Generating Ticket PDFs in Open Event API Server

In the ordering system of Open Event API Server, there is a requirement to send email notifications to the attendees. These attendees receive the URL of the pdf of the generated ticket. On creating the order, first the pdfs are generated and stored in the preferred storage location and then these are sent to the users through the email.

Generating PDF is a simple process, using xhtml2pdf we can generate PDFs from the html. The generated pdf is then passed to storage helpers to store it in the desired location and pdf-url is updated in the attendees record.

Sample PDF

PDF Template

The templates are written in HTML which is then converted using the module xhtml2pdf.
To store the templates a new directory was created at  app/templates where all HTML files are stored. Now, The template directory needs to be updated at flask initializing app so that template engine can pick the templates from there. So in app/__init__.py we updated flask initialization with

template_dir = os.path.dirname(__file__) + "/templates"

app = Flask(__name__, static_folder=static_dir, template_folder=template_dir)

This allows the template engine to pick the templates files from this template directory.

Generating PDFs

Generating PDF is done by rendering the html template first. This html content is then parsed into the pdf

file = open(dest, "wb")

pisa.CreatePDF(cStringIO.StringIO(pdf_data.encode('utf-8')), file)

file.close()

The generated pdf is stored in the temporary location and then passed to storage helper to upload it.

uploaded_file = UploadedFile(dest, filename)

upload_path = UPLOAD_PATHS['pdf']['ticket_attendee'].format(identifier=get_file_name())

new_file = upload(uploaded_file, upload_path)

This generated pdf path is returned here

Rendering HTML and storing PDF

for holder in order.ticket_holders:

  if holder.id != current_user.id:

      pdf = create_save_pdf(render_template('/pdf/ticket_attendee.html', order=order, holder=holder))

  else:

      pdf = create_save_pdf(render_template('/pdf/ticket_purchaser.html', order=order))

  holder.pdf_url = pdf

  save_to_db(holder)

The html is rendered using flask template engine and passed to create_save_pdf and link is updated on the attendee record.

Sending PDF on email

These pdfs are sent as a link to the email after creating the order. Thus a ticket is sent to each attendee and a summarized order details with attendees to the purchased.

send_email(

  to=holder.email,

  action=TICKET_PURCHASED_ATTENDEE,

  subject=MAILS[TICKET_PURCHASED_ATTENDEE]['subject'].format(

      event_name=order.event.name,

      invoice_id=order.invoice_number

  ),

  html= MAILS[TICKET_PURCHASED_ATTENDEE]['message'].format(

      pdf_url=holder.pdf_url,

      event_name=order.event.name

  )

)

References

  1. Readme – xhtml2pdf
    https://github.com/xhtml2pdf/xhtml2pdf/blob/master/README.rst
  2. Using xhtml2pdf and create pdfs
    https://micropyramid.com/blog/generating-pdf-files-in-python-using-xhtml2pdf/

 

Discount Codes in Open Event Server

The Open Event System allows usage of discount codes with tickets and events. This blogpost describes what types of discount codes are present and what endpoints can be used to fetch and update details.

In Open Event API Server, each event can have two types of discount codes. One is ‘event’ discount code, while the other is ‘ticket’ discount code. As the name suggests, the event discount code is an event level discount code and the ticket discount code is ticket level.

Now each event can have only one ‘event’ discount code and is accessible only to the server admin. The Open Event server admin can create, view and update the ‘event’ discount code for an event. The event discount code followsDiscountCodeEvent Schema. This schema is inherited from the parent class DiscountCodeSchemaPublic. To save the unique discount code associated with an event, the event model’s discount_code_id field is used.

The ‘ticket’ discount is accessible by the event organizer and co-organizer. Each event can have any number of ‘ticket’ discount codes. This follows the DiscountCodeTicket schema, which is also inherited from the same base class ofDiscountCodeSchemaPublic. The use of the schema is decided based on the value of the field ‘used_for’ which can have the value either ‘events’ or ‘tickets’. Both the schemas have different relationships with events and marketer respectively.

We have the following endpoints for Discount Code events and tickets:
‘/events/<int:event_id>/discount-code’
‘/events/<int:event_id>/discount-codes’

The first endpoint is based on the DiscountCodeDetail class. It returns the detail of one discount code which in this case is the event discount code associated with the event.

