From c791158dd5ea8ea03930f9881a86c71cb1770836 Mon Sep 17 00:00:00 2001
From: Kolja Markwardt <kolja.markwardt@web.de>
Date: Mon, 11 Oct 2021 17:11:06 +0200
Subject: [PATCH] feat: add string template filters "default" and "ternary"
 (#3677) (#5878)

---
 .../src/__tests__/stringTemplate.spec.js      | 22 +++++++++++++++++++
 .../src/stringTemplate.ts                     |  8 +++++++
 website/content/docs/beta-features.md         |  2 +-
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/packages/netlify-cms-lib-widgets/src/__tests__/stringTemplate.spec.js b/packages/netlify-cms-lib-widgets/src/__tests__/stringTemplate.spec.js
index 5d38e242..3a62a341 100644
--- a/packages/netlify-cms-lib-widgets/src/__tests__/stringTemplate.spec.js
+++ b/packages/netlify-cms-lib-widgets/src/__tests__/stringTemplate.spec.js
@@ -130,6 +130,28 @@ describe('stringTemplate', () => {
         ),
       ).toBe('BACKENDSLUG-title-01-02-2020');
     });
+
+    it('return apply filter for default value', () => {
+      expect(
+        compileStringTemplate(
+          "{{slug | upper}}-{{title | default('none')}}-{{subtitle | default('none')}}",
+          date,
+          'backendSlug',
+          fromJS({ slug: 'entrySlug', title: 'title', subtitle: null, published: date, date }),
+        ),
+      ).toBe('BACKENDSLUG-title-none');
+    });
+
+    it('return apply filter for ternary', () => {
+      expect(
+        compileStringTemplate(
+          "{{slug | upper}}-{{starred | ternary('star️','nostar')}}-{{done | ternary('done', 'open️')}}",
+          date,
+          'backendSlug',
+          fromJS({ slug: 'entrySlug', starred: true, done: false }),
+        ),
+      ).toBe('BACKENDSLUG-star️-open️');
+    });
   });
 
   describe('expandPath', () => {
diff --git a/packages/netlify-cms-lib-widgets/src/stringTemplate.ts b/packages/netlify-cms-lib-widgets/src/stringTemplate.ts
index 9671a233..7773316d 100644
--- a/packages/netlify-cms-lib-widgets/src/stringTemplate.ts
+++ b/packages/netlify-cms-lib-widgets/src/stringTemplate.ts
@@ -13,6 +13,14 @@ const filters = [
     pattern: /^date\('(.+)'\)$/,
     transform: (str: string, match: RegExpMatchArray) => moment(str).format(match[1]),
   },
+  {
+    pattern: /^default\('(.+)'\)$/,
+    transform: (str: string, match: RegExpMatchArray) => (str ? str : match[1]),
+  },
+  {
+    pattern: /^ternary\('(.*)',\s*'(.*)'\)$/,
+    transform: (str: string, match: RegExpMatchArray) => (str ? match[1] : match[2]),
+  },
 ];
 
 const FIELD_PREFIX = 'fields.';
diff --git a/website/content/docs/beta-features.md b/website/content/docs/beta-features.md
index 80005d0d..41fa722a 100644
--- a/website/content/docs/beta-features.md
+++ b/website/content/docs/beta-features.md
@@ -545,7 +545,7 @@ collections:
 ```
 
 The above config will transform the title field to uppercase and format the date field using `YYYY-MM-DD` format.
-Available transformations are `upper`, `lower` and `date('<format>')`
+Available transformations are `upper`, `lower`, `date('<format>'), default('defaultValue') and ternary('valueForTrue','valueForFalse')`
 
 ## Registering to CMS Events