Conditional text (#1053)

* Adds conditional-text shortcode

* Documents conditional-text shortcode

* Typo correction

Co-authored-by: LisaFC <lcarey@google.com>

layouts/shortcodes/conditional-text.html

@@ -0,0 +1,36 @@
+<!-- Get the current buildcondition from the config and lowercase it -->
+{{ $condition := lower $.Site.Params.buildCondition }}
+
+{{ if ne $condition "" }}
+
+    <!-- Get the parameters from the shortcode invocation and lowercase them.
+    TODO: to enable multiple conditions, we could accept comma-separated lists and split them -->
+    {{ $include_if := lower (.Get "include-if") }}
+    {{ $exclude_if := lower (.Get "exclude-if") }}
+
+    {{ if and (in $include_if $condition) (in $exclude_if $condition) }}
+        <!-- condition appears in both parameters -->
+        {{- errorf "Build condition %q appears in both include-if and exclude-if parameters of conditional-txt shortcode on page %s" $condition .Position -}}
+    {{ end }}
+
+    {{ if isset $.Params "include-if" }}
+        <!-- WARNING substring matches are matches as well! That means, if include-if="foobar", and buildcondition is "foo", you have a match!-->
+        {{ if in $include_if $condition }}
+<!-- Do not indent the next Inner line, because the inner becomes a blockquote if the conditional-text is nested in another shortcode  -->
+{{ .Inner }}
+        {{ else }}
+        {{ end }}
+    {{ else }}
+
+        {{ if isset $.Params "exclude-if" }}
+            <!-- WARNING substring matches are matches as well! That means, if exclude-if="foobar", and buildcondition is "foo", you have a match!-->
+            {{ if in $exclude_if $condition }}
+            {{ else }}
+<!-- Do not indent the next Inner line, because the inner becomes a blockquote if the conditional-text is nested in another shortcode  -->
+{{ .Inner }}
+            {{ end }}
+        {{ end }}
+
+    {{ end }}
+
+{{ end }}

userguide/content/en/docs/Adding content/Shortcodes/index.md

@@ -662,3 +662,17 @@ starting with `/`. The root directory is the `/content` folder.
 | code | false | Boolean value. If `true` the contents is treated as code|
 | lang | plain text | Programming language |
 
+## Conditional text
+
+The `conditional-text` shortcode allows you to show or hide parts of your content depending on the value of the `buildCondition` parameter set in your configuration file. This can be useful if you are generating different builds from the same source, for example, using a different product name. This shortcode helps you handle the minor differences between these builds.
+
+```text
+{{%/* conditional-text include-if="foo" */%}}
+This text appears in the output only if `buildCondition = "foo" is set in your config file`.
+{{%/* /conditional-text */%}}
+{{%/* conditional-text exclude-if="bar" */%}}
+This text does not appear in the output if `buildCondition = "bar" is set in your config file`.
+{{%/* /conditional-text */%}}
+```
+
+If you are using this shortcode, note that when evaluating the conditions, substring matches are matches as well. That means, if you set `include-if="foobar"`, and `buildcondition = "foo"`, you have a match!