https://github.com/hellocomet/handlespy

A Node.js library to inspect the required variables in a handlebars template
https://github.com/hellocomet/handlespy

Last synced: 3 months ago
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A Node.js library to inspect the required variables in a handlebars template

• Host: GitHub
• URL: https://github.com/hellocomet/handlespy
• Owner: hellocomet
• Created: 2019-05-10T11:36:14.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2019-06-05T09:34:39.000Z (over 5 years ago)
• Last Synced: 2024-10-08T22:41:58.036Z (3 months ago)
• Language: JavaScript
• Size: 51.8 KB
• Stars: 3
• Watchers: 7
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Handlespy

Handlespy is a simple Node.js library to inspect Handlebars templates for required variables. This is accomplished by iterating over the AST produced by the `handlebars` parser.

It also provides a helper to verify that a payload contains all required variables.

## Installation

```sh

npm install handlespy

# or

yarn add handlespy

```

## Usage

```javascript

const { getRequiredVariables, getMissingVariables } = require('handlespy')

const template = `

A simple handlebar template containing a variable ({{someVariable}}) and a loop :

{{#each someLoop}}

- {{someProperty}}

{{/each}}

`

const requiredVariables = getRequiredVariables(template)

/*

[

  'someVariable',

  { loopVariable: 'someLoop', properties: [ 'someProperty' ] }

]

*/

const completePayload = {

  someVariable: 'Test',

  someLoop: [{ someProperty: 'Another test' }]

}

const incompletePayload = {

  // missing someVariable,

  someLoop: [

    { someProperty: 'Another test' },

    { unsupportedProperty: 'Final test' }, // someLoop[1] is missing the required someProperty

  ]

}

const test1 = getMissingVariables(completePayload, requiredVariables)

// []

const test2 = getMissingVariables(incompletePayload, requiredVariables)

/*

[ 'someVariable', 'someLoop[1].someProperty' ]

*/

```

## API

### getRequiredVariables

- expects : (String) A handlebars template

- returns : (Array) The required variables

Each item in the returned array can either be a string (denoting a simple variable), or an object (denoting an `each` loop) containing the following :

- loopVariable (String) : the name of the variable

- properties (Array) : the required properties on the looped variable

  - *loops can be nested, so `properties` can contain another object with `loopVariable` and `properties`*

  - *if only `this` is used in the loop, `properties` is an empty array*

### getMissingVariables

- expects :

  - (Object) The payload to check

  - One of the following :

    - (String) A handlebars template

    - (Array) or a required variables specification as returned by `getRequiredVariables`

- returns : (Array) The missing variables

Each item in the returned array is a string, which can be of either of the following formats :

- `missingVariable` : variable is missing in the payload

- `missingArray[]` : a variable, which is used in an `each` loop, is present in the payload but isn't an array

- `item[2].missingProperty` : an item in an array is missing a required properties

## Contributing

If you find any bug or missing functionality in handlespy, don't hesitate to create an issue ! If you can provide a PR with a failing test, this would help greatly in solving the issue :)

***

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