Autobinding handlers syntax (#109)

src/options.js

@@ -116,5 +116,10 @@ $ rt <filename> [<filename> ...] [<args>]`,
         type: 'String',
         default: reactNativeSupport.default,
         description: `'React native version to generate code for (${Object.keys(reactNativeSupport).join(', ')})'`
+    }, {
+        option: 'autobind',
+        type: 'Boolean',
+        default: 'false',
+        description: 'Automatically bind event handlers to components'
     }]
 });

src/reactTemplates.js

@@ -199,18 +199,28 @@ function generateProps(node, context) {
 }
 
 function handleEventHandler(val, context, node, key) {
-    const funcParts = val.split('=>');
-    if (funcParts.length !== 2) {
-        throw RTCodeError.build(context, node, `when using 'on' events, use lambda '(p1,p2)=>body' notation or use {} to return a callback function. error: [${key}='${val}']`);
-    }
-    const evtParams = funcParts[0].replace('(', '').replace(')', '').trim();
-    const funcBody = funcParts[1].trim();
-    let params = context.boundParams;
-    if (evtParams.trim() !== '') {
-        params = params.concat([evtParams.trim()]);
+    let handlerString;
+    if (_.startsWith(val, 'this.')) {
+        if (context.options.autobind) {
+            handlerString = `${val}.bind(this)`;
+        } else {
+            throw RTCodeError.build(context, node, "'this.handler' syntax allowed only when the --autobind is on, use {} to return a callback function.");
+        }
+    } else {
+        const funcParts = val.split('=>');
+        if (funcParts.length !== 2) {
+            throw RTCodeError.build(context, node, `when using 'on' events, use lambda '(p1,p2)=>body' notation or 'this.handler'; otherwise use {} to return a callback function. error: [${key}='${val}']`);
+        }
+        const evtParams = funcParts[0].replace('(', '').replace(')', '').trim();
+        const funcBody = funcParts[1].trim();
+        let params = context.boundParams;
+        if (evtParams.trim() !== '') {
+            params = params.concat([evtParams.trim()]);
+        }
+        const generatedFuncName = generateInjectedFunc(context, key, funcBody, params);
+        handlerString = genBind(generatedFuncName, context.boundParams);
     }
-    const generatedFuncName = generateInjectedFunc(context, key, funcBody, params);
-    return genBind(generatedFuncName, context.boundParams);
+    return handlerString;
 }
 
 function genBind(func, args) {

test/data/autobind.rt

@@ -0,0 +1,2 @@
+<div onKeyDown="this.handleKeyDown"></div>
+

test/data/autobind.rt.js

@@ -0,0 +1,10 @@
+define([
+    'react',
+    'lodash'
+], function (React, _) {
+    'use strict';
+    return function () {
+        return React.createElement('div', { 'onKeyDown': this.handleKeyDown.bind(this) });
+    };
+});
+

test/data/invalid/invalid-autobind.rt

@@ -0,0 +1,4 @@
+<div onKeyDown="this.handleKeyDown">
+   This should trigger an error because evaluated with no autobinding (--autobind=false)
+</div>
+

test/src/rt.invalid.spec.js

@@ -19,7 +19,8 @@ module.exports = {
             {file: 'invalid-scope.rt', issue: new RTCodeError("invalid scope part 'a in a in a'", 0, 35, 1, 1)},
             {file: 'invalid-html.rt', issue: new RTCodeError('Document should have a root element', -1, -1, -1, -1)},
             {file: 'invalid-exp.rt', issue: new RTCodeError("Failed to parse text '\n    {z\n'", 5, 13, 1, 6)},
-            {file: 'invalid-lambda.rt', issue: new RTCodeError("when using 'on' events, use lambda '(p1,p2)=>body' notation or use {} to return a callback function. error: [onClick='']", 0, 23, 1, 1)},
+            {file: 'invalid-lambda.rt', issue: new RTCodeError("when using 'on' events, use lambda '(p1,p2)=>body' notation or 'this.handler'; otherwise use {} to return a callback function. error: [onClick='']", 0, 23, 1, 1)},
+            {file: 'invalid-autobind.rt', issue: new RTCodeError("'this.handler' syntax allowed only when the --autobind is on, use {} to return a callback function.", 0, 132, 1, 1)},
             {file: 'invalid-js.rt', issue: new RTCodeError('Unexpected token ILLEGAL', 0, 32, 1, 1)},
             {file: 'invalid-single-root.rt', issue: new RTCodeError('Document should have no more than a single root element', 12, 23, 2, 1)},
             {file: 'invalid-repeat.rt', issue: new RTCodeError('rt-repeat invalid \'in\' expression \'a in b in c\'', 0, 35, 1, 1)},

test/src/rt.valid.spec.js

@@ -33,6 +33,14 @@ module.exports = {
             testFiles(t, files);
         });
 
+        test('autobinding conversion test', t => {
+            const options = {
+                autobind: true
+            };
+            const files = ['autobind.rt'];
+            testFiles(t, files, options);
+        });
+
         test('prop template conversion test', t => {
             const options = {
                 propTemplates: {