The second endpoint is based on the DiscountCodeList class which returns a list of discount codes associated with an event. Note that this list also includes the ‘event’ discount code, apart from all the ticket discount codes.

class DiscountCodeFactory(factory.alchemy.SQLAlchemyModelFactory):
   class Meta:
       model = DiscountCode
       sqlalchemy_session = db.session
event_id = None
user = factory.RelatedFactory(UserFactory)
user_id = 1


Since each discount code belongs to an event(either directly or through the ticket), the factory for this has event as related factory, but to check for 
/events/<int:event_id>/discount-code endpoint we first need the event and then pass the discount code id to be 1 for dredd to check this. Hence, event is not included as a related factory, but added as a different object every time a discount code object is to be used.

@hooks.before("Discount Codes > Get Discount Code Detail of an Event > Get Discount Code Detail of an Event")
def event_discount_code_get_detail(transaction):
   """
   GET /events/1/discount-code
   :param transaction:
   :return:
   """
   with stash['app'].app_context():
       discount_code = DiscountCodeFactory()
       db.session.add(discount_code)
       db.session.commit()
       event = EventFactoryBasic(discount_code_id=1)
       db.session.add(event)
       db.session.commit()


The other tests and extended documentation can be found 
here.

References:

Open Event Server: Getting The Identity From The Expired JWT Token In Flask-JWT

The Open Event Server uses JWT based authentication, where JWT stands for JSON Web Token. JSON Web Tokens are an open industry standard RFC 7519 method for representing claims securely between two parties. [source: https://jwt.io/]

Flask-JWT is being used for the JWT-based authentication in the project. Flask-JWT makes it easy to use JWT based authentication in flask, while on its core it still used PyJWT.

To get the identity when a JWT token is present in the request’s Authentication header , the current_identity proxy of Flask-JWT can be used as follows:

@app.route('/example')
@jwt_required()
def example():
   return '%s' % current_identity

 

Note that it will only be set in the context of function decorated by jwt_required(). The problem with the current_identity proxy when using jwt_required is that the token has to be active, the identity of an expired token cannot be fetched by this function.

So why not write a function on our own to do the same. A JWT token is divided into three segments. JSON Web Tokens consist of three parts separated by dots (.), which are:

  • Header
  • Payload
  • Signature

The first step would be to get the payload, that can be done as follows:

token_second_segment = _default_request_handler().split('.')[1]

 

The payload obtained above would still be in form of JSON, it can be converted into a dict as follows:

payload = json.loads(token_second_segment.decode('base64'))

 

The identity can now be found in the payload as payload[‘identity’]. We can get the actual user from the paylaod as follows:

def jwt_identity(payload):
   """
   Jwt helper function
   :param payload:
   :return:
   """
   return User.query.get(payload['identity'])

 

Our final function will now be something like:

def get_identity():
   """
   To be used only if identity for expired tokens is required, otherwise use current_identity from flask_jwt
   :return:
   """
   token_second_segment = _default_request_handler().split('.')[1]
   missing_padding = len(token_second_segment) % 4
   payload = json.loads(token_second_segment.decode('base64'))
   user = jwt_identity(payload)
   return user

 

But after using this function for sometime, you will notice that for certain tokens, the system will raise an error saying that the JWT token is missing padding. The JWT payload is base64 encoded, and it requires the payload string to be a multiple of four. If the string is not a multiple of four, the remaining spaces can pe padded with extra =(equal to) signs. And since Python 2.7’s .decode doesn’t do that by default, we can accomplish that as follows:

missing_padding = len(token_second_segment) % 4

# ensures the string is correctly padded to be a multiple of 4
if missing_padding != 0:
   token_second_segment += b'=' * (4 - missing_padding)

 

Related links:

Showing location response in SUSI.AI bots

SUSI.AI has a capability to tell the basic information about a location, it is asked for. Along with the basic information about that place, it shows a map (i.e. open street map) pointing to that location. The task at hand is to inculcate this “location” feature to the SUSI.AI messenger bots. The SUSI Tweetbot and SUSI Fbbot are used as examples in this blog.

