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falcor-shapes

falcor-shapes Build Status

falcor-shapes is a convenience function for generating Falcor PathSets.

It converts a "Shape" into an array of Falcor PathSets.

For example:

{
 name: {
    first: true,
    last: true
  },
  location: {
    city: true,
    region: true,
    country: true
  }
}

becomes

[
  [ 'name', 'first' ],
  [ 'name', 'last' ],
  [ 'location', 'city' ],
  [ 'location', 'region' ],
  [ 'location', 'country' ]
]

Install

npm install falcor-shapes

Background

I built this function while playing around with falcor for the first time a few days ago. I found it easier to think of data in terms of a hierarchical structure rather than a list of string paths.

It also allows you to split up the list of what fields you need across multiple files (similar to GraphQL/Relay in React).

What is a "Shape"?

A shape is a recursive structure that resembles the JavaScript structure you're expecting. Shapes are simply JavaScript objects with keys and values. If a value is a nested JavaScript object, it will be expanded into multiple PathSets.

  • { <key>: true } is a leaf value, and becomes the path [ '<key>' ]
  • { <key>: <Shape> } recurses
  • $ is a special key that expects an array: { $: [ <range>, <Shape> ] } and becomes [ <range>, <Shape> ]

Example:

{
  people: {
    length: true,
    $: [
      {from: 0, to: 100},
      {
        name: {
          first: true,
          last: true
        },
        age: true
      }
    ]
  }
}

becomes:

[ 'people', 'length' ],
[ 'people', { from: 0, to: 100 }, 'name', 'first' ],
[ 'people', { from: 0, to: 100 }, 'name', 'last' ],
[ 'people', { from: 0, to: 100 }, 'age' ]

See more examples in test/test.js.

Usage

var shapeToSet = require('falcor-shapes')
 
var sets = shapeToSet({
  people: {
    length: true,
    $: [
      {from: 0, to: 100},
      {
        name: {
          first: true,
          last: true
        },
        age: true
      }
    ]
  }
})
 
// falcor's model.get expects each path as separate arguments, so we need to call 'apply' 
model.get.apply(model, sets).then( ... )

We can make a helper function to simplify this:

function getWithShape(shape) {
  return model.get.apply(model, shape)
}
 
getWithShape({
  people: {
    length: true,
    $: [
      {from: 0, to: 100},
      {
        name: {
          first: true,
          last: true
        },
        age: true
      }
    ]
  }
}).then( ... )

Development and Test

# Clone the repo
git clone git@github.com:marcello3d/falcor-shapes.git
 
# Install dependencies
npm install
 
# Run tests
npm test

Contributing

Feel free to submit pull requests!

License

zlib