Introduce concept of scopes, with the engine simply being one. #12
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This opens possibilities to render contexts in different scopes, e.g. a HTTP request scope, which then pass language and internationalization preferences See xp-forge/handlebars-templates#1
...which is essentially the same but offers greater flexibility
...to clarify purpose
Range of BC breaksDiff against handlebars library to restore compatibility:
Detailsdiff --git a/src/main/php/com/handlebarsjs/Decoration.class.php b/src/main/php/com/handlebarsjs/Decoration.class.php
index 2582c01..4cfce99 100755
--- a/src/main/php/com/handlebarsjs/Decoration.class.php
+++ b/src/main/php/com/handlebarsjs/Decoration.class.php
@@ -37,11 +37,11 @@ class Decoration {
* @return void
*/
public function enter($context) {
- if (isset($context->engine->helpers[$this->kind])) {
- $f= $context->engine->helpers[$this->kind];
+ if (isset($context->scope->helpers[$this->kind])) {
+ $f= $context->scope->helpers[$this->kind];
$f($this->fn, $context, $this->options);
} else {
- throw new MethodNotImplementedException('No such decorator '.$this->kind);
+ throw new MethodNotImplementedException('No such decorator', $this->kind);
}
}
}
\ No newline at end of file
diff --git a/src/main/php/com/handlebarsjs/HandlebarsEngine.class.php b/src/main/php/com/handlebarsjs/HandlebarsEngine.class.php
index aa3922c..d762fbc 100755
--- a/src/main/php/com/handlebarsjs/HandlebarsEngine.class.php
+++ b/src/main/php/com/handlebarsjs/HandlebarsEngine.class.php
@@ -41,7 +41,7 @@ class HandlebarsEngine {
return $options[0][$options[1]] ?? null;
},
'*inline' => function($node, $context, $options) {
- $context->engine->templates->declare($options[0]($node, $context, []), $node);
+ $context->scope->templates->declare($options[0]($node, $context, []), $node);
}
];
}
@@ -172,7 +172,7 @@ class HandlebarsEngine {
*/
public function evaluate(Template $template, $arg) {
$c= $arg instanceof Context ? $arg : new DataContext($arg);
- return $template->evaluate($c->withEngine($this));
+ return $template->evaluate($c->inScope($this));
}
/**
@@ -185,7 +185,7 @@ class HandlebarsEngine {
*/
public function write(Template $template, $arg, $out) {
$c= $arg instanceof Context ? $arg : new DataContext($arg);
- $template->write($c->withEngine($this), $out);
+ $template->write($c->inScope($this), $out);
}
/**
diff --git a/src/main/php/com/handlebarsjs/HashContext.class.php b/src/main/php/com/handlebarsjs/HashContext.class.php
index b75b6d3..82d1061 100755
--- a/src/main/php/com/handlebarsjs/HashContext.class.php
+++ b/src/main/php/com/handlebarsjs/HashContext.class.php
@@ -30,10 +30,11 @@ class HashContext extends Context {
* Returns a context inherited from this context
*
* @param var $result
+ * @param parent $parent
* @return self
*/
- public function asContext($result) {
- return new DataContext($result, $this);
+ public function asContext($result, $parent= null) {
+ return new DataContext($result, $parent ?? $this);
}
/**
diff --git a/src/main/php/com/handlebarsjs/ListContext.class.php b/src/main/php/com/handlebarsjs/ListContext.class.php
index 5de5269..c9e9bf6 100755
--- a/src/main/php/com/handlebarsjs/ListContext.class.php
+++ b/src/main/php/com/handlebarsjs/ListContext.class.php
@@ -30,10 +30,11 @@ class ListContext extends Context {
* Returns a context inherited from this context
*
* @param var $result
+ * @param parent $parent
* @return self
*/
- public function asContext($result) {
- return new DataContext($result, $this);
+ public function asContext($result, $parent= null) {
+ return new DataContext($result, $parent ?? $this);
}
/**
diff --git a/src/main/php/com/handlebarsjs/PartialBlockHelper.class.php b/src/main/php/com/handlebarsjs/PartialBlockHelper.class.php
index 2061f0d..0924bc3 100755
--- a/src/main/php/com/handlebarsjs/PartialBlockHelper.class.php
+++ b/src/main/php/com/handlebarsjs/PartialBlockHelper.class.php
@@ -31,27 +31,27 @@ class PartialBlockHelper extends BlockNode {
* @param io.streams.OutputStream $out
*/
public function write($context, $out) {
- $templates= $context->engine->templates();
+ $templates= $context->scope->templates();
// {{#> partial context}} vs {{> partial key="Value"}}
if (isset($this->options[0])) {
- $context= $context->newInstance($this->options[0]($this, $context, []));
+ $context= $context->asContext($this->options[0]($this, $context, []));
} else if ($this->options) {
$pass= [];
foreach ($context->asTraversable($this->options) as $key => $value) {
$pass[$key]= $value($this, $context, []);
}
- $context= $context->newInstance($pass);
+ $context= $context->asContext($pass);
}
$source= $templates->source($this->name);