Let’s first check on what response do we get, when a person asks a query like “where is london” to the SUSI API. Along with the basic information about that location, the result as shown below has the type of reply (i.e. map), latitude, longitude and a link to the open street map.

"actions": [
      {
        "type": "answer",
        "language": "en",
        "expression": "Ludhiana is a city and a municipal corporation in Ludhiana district in the Indian state of Punjab, and is the largest city north of Delhi."
      },
      {
        "type": "anchor",
        "link": "https://www.openstreetmap.org/#map=13/30.912040570244187/75.85379021980509",
        "text": "Here is a map",
        "language": "en"
      },
      {
        "type": "map",
        "latitude": "30.912040570244187",
        "longitude": "75.85379021980509",
        "zoom": "13",
        "language": "en"
      }
    ]

The response for a location type query has these 3 main parts:

  1. Clickable static map image.
  2. A basic information of the place asked about.
  3. The link i.e. when the static map image is clicked it should redirect to the corresponding map location.

Let’s try to make up with the 1st part of the response i.e. Static map image.

The map quest API is used to result in a static map image of the location. We need an API key to access the map quest API, which can be requested from their developer site.

Along with that we need the latitude and longitude of the location at hand.

The SUSI API’s response helps us to get the latitude value:

// if body represents the response object 
var lat = body.answers[0].actions[2].latitude;

And the longitude value:

var lon = body.answers[0].actions[2].longitude;

Using the three values that are API key, latitude and longitude, the static image is rendered by this link:

var static_image_url = "https://open.mapquestapi.com/staticmap/v4/getmap?key=API_KEY&size=600,400&zoom=13&center="+lat+","+lon;

The second part is, basic information about the place asked, can be fetched from:

// if body is the JSON response object from SUSI API
var mapMessage = body.answers[0].actions[0].expression;

The link to the map location can be easily fetched from the SUSI API’s response:

var link = body.answers[0].actions[1].link;

As all the three parts are ready, let’s look on how to render them on the SUSI.AI bot’s screen.

Facebook:

Sending a generic template message object:

message = {
        "type":"template",
        "payload":{
                    "template_type":"generic",
                    "elements":[{
                        "title": mapMessage,
                       "image_url": static_image_url,
                       "Item_url": link
                    }]
        }
};

sendTextMessage(sender, message, 1);

Twitter:

The Twitter API does not need a static image of the map to be rendered. It does that work for us. We just need to send an event to the Twitter API with the message data object constituting of the map message, the latitude and longitude values:

"message_data": {
            "text": mapMessage,
            "attachment": {
                "type": "location",
                "location": {
                    "type": "shared_coordinate",
                    "shared_coordinate": {
                        "coordinates": {
                            "type": "Point",
                            "coordinates": [lon, lat]
                        }
                    }
                }
            }
}

Resources:

  1. Speed up customer service with quick replies and welcome messages by Ian Cairns from Twitter blog.
  2. Drive discovery of bots and other customer experiences in direct messages by By Travis Lull from Twitter blog.
  3. By Seth Rosenberg from Facebook developers blogLink Ads to Messenger, Enhanced Mobile Websites, Payments and More.

Creating Dynamic Forms Using Custom-Form API in Open Event Front-end

In Open Event Front-end allows the the event creators to customise the sessions & speakers forms which are implemented on the Orga server using custom-form API. While event creation the organiser can select the forms fields which will be placed in the speaker & session forms.

In this blog we will see how we created custom forms for sessions & speakers using the custom-form API. Lets see how we did it.

Retrieving all the form fields

Each event has custom form fields which can be enabled on the sessions-speakers page, where the organiser can include/exclude the fields for speakers & session forms which are used by the organiser and speakers.

return this.modelFor('events.view').query('customForms', {});

We pass return the result of the query to the new session route where we will create a form using the forms included in the event.

Creating form using custom form API

The model returns an array of all the fields related to the event, however we need to group them according to the type of the field i.e session & speaker. We use lodash groupBy.

allFields: computed('fields', function() {
  return groupBy(this.get('fields').toArray(), field => field.get('form'));
})

For session form we run a loop allFields.session which is an array of all the fields related to session form. We check if the field is included and render the field.

