Add support for variables in text style

Author: YomesInc

CloudinaryDotNet.Tests/Asset/UrlBuilderTest.cs

@@ -576,5 +576,25 @@ public void TestApiUrlWithPrivateCdn()
 
             StringAssert.StartsWith("https://api.cloudinary.com", urlZipImage);
         }
+
+        [Test]
+        public void TestTextLayerStyleIdentifierVariables()
+        {
+            string buildUrl(Func<TextLayer, TextLayer> setTextStyleAction) =>
+                m_api.UrlImgUp.Transform(
+                    new Transformation()
+                        .Variable("$style", "!Arial_12!")
+                        .Chain()
+                        .Overlay(
+                            setTextStyleAction(new TextLayer().Text("hello-world"))
+                        )
+                ).BuildUrl("sample");
+
+            var expected =
+                "http://res.cloudinary.com/testcloud/image/upload/$style_!Arial_12!/l_text:$style:hello-world/sample";
+
+            Assert.AreEqual(expected, buildUrl(l => l.TextStyle("$style")));
+            Assert.AreEqual(expected, buildUrl(l => l.TextStyle(new Expression("$style"))));
+        }
     }
 }

CloudinaryDotNet/Transforms/TextLayer.cs

@@ -92,6 +92,11 @@ public class TextLayer : BaseLayer<TextLayer>
         /// </summary>
         protected string m_text;
 
+        /// <summary>
+        /// The text style to generate an image for.
+        /// </summary>
+        protected object m_textStyle;
+
         /// <summary>
         /// Required name of the font family. e.g. "arial".
         /// </summary>
@@ -209,6 +214,30 @@ public TextLayer Text(string text)
             return this;
         }
 
+        /// <summary>
+        /// Sets a text style identifier.
+        /// Note: If this is used, all other style attributes are ignored in favor of this identifier.
+        /// </summary>
+        /// <param name="textStyleIdentifier">A variable string or an explicit style (e.g. "Arial_17_bold_antialias_best").</param>
+        /// <returns>The layer with text style applied.</returns>
+        public TextLayer TextStyle(string textStyleIdentifier)
+        {
+            this.m_textStyle = textStyleIdentifier;
+            return this;
+        }
+
+        /// <summary>
+        /// Sets a text style identifier.
+        /// Note: If this is used, all other style attributes are ignored in favor of this identifier.
+        /// </summary>
+        /// <param name="textStyleIdentifier">An expression instance referencing the style..</param>
+        /// <returns>The layer with text style applied.</returns>
+        public TextLayer TextStyle(Expression textStyleIdentifier)
+        {
+            this.m_textStyle = textStyleIdentifier;
+            return this;
+        }
+
         /// <summary>
         /// Type of font antialiasing to use.
         /// </summary>
@@ -396,6 +425,12 @@ private string OverlayTextEncode(string text)
 
         private string TextStyleIdentifier()
         {
+            var ts = m_textStyle?.ToString();
+            if (!string.IsNullOrEmpty(ts))
+            {
+                return ts;
+            }
+
             List<string> components = new List<string>();
 
             if (!string.IsNullOrEmpty(m_fontWeight) && !m_fontWeight.Equals("normal", StringComparison.Ordinal))