change filter to filterEach and added filter to apply dynamic filter

Author: ilyapuchka

CHANGELOG.md

@@ -9,7 +9,7 @@
   their stored properties.
 - Allow default string filters to be applied to arrays
 - Similar filters are suggested when unknown filter is used
-- Added `indent`, `split`, `map`, `compact` and `filter` filters
+- Added `indent`, `split`, `map`, `compact`, `filterEach` and `filter` filters
 
 ### Bug Fixes
 

Sources/Extension.swift

@@ -65,6 +65,7 @@ class DefaultExtension: Extension {
     registerFilter("indent", filter: indentFilter)
     registerFilter("map", filter: mapFilter)
     registerFilter("compact", filter: compactFilter)
+    registerFilter("filterEach", filter: filterEachFilter)
     registerFilter("filter", filter: filterFilter)
   }
 }

Sources/Filters.swift

@@ -156,9 +156,9 @@ func compactFilter(value: Any?, arguments: [Any?], context: Context) throws -> A
   })
 }
 
-func filterFilter(value: Any?, arguments: [Any?], context: Context) throws -> Any? {
+func filterEachFilter(value: Any?, arguments: [Any?], context: Context) throws -> Any? {
   guard arguments.count == 1 else {
-    throw TemplateSyntaxError("'filter' filter takes one argument")
+    throw TemplateSyntaxError("'filterEach' filter takes one argument")
   }
 
   let attribute = stringify(arguments[0])
@@ -176,3 +176,18 @@ func filterFilter(value: Any?, arguments: [Any?], context: Context) throws -> An
   return value
 }
 
+func filterFilter(value: Any?, arguments: [Any?], context: Context) throws -> Any? {
+  guard let value = value else { return nil }
+  guard arguments.count == 1 else {
+    throw TemplateSyntaxError("'filter' filter takes one argument")
+  }
+
+  let attribute = stringify(arguments[0])
+  let parser = TokenParser(tokens: [], environment: context.environment)
+
+  let expr = try parser.compileFilter("$0|\(attribute)")
+  return try context.push(dictionary: ["$0": value]) {
+    try expr.resolve(context)
+  }
+}
+

Tests/StencilTests/FilterSpec.swift

@@ -316,24 +316,40 @@ func testFilter() {
 
   }
 
-  describe("filter filter") {
+  describe("filterEach filter") {
 
     $0.it("can filter using filter") {
       let env = environmentWithFilter("isPositive") { (value) -> Any? in
         if let number = toNumber(value: value as Any) { return number > 0 }
         else { return nil }
       }
 
-      let template = Template(templateString: "{{ array|filter:'$0|isPositive' }}")
+      let template = Template(templateString: "{{ array|filterEach:'$0|isPositive' }}")
       let result = try template.render(Context(dictionary: ["array": [1, -1, 2, -2, 3, -3]], environment: env))
       try expect(result) == "[1, 2, 3]"
     }
 
     $0.it("can filter using boolean expression") {
-      let template = Template(templateString: "{{ array|filter:'$0 > 0' }}")
+      let template = Template(templateString: "{{ array|filterEach:'$0 > 0' }}")
       let result = try template.render(Context(dictionary: ["array": [1, -1, 2, -2, 3, -3]]))
       try expect(result) == "[1, 2, 3]"
     }
 
   }
+
+  describe("filter filter") {
+
+    $0.it("can apply dynamic filter") {
+        let template = Template(templateString: "{{ name|filter:somefilter }}")
+        let result = try template.render(Context(dictionary: ["name": "Jhon", "somefilter": "uppercase"]))
+        try expect(result) == "JHON"
+    }
+
+    $0.it("can apply dynamic filter on array") {
+      let template = Template(templateString: "{{ values|filter:joinfilter }}")
+      let result = try template.render(Context(dictionary: ["values": [1, 2, 3], "joinfilter": "join:\", \""]))
+      try expect(result) == "1, 2, 3"
+    }
+
+  }
 }