/document/@source)" />
+  <!-- dst-uri-for appends a / at the end :( -->
+  <meta name="twitter:image" content="{substring($uri-with-slash,1,string-length($uri-with-slash) - 1)}" />
+  <x:if test="@alt">
+   <meta name="twitter:image:alt" content="{@alt}" />
+  </x:if>
+ </x:template>
+ <x:template match="image" mode="twitter-card" priority="-1" />
+
  <!-- qui ce ne freghiamo del @source, tanto viene usata solo per i
       documenti stand-alone -->
 
@@ -177,6 +187,7 @@
     <meta name="twitter:card" content="summary" />
     <meta name="twitter:site" content="@dakkar" />
     <meta name="twitter:title" content="{normalize-space(title)}" />
+    <x:apply-templates select="//image" mode="twitter-card" />
     <meta name="twitter:description">
      <x:attribute name="content">
       <x:choose>