if ($source->exists()) {
$this->fn->enter($context);
- $template= $context->engine->load($this->name, $this->start, $this->end, '');
+ $template= $context->scope->load($this->name, $this->start, $this->end, '');
$previous= $templates->register('@partial-block', $this->fn->block());
try {
- $context->engine->write($template, $context, $out);
+ $context->scope->write($template, $context, $out);
} finally {
$templates->register('@partial-block', $previous);
}
diff --git a/src/main/php/com/handlebarsjs/PartialNode.class.php b/src/main/php/com/handlebarsjs/PartialNode.class.php
index 7762aef..3582b07 100755
--- a/src/main/php/com/handlebarsjs/PartialNode.class.php
+++ b/src/main/php/com/handlebarsjs/PartialNode.class.php
@@ -92,16 +92,16 @@ class PartialNode extends Node {
// {{> partial context}} vs {{> partial key="Value"}}
if (isset($this->options[0])) {
- $context= $context->newInstance($this->options[0]($this, $context, []));
+ $context= $context->asContext($this->options[0]($this, $context, []));
} else if ($this->options) {
$pass= [];
foreach ($context->asTraversable($this->options) as $key => $value) {
$pass[$key]= $value($this, $context, []);
}
- $context= $context->newInstance($pass);
+ $context= $context->asContext($pass);
}
- $engine= $context->engine;
+ $engine= $context->scope;
$template= $engine->load($this->template->__invoke($this, $context, []), '{{', '}}', $this->indent);
$engine->write($template, $context, $out);
}
diff --git a/src/main/php/com/handlebarsjs/Templates.class.php b/src/main/php/com/handlebarsjs/Templates.class.php
index ecea071..b171738 100755
--- a/src/main/php/com/handlebarsjs/Templates.class.php
+++ b/src/main/php/com/handlebarsjs/Templates.class.php
@@ -1,9 +1,8 @@
<?php namespace com\handlebarsjs;
-use com\github\mustache\templates\{Compiled, NotFound, Source, Tokens};
-use com\github\mustache\{Node, Template, TemplateListing};
+use com\github\mustache\templates\{Compiled, NotFound, Source, Listing, InString};
+use com\github\mustache\{Node, Template};
use lang\{ClassLoader, IllegalArgumentException};
-use text\StringTokenizer;
/**
* Template loading implementation
@@ -18,7 +17,7 @@ class Templates {
/** @return lang.XPClass */
private function composite() {
if (null === self::$composite) {
- self::$composite= ClassLoader::defineClass('CompositeListing', TemplateListing::class, [], [
+ self::$composite= ClassLoader::defineClass('CompositeListing', Listing::class, [], [
'templates' => null,
'delegate' => null,
'__construct' => function($templates, $delegate) {
@@ -78,7 +77,7 @@ class Templates {
} else if ($content instanceof Node) {
$this->templates[$name]= new Compiled(new Template($name, $content));
} else {
- $this->templates[$name]= new Tokens($name, new StringTokenizer($content));
+ $this->templates[$name]= new InString($name, $content);
}
return $previous;
@@ -92,7 +91,7 @@ class Templates {
* @return com.github.mustache.templates.Source
*/
public function tokens($content, $name= '(string)') {
- return new Tokens($name, new StringTokenizer((string)$content));
+ return new InString($name, (string)$content);
}
/**
@@ -111,12 +110,12 @@ class Templates {
}
}
- /** @return com.github.mustache.TemplateListing */
+ /** @return com.github.mustache.templates.Listing */
public function listing() {
if ($this->delegate) {
return $this->composite()->newInstance($this->templates, $this->delegate->listing());
} else {
- return new TemplateListing('', function($package) { return array_keys($this->templates); });
+ return new Listing('', function($package) { return array_keys($this->templates); });
}
}
}
\ No newline at end of file
diff --git a/src/test/php/com/handlebarsjs/unittest/HelperTest.class.php b/src/test/php/com/handlebarsjs/unittest/HelperTest.class.php
index 5cab52a..94da851 100755
--- a/src/test/php/com/handlebarsjs/unittest/HelperTest.class.php
+++ b/src/test/php/com/handlebarsjs/unittest/HelperTest.class.php
@@ -1,19 +1,19 @@
<?php namespace com\handlebarsjs\unittest;
use com\github\mustache\InMemory;
-use com\github\mustache\templates\Templates;
+use com\github\mustache\templates\Sources;
use com\handlebarsjs\HandlebarsEngine;
/** Base class for all helper tests */
abstract class HelperTest {
/** Returns in-memory templates initialized from a given map */
- protected function templates(array $templates= []): Templates {
+ protected function templates(array $templates= []): Sources {
return new InMemory($templates);
}
/** Returns handlebars engine with specified templates */
- protected function engine(Templates $templates= null): HandlebarsEngine {
+ protected function engine(Sources $templates= null): HandlebarsEngine {
return (new HandlebarsEngine())->withTemplates($templates ?? $this->templates());
