stubble4js v2.0.1
Overview
Stubble4js is a javascript version of Stubble plugin for dart.
Stubble is a simplified version of the Handlebars template engine for Dart.
Example
let s = Stubble();
let template = 'Hello! I\'m {{name}}! Nice to meet you!' ;
let data = {'name': 'Stubble'};
final fn = s.compile(template);
console.log(fn(data)); // prints "Hello! I'm Stubble! Nice to meet you!"Stubble constructions
{{<path>}} - getter for property from data by it's path. If property by this path is exists then {{<path>}} will be replaced by a string representation of its value
{{$<helper_name> [<attributes>]}} - simple helper-function call. Will be replaced by a helper's result
{{#<helper_name> [<attributes>]}}<body>{{/<name>}} - block helper-function call. Also will be replaced with result of helper call. The second parameter of helper function in this case is compile function with block's 'body' as template
{{#if <condition>}}<body>{{/if}} - is statement block. If <condition> is true, will be replaced with body. Body will be compiled too.
{{#with <path>}}<body>{{/with}} - allows to pass a part of context data and work with it directly
{{#each <path>}}<body>{{/each}} - loop for a context data by path. data should has a type of array or map
Path requirements
path is a string, starts with an alphabet character and can consist of:
- lowercase or uppercase
latin characters numbersunderscoredotas path divider. It's mean thatA.B.Cwill returndata["A"]["B"]["C"], not adata["A.B.C"]
Other character are prohibited
Restrictions:
- Path can't begin with
dot - Path can't end with
dot
Helper functions
Stubble object has an registerHelper method, that allows to register special named functions that can be used in templates by names. Example:
let s = Stubble();
s.registerHelper('testHelper', (attr, fn) => {
return attr[0] * 10;
});Each registered function should have two parameters: 1. List of attributes. All helper functions attributes from it's call in template will be placed here in order left to right like they passed in helper call 2. Compiler function - available only in block-helper calls. The body of helper-function is a template of this compiler function. Example:
let s = Stubble();
stubble.registerHelper('simpleBlockHelper', (List attrs, Function fn) => {
// fn - is a result of Stubble.compile(<template>); the <template> in this example is "{{A}}; {{B}}"
let data = {'A': 'First', 'B': 'Second'};
return fn(data);
});
let fn = stubble.compile('{{#simpleBlockHelper}}{{A}}; {{B}}{{/simpleBlockHelper}}');
let res = fn({});
console.log(res); //will print 'First param; Second param'You see? stubble.compile() in the last example didn't receive any context data but {{A}}; {{B}} was transformed to First; Second. Where dit he got the data?
Helper function got this data while processing and pass it to the fn function.
Also you can remove helper function with removeHelper(String name) by name or drop them all with dropHelpers() from a concrete stubble object.
Helper name requirements
Helper name is a string, starts with an alphabet character and can consist of:
- lowercase or uppercase
latin characters numbersunderscore
Attributes requirements
Each helper function call in template can have numerous of attributes declarations.
All passed attributes will be stored in helper's attrs parameter.
There is no limits in how many attributes you can pass in helper call.
There is three available types of attributes.
path- is a path to data in context. ifpathis incorrect will return 'null'. Example:
{{$prinName data.person}}string- string value. should be placed in a double or single quotes. Example:
{{$fullName 'John' "Doe"}}number- number value. Can beintorfloat. For float use.symbol as a divider. Example:
{{$formatDate 1580193175}}IF block condition requirements
condition for #if must satisfy the following pattern - <path><operator>(<path>|<value>), where:
<path>- path to data in context<operator>- conditional operator. May be==,!=,<=,>=,<,>,<value>- test value - number, string or bool:- The number is specified without quotes.
- If the number is float, then the
dotmust be used as a separator - String values are indicated in double or single quotes
- For bool values,
trueorfalsevalues are used.
Blocks body requirements
There are no special requirements for the body at the moment, but I think the use of special characters, as well as unprintable characters, may not affect the performance of the template engine in the best way.