If `global` is used and handlebars is compiled for browser
usage without a Node.js `global` polyfill, handlebars
fails with a `global is undefined` error.
Fixes#1593
Extracts the parser to `@handlebars/parser`, where it can be shared
between different implementations. This means that e.g. Glimmer/Ember
will be able to iterate on new features without forcing Handlebars to
adopt them immediately, and vice versa. All implementors will be able to
absorb changes as it makes sense for them.
Disallow access to prototype properties and methods by default.
Access to properties is always checked via
`Object.prototype.hasOwnProperty.call(parent, propertyName)`.
New runtime options:
- **allowedProtoMethods**: a string-to-boolean map of property-names that are allowed if they are methods of the parent object.
- **allowedProtoProperties**: a string-to-boolean map of property-names that are allowed if they are properties but not methods of the parent object.
```js
const template = handlebars.compile('{{aString.trim}}')
const result = template({ aString: ' abc ' })
// result is empty, because trim is defined at String prototype
```
```js
const template = handlebars.compile('{{aString.trim}}')
const result = template({ aString: ' abc ' }, {
allowedProtoMethods: {
trim: true
}
})
// result = 'abc'
```
Implementation details: The method now "container.lookupProperty"
handles the prototype-checks and the white-lists. It is used in
- JavaScriptCompiler#nameLookup
- The "lookup"-helper (passed to all helpers as "options.lookupProperty")
- The "lookup" function at the container, which is used for recursive lookups in "compat" mode
Compatibility:
- **Old precompiled templates work with new runtimes**: The "options.lookupPropery"-function is passed to the helper by a wrapper, not by the compiled templated.
- **New templates work with old runtimes**: The template contains a function that is used as fallback if the "lookupProperty"-function cannot be found at the container. However, the runtime-options "allowedProtoProperties" and "allowedProtoMethods" only work with the newest runtime.
BREAKING CHANGE:
- access to prototype properties is forbidden completely by default
fixes#1548
- add a guard to show readable syntax error for if / unless helper
- prevents against 3 different errors that can be generated by different systax errors
* Added support for iterable object in {{#each}} helper
Currently {{#each}} helper supports either arrays, or objects,
however nowadays you can define custom iterable objects by overriding
a special method called Symbol.iterator, which results in empty result
being rendered.
* improved a test for iterables in {{#each}} returning empty result
* #each helper: using ES5 instead of generator functions in tests
* #each helper: using ES5 in the helper itself
- The "lookup" helper could also be used to run a remote code execution
by manipulating the template. The same check as for regular
path queries now also is done in the "lookup"-helper
Adds multiple variable support and the ability to set statement level logging semantics.
This breaks that logger API, cleaning up the manner in which enums are set, but the other behaviors are backwards compatible.
Fixes#956