{{#each allFields.session as |field|}}
  {{#if field.isIncluded}}
    <div class="field">
      <label class="{{if field.isRequired 'required'}}" for="name">{{field.name}}</label>
      {{#if (or (eq field.type 'text') (eq field.type 'email'))}}
        {{#if field.isLongText}}
          {{widgets/forms/rich-text-editor textareaId=(if field.isRequired (concat 'session_' field.fieldIdentifier '_required'))}}
        {{else}}
          {{input type=field.type id=(if field.isRequired (concat 'session_' field.fieldIdentifier '_required'))}}
        {{/if}}
      {{/if}}
    </div>
  {{/if}}
{{/each}}

We also use a unique id for all the fields for form validation. If the field is required we create a unique id as `session_fieldName_required` for which we add a validation in the session-speaker-form component. We also use different components for different types of fields eg. for a long text field we make use of the rich-text-editor component.

Thank you for reading the blog, you can check the source code for the example here.

Resources

Marker Click Management in Android Google Map API Version 2

We could display a marker on Google map to point to a particular location. Although it is a simple task sometimes we need to customise it a bit more. Recently I customised marker displayed in Connfa app displaying the location of the sessions on the map loaded from Open Event format. In this blog manipulation related to map marker is explored.

Markers indicate single locations on the map. You can customize your markers by changing the default colour, or replace the marker icon with a custom image. Info windows can provide additional context to a marker. You can place a marker on the map by using following code.

MarkerOptions marker = new MarkerOptions().position(new LatLng(latitude, longitude)).title("Dalton Hall");
googleMap.addMarker(marker);

But as you can see this may not be enough, we need to do operations on clicking the marker too, so we define them in the Marker Click Listener. We declare marker null initially so we check if the marker colour is changed previously or not.

private Marker previousMarker = null;

We check if the marker is initialized to change its colour again to initial colour, we can do other related manipulation like changing the map title here,

Note: the first thing that happens when a marker is clicked or tapped is that any currently showing info window is closed, and the GoogleMap.OnInfoWindowCloseListener is triggered. Then the OnMarkerClickListener is triggered. Therefore, calling isInfoWindowShown() on any marker from the OnMarkerClickListener will return false.

mGoogleMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
   @Override
   public boolean onMarkerClick(Marker marker) {
       String locAddress = marker.getTitle();
       fillTextViews(locAddress);
       if (previousMarker != null) {
           previousMarker.setIcon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
       }
       marker.setIcon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_BLUE));
       previousMarker = marker;

       return true;
   }
});

It’s possible to customize the colour of the default marker image by passing a BitmapDescriptor object to the icon() method. You can use a set of predefined colours in the BitmapDescriptorFactory object, or set a custom marker colour with the BitmapDescriptorFactory.defaultMarker(float hue) method. The hue is a value between 0 and 360, representing points on a colour wheel. We use red colour when the marker is not clicked and blue when it is clicked so a user knows which one is clicked.

To conclude you can use an OnMarkerClickListener to listen for click events on the marker. To set this listener on the map, call GoogleMap.setOnMarkerClickListener(OnMarkerClickListener). When a user clicks on a marker, onMarkerClick(Marker) will be called and the marker will be passed through as an argument. This method returns a boolean that indicates whether you have consumed the event (i.e., you want to suppress the default behaviour). If it returns false, then the default behaviour will occur in addition to your custom behaviour. The default behaviour for a marker click event is to show its info window (if available) and move the camera such that the marker is centered on the map.

The final result looks like this, so you the user can see which marker is clicked as its colour is changed,

   

 

References:

  • Google Map APIs Documentation – https://developers.google.com/maps/documentation/android-api/marker

Keeping Order of tickets in Event Wizard in Sync with API on Open Event Frontend

This blog article will illustrate how the various tickets are stored and displayed in order the event organiser decides  on  Open Event Frontend and also, how they are kept in sync with the backend.

First we will take a look at how the user is able to control the order of the tickets using the ticket widget.

