Datastore One-to-Many Google App Engine

Question

I'm struggling to display my array items in the template. Just started with Entity relationships in GAE and I'm not finding suitable solutions on SO. Do i have to perform a query first in my handler. if so, how coz I'm struggling with the logic.

Datastore

Project

entities example display

Datastore

Employees

entities example display

Project.py

class Project(ndb.Model):

    projectID = ndb.IntegerProperty(required=True)

    title = ndb.StringProperty(required=True)

    description = ndb.StringProperty(required=True)

    startAt = ndb.DateTimeProperty(indexed=True)

    endAt = ndb.DateTimeProperty()

    isFullDay = ndb.BooleanProperty()

    days = ndb.KeyProperty(kind='CompanyDay', repeated=True)

    employees = ndb.KeyProperty(kind='Employees', repeated=True)

    client = ndb.KeyProperty(kind='Client')



class Employees(ndb.Model):

    name = ndb.StringProperty()

    role = ndb.StringProperty()

template

data
is fetched from the backend through angular's http
service

 <md-content  class="md-padding projects" layout="row" layout-wrap>

        <md-card ng-repeat="data in controller.projects" flex="20" ng-click="editProject(data)">

            <img src="" alt="">

            <md-card-content>

                <div class="project-info">

                    <h2 class="md-title">{{ data.title }}</h2>

                    <p>{{ data.description }}</p>

                    <p>{{ data.employees }}</p>



                </div>

            </md-card-content>

        </md-card>

    </md-content>

python code that responds to /comments

class commentsJsonHandler(webapp2.RequestHandler):

@classmethod

def route(cls):

    """

    name: index, template: /

    """

    return webapp2.Route('/comments', handler=cls, name='_commments_')



def get(self):  

    projects = Project.query()



    def date_handler(obj):

        print obj

        if isinstance(obj, datetime):

            return obj.isoformat()

        else:

            return str(obj)



    self.response.out.write(json.dumps([dict(proj.to_dict(), **dict(id=proj.key.id())) for proj in projects], default=date_handler))

from angular - code that reguests from server

 var vm = this;

    vm.projects = [];

    $http.get('/comments')

        .then(function(result) {

            console.log(result);

            vm.projects = result.data;

         });

Displaying employees as from the datastore.

Answer 1

You could change your date_handler to handle ndb.Key to properly render your Employee collection in your returned json

def date_handler(obj):
    print obj
    if isinstance(obj, datetime):
        return obj.isoformat()
    elif isinstance(obj, ndb.Key):
      return obj.get().to_dict()
    else:
        return str(obj)

You may want to change the name of this method as it is not just doing date_handling any more

Datastore One-to-Many Google App Engine

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