JS-DATA

JS-DATA KEY TERMS

- Front End Model Layer 

- RESTful Resources

- Framework-agnostic data store 

- Relations

- Twitter Bootstrap for Front Data Modeling 

- Schemata & Validation

- Custom Instance Behavior

- Promises 

Front End Model Layers

- mongoose is to our database what front end model layers are to     our RESTful endpoints

- Creating instances of a class: $http.get() vs Cohort.find()

    //regular old data
    $http.get()  


    // data that becomes an 
    //instance of a configured Class

    Cohort.find()   

    //under the hood 
    return response.data.map(function(item){
        return Cohort.createInstance(item)
    })

angular.module('myApp')
  .config(function(DSHttpAdapter){
    // any call to the DB prepended by '/api'
    DSHttpAdatperProvider.defaults.basePath = '/api'
  })
  .factory('Cohort', function(DS) {
    // register our resource with the Data Store 
    var Cohort = DS.defineResource({
        name: 'cohorts', 
        idAttribute: '_id'
    })

    return Cohort;
})

THE DS Object

- DS is a constructor function that creates instances of the registered resource definition

- Takes a configuration object and returns a resource 

- DSHttpAdapter, DSFirebaseAdapter, etc

In Memory Cache

- DS not only turns our data into instances, it injects into an in-memory cache 

 var Cohort = DS.defineResource({
     name: 'cohorts', 
     idAttribute: '_id'
 })
 
 Cohort.find()
 .then(function(data){
    return data.map(function(datum){
        return Cohort.createInstance(datum)
    })
 })
 .then(function(instances){
    // inject your data into the in memory cache 
    // for retrieval at a later time
    Cohort.inject(instances)
 })
       

​JS-DATA REST Assumptions

1. GET /<resource>/:id                        returns an object, { id: 1 }
2. GET /<resource>               returns an array of objects, [{ id: 1 }]
3. POST /<resource> { payload }           creates & returns an item 
4. PUT /<resource>/:id { payload}            updates & returns item
5. -DELETE /<resource>/:id                             deletes a single item 
6. DELETE /<resource>                                 deletes a collection of items 

ASYNC: pinging your database

1. Cohort.findAll() -->  GET '/api/cohorts/'

2. Cohort.find('1')  -- > GET '/api/cohorts/1'

3. Cohort.create(data) --> POST '/api/cohorts/'

SYNC: modifying the data store 

1. Cohort.getAll()  

2. Cohort.get() 

3. Cohort.inject(data)

var getCohorts = function(){
    var cohortsArr; 
    // first check if there's anything in the cache
    if (cohortsArr = Cohort.getAll()) return cohortsArr; 
    // if nothing in the cache, ping the database
    else return Cohort.find()
}

 // /api/workshops/:workshopId/concepts/:conceptId
  .factory('Concept', function (DS) {
    return DS.defineResource({
        name: 'concepts',
        idAttribute: '_id',
        relations: {
          hasMany: {
            actions: {
              foreignKey: 'concept', 
              localKey: '_id'
            }
          },
          belongsTo: {
            workshops: {
              parent: true, 
              localKey: '_id', 
              localField: 'workshops'
            }
          } 
        }
    });

RELATIONS