}
|
...and reduce reliance on reflection at the same time, see xp-framework/rfc#338
thekid
added a commit
to xp-forge/handlebars
that referenced
this pull request
Feb 27, 2021
|
With all this, this is how Mustache and Handlebars engines compare: // MustacheEngine class extends Scope
public function evaluate(Template $template, $context) {
$c= $context instanceof Context ? $context : new DataContext($context);
return $template->evaluate($c->inScope($this));
}
// HandlebarsEngine class comes without parent, Transformation extends Scope
public function evaluate(Template $template, $context) {
$c= $context instanceof Context ? $context : new DataContext($context);
return $template->evaluate($c->inScope(new Transformation($this->templates, $this->helpers)));
}While in Mustache, the engine itself is the scope, in handlebars we create a new Transformation scope for each template evaluation. This is so we can support However, we now have to know these internal implementation details - that templates need to be passed a Transformation instance when using the Handlebars engine and on the other hand when using Mustache, we can simply pass the engine - if we use its $context= ['user' => '@test'];
$template= $engine->compile('Hello {{user}}');
// This is where it gets messy:
$c= $context instanceof Context ? $context : new DataContext($context);
$template->evaluate($c->inScope($engine));
$template->evaluate($c->inScope(new Transformation($engine->templates(), $engine->helpers())));If we add a method to create a context, we could encapsulate these details: // On the engine:
public function context($context) {
$c= $context instanceof Context ? $context : new DataContext($context);
return $c->inScope($this); // or inScope(new Transformation(...))
}
// The above code then would read:
$template= $engine->compile('Hello {{user}}');
$template->evaluate($engine->context(['user' => '@test']));Still, it's not easily possible to integrate the concept of something like a |
If we wrap scopes around their parents, it might work: // On the scope:
public function wrap(self $parent) {
$this->templates= $parent->templates;
$this->helpers= $parent->helpers;
return $this;
}
// On the engine:
public function context($context, Scope $scope= null) {
$c= $context instanceof Context ? $context : new DataContext($context);
return $c->inScope($scope ? $scope->wrap($this) : $this); // same with s/$this/new Transformation(...)/g
}
// The above code then would read:
$template= $engine->compile('Hello {{user}}');
$template->evaluate($engine->context(['user' => '@test'], new RequestScope($request)));...but only for the top-most scope, as |
Another idea would be to rename scope helpers to variables (or globals) and then have the following possibility: yield 't' => function($in, $context, $options) {
$lang= $context->scope->globals['request']->values('user')['language'];
// ...
}...or even registering the language beforehand: // In scope:
public function including($globals) {
$this->globals+= $globals;
return $this;
}
// Call
$template= $engine->compile('Hello {{user}}');
$template->evaluate($engine->context(['user' => '@test'])->including(['lang' => $request->values('user')['language']));
// Helper
yield 't' => function($in, $context, $options) {
$lang= $context->scope->globals['lang'];
// ...
}Alternatively, we could pass an object to globals: class LocalizationOf {
public $language;
public function __construct($request) {
$this->language= $this->negotiate($request->header('Accept-Language'));
}
}
// In scope:
public function including($globals) {
$this->globals= $this->helpers['globals']= $globals;
return $this;
}
// Call
$template= $engine->compile('Hello {{user}}');
$template->evaluate($engine->context(['user' => '@test'])->including(new LocalizationOf($request));
// Helper
yield 't' => function($in, $context, $options) {
$lang= $context->scope->globals->language;
// ...
} |
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This opens possibilities to render contexts in different scopes, e.g. a HTTP request scope, which then pass language and internationalization preferences
Refactoring
com.github.mustache.ScopeclassContext::inScope()to replace::withEngine()Templating
The templating mechanism consist of consists of template sources, which are responsible for loading the templates' code from a given source (e.g. the filesystem) and the template parser, which parses these tokens into a parse tree.
Template sources are represented by the Sources class. The following templates sources exist:
Their
source()methods return Source instances:...which are then used to return the tokenized templates.
See xp-forge/handlebars-templates#1