{{#each tickets as |ticket index|}}
  {{widgets/forms/ticket-input ticket=ticket
  timezone=data.event.timezone
  canMoveUp=(not-eq index 0)
  canMoveDown=(not-eq ticket.position (dec
  data.event.tickets.length))
  moveTicketUp=(action 'moveTicket' ticket 'up')
  moveTicketDown=(action 'moveTicket' ticket 'down')
  removeTicket=(confirm 'Are you sure you  wish to delete this 
  ticket ?' (action 'removeTicket' ticket))}}
{{/each}}

The canMoveUp and canMoveDown are dynamic properties and are dependent upon the current positions of the tickets in the tickets array.  These properties define whether the up or down arraow or both should be visible alongside the ticket to trigger the moveTicket action.

There is an attribute called position in the ticket model which is responsible for storing the position of the ticket on the backend. Hence it is necessary that the list of the ticket available should always be ordered by position. However, it should be kept in mind, that even if the position attribute of the tickers is changed, it will not actually change the indices of the ticket records in the array fetched from the API. And since we want the ticker order in sync with the backend, i.e. user shouldn’t have to refresh to see the changes in ticket order, we are going to return the tickets via a computed function which sorts them in the required order.

tickets: computed('data.event.tickets.@each.isDeleted', 'data.event.tickets.@each.position', function() {
   return this.get('data.event.tickets').sortBy('position').filterBy('isDeleted', false);
 })

The sortBy method ensures that the tickets are always ordered and this computed property thus watches the position of each of the tickets to look out for any changes. Now we can finally define the moveTicket action to enable modification of position for tickets.

moveTicket(ticket, direction) {
     const index = ticket.get('position');
     const otherTicket = this.get('data.event.tickets').find(otherTicket => otherTicket.get('position') === (direction === 'up' ? (index - 1) : (index + 1)));
     otherTicket.set('position', index);
     ticket.set('position', direction === 'up' ? (index - 1) : (index + 1));
   }

The moveTicket action takes two arguments, ticket and direction. It temporarily stores the position of the current ticket and the position of the ticket which needs to be swapped with the current ticket.Based on the direction the positions are swapped. Since the position of each of the tickets is being watched by the tickets computed array, the change in order becomes apparent immediately.

Now when the User will trigger the save request, the positions of each of the tickets will be updated via a PATCH or POST (if the ticket is new) request.

Also, the positions of all the tickets maybe affected while adding a new ticket or deleting an existing one. In case of a new ticket, the position of the new ticket should be initialised while creating it and it should be below all the other tickets.

addTicket(type, position) {
     const salesStartDateTime = moment();
     const salesEndDateTime = this.get('data.event.startsAt');
     this.get('data.event.tickets').pushObject(this.store.createRecord('ticket', {
       type,
       position,
       salesStartsAt : salesStartDateTime,
       salesEndsAt   : salesEndDateTime
     }));
   }

Deleting a ticket requires updating positions of all the tickets below the deleted ticket. All of the positions need to be shifted one place up.

removeTicket(deleteTicket) {
     const index = deleteTicket.get('position');
     this.get('data.event.tickets').forEach(ticket => {
       if (ticket.get('position') > index) {
         ticket.set('position', ticket.get('position') - 1);
       }
     });
     deleteTicket.deleteRecord();
   }

The tickets whose position is to be updated are filtered by comparison of their position from the position of the deleted ticket.

Resources

Implementing Order Statistics API on Tickets Route in Open Event Frontend

The order statistics API endpoints are used to display the statistics related to tickets, orders, and sales. It contains the details about the total number of orders, the total number of tickets sold and the amount of the sales. It also gives the detailed information about the pending, expired, placed and completed orders, tickets, and sales.

This article will illustrate how the order statistics can be displayed using the Order Statistics API in Open Event Frontend. The primary end point of Open Event API with which we are concerned with for statistics is

GET /v1/events/{event_identifier}/order-statistics

First, we need to create a model for the order statistics, which will have the fields corresponding to the API, so we proceed with the ember CLI command:

ember g model order-statistics-tickets

Next, we need to define the model according to the requirements. The model needs to extend the base model class. The code for the model looks like this:

import attr from 'ember-data/attr';
import ModelBase from 'open-event-frontend/models/base';

export default ModelBase.extend({
  orders  : attr(),
  tickets : attr(),
  sales   : attr()
});

As we need to display the statistics related to orders, tickets, and sales so we have their respective variables inside the model which will fetch and store the details from the API.

