adds the #equal helper (fixes #7)

README.md

@@ -22,6 +22,7 @@ The full API documentation is available here: <http://godoc.org/github.com/aymer
     - [The `with` block helper](#the-with-block-helper)
     - [The `lookup` helper](#the-lookup-helper)
     - [The `log` helper](#the-log-helper)
+    - [The `equal` helper](#the-equal-helper)
   - [Block Helpers](#block-helpers)
     - [Block Evaluation](#block-evaluation)
     - [Conditional](#conditional)
@@ -642,6 +643,41 @@ The `log` helper allows for logging while rendering a template.
 Note that the handlebars.js `@level` variable is not supported.
 
 
+#### The `equal` helper
+
+The `equal` helper renders a block if the string version of both arguments are equals.
+
+For example that template:
+
+```html
+{{#equal foo "bar"}}foo is bar{{/equal}}
+{{#equal foo baz}}foo is the same as baz{{/equal}}
+{{#equal nb 0}}nothing{{/equal}}
+{{#equal nb 1}}there is one{{/equal}}
+{{#equal nb "1"}}everything is stringified before comparison{{/equal}}
+```
+
+With that context:
+
+```go
+ctx := map[string]interface{}{
+    "foo": "bar",
+    "baz": "bar",
+    "nb":  1,
+}
+```
+
+Outputs:
+
+```html
+foo is bar
+foo is the same as baz
+
+there is one
+everything is stringified before comparison
+```
+
+
 ### Block Helpers
 
 Block helpers make it possible to define custom iterators and other functionality that can invoke the passed block with a new context.

helper.go

@@ -31,6 +31,7 @@ func init() {
 	RegisterHelper("each", eachHelper)
 	RegisterHelper("log", logHelper)
 	RegisterHelper("lookup", lookupHelper)
+	RegisterHelper("equal", equalHelper)
 }
 
 // RegisterHelper registers a global helper. That helper will be available to all templates.
@@ -369,3 +370,13 @@ func logHelper(message string) interface{} {
 func lookupHelper(obj interface{}, field string, options *Options) interface{} {
 	return Str(options.Eval(obj, field))
 }
+
+// #equal helper
+// Ref: https://github.com/aymerick/raymond/issues/7
+func equalHelper(a interface{}, b interface{}, options *Options) interface{} {
+	if Str(a) == Str(b) {
+		return options.Fn()
+	}
+
+	return ""
+}

helper_test.go

@@ -152,6 +152,74 @@ var helperTests = []Test{
 		nil, nil, nil,
 		`YES MAN`,
 	},
+	{
+		"#equal helper with same string var",
+		`{{#equal foo "bar"}}YES MAN{{/equal}}`,
+		map[string]interface{}{"foo": "bar"},
+		nil, nil, nil,
+		`YES MAN`,
+	},
+	{
+		"#equal helper with different string var",
+		`{{#equal foo "baz"}}YES MAN{{/equal}}`,
+		map[string]interface{}{"foo": "bar"},
+		nil, nil, nil,
+		``,
+	},
+	{
+		"#equal helper with same string vars",
+		`{{#equal foo bar}}YES MAN{{/equal}}`,
+		map[string]interface{}{"foo": "baz", "bar": "baz"},
+		nil, nil, nil,
+		`YES MAN`,
+	},
+	{
+		"#equal helper with different string vars",
+		`{{#equal foo bar}}YES MAN{{/equal}}`,
+		map[string]interface{}{"foo": "baz", "bar": "tag"},
+		nil, nil, nil,
+		``,
+	},
+	{
+		"#equal helper with same integer var",
+		`{{#equal foo 1}}YES MAN{{/equal}}`,
+		map[string]interface{}{"foo": 1},
+		nil, nil, nil,
+		`YES MAN`,
+	},
+	{
+		"#equal helper with different integer var",
+		`{{#equal foo 0}}YES MAN{{/equal}}`,
+		map[string]interface{}{"foo": 1},
+		nil, nil, nil,
+		``,
+	},
+	{
+		"#equal helper inside HTML tag",
+		`<option value="test" {{#equal value "test"}}selected{{/equal}}>Test</option>`,
+		map[string]interface{}{"value": "test"},
+		nil, nil, nil,
+		`<option value="test" selected>Test</option>`,
+	},
+	{
+		"#equal full example",
+		`{{#equal foo "bar"}}foo is bar{{/equal}}
+{{#equal foo baz}}foo is the same as baz{{/equal}}
+{{#equal nb 0}}nothing{{/equal}}
+{{#equal nb 1}}there is one{{/equal}}
+{{#equal nb "1"}}everything is stringified before comparison{{/equal}}`,
+		map[string]interface{}{
+			"foo": "bar",
+			"baz": "bar",
+			"nb":  1,
+		},
+		nil, nil, nil,
+		`foo is bar
+foo is the same as baz
+
+there is one
+everything is stringified before comparison`,
+	},
 }
 
 //