Now, after creating a model, we need to make an API call to get the details. This can be done using the following:

return this.modelFor('events.view').query('orderStatistics', {});

Since the tickets route is nested inside the event.view route so, first we are getting the model for event.view route and then we’re querying order statistics from the model.

The complete code can be seen here.

Now, we need to call the model inside the template file to display the details. To fetch the total orders we can write like this

{{model.orders.total}}

 

In a similar way, the total sales can be displayed like this.

{{model.sales.total}}

 

And total tickets can be displayed like this

{{model.tickets.total}}

 

If we want to fetch other details like the pending sales or completed orders then the only thing we need to replace is the total attribute. In place of total, we can add any other attribute depending on the requirement. The complete code of the template can be seen here.

The UI for the order statistics on the tickets route looks like this.

Fig. 1: The user interface for displaying the statistics

The complete source code can be seen here.

Resources:

Implementing Pages API in Open Event Frontend

The pages endpoints are used to create static pages which such as about page or any other page that doesn’t need to be updated frequently and only a specific content is to be shown. This article will illustrate how the pages can be added or removed from the /admin/content/pages route using the pages API in Open Event Frontend. The primary end point of Open Event API with which we are concerned with for pages is

GET /v1/pages

First, we need to create a model for the pages, which will have the fields corresponding to the API, so we proceed with the ember CLI command:

ember g model page

Next, we need to define the model according to the requirements. The model needs to extend the base model class. The code for the page model looks like this:

import attr from 'ember-data/attr';
import ModelBase from 'open-event-frontend/models/base';

export default ModelBase.extend({
  name        : attr('string'),
  title       : attr('string'),
  url         : attr('string'),
  description : attr('string'),
  language    : attr('string'),
  index       : attr('number', { defaultValue: 0 }),
  place       : attr('string')
});

As the page will have name, title, url which will tell the URL of the page, the language, the description, index and the place of the page where it has to be which can be either a footer or an event.

The complete code for the model can be seen here.

Now, after creating a model, we need to make an API call to get and post the pages created. This can be done using the following:

return this.get('store').findAll('page');

The above line will check the store and find all the pages which have been cached in and if there is no record found then it will make an API call and cache the records in the store so that when called it can return it immediately.

Since in the case of pages we have multiple options like creating a new page, updating a new page, deleting an existing page etc. For creating and updating the page we have a form which has the fields required by the API to create the page.  The UI of the form looks like this.

Fig. 1: The user interface of the form used to create the page.

Fig. 2: The user interface of the form used to update and delete the already existing page

The code for the above form can be seen here.

Now, if we click the items which are present in the sidebar on the left, it enables us to edit and update the page by displaying the information stored in the form and then the details be later updated on the server by clicking the Update button. If we want to delete the form we can do so using the delete button which first shows a pop up to confirm whether we actually want to delete it or not. The code for displaying the delete confirmation pop up looks like this.

<button class="ui red button" 
{{action (confirm (t 'Are you sure you would like to delete this page?') (action 'deletePage' data))}}>
{{t 'Delete'}}</button>

 

The code to delete the page looks like this

deletePage(data) {
    if (!this.get('isCreate')) {
      data.destroyRecord();
      this.set('isFormOpen', false);
    }
  }

In the above piece of code, we’re checking whether the form is in create mode or update mode and if it’s in create mode then we can destroy the record and then close the form.

The UI for the pop up looks like this.

Fig.3: The user interface for delete confirmation pop up

The code for the entire process of page creation to deletion can be checked here

To conclude, this is how we efficiently do the process of page creation, updating and deletion using the Open-Event-Orga pages API  ensuring that there is no unnecessary API call to fetch the data and no code duplication.

Resources:

Implementing Event Copy API in Open Event Frontend

In Open Event Frontend, we give the organizer a facility to create a copy of the event by copying it and making the modifications he wants to a particular event. Thus, it is easy for the organizer to create multiple events with same sponsors, sessions, etc. For this, we implemented the event copy API in frontend.
We achieved the copy of events as follows:
Since the event copy API is application/json type, we used the simple GET and POST requests to copy the event rather than using the ember data. For this, we use the loader service which is injected throughout the app. To copy the event we have given a “Copy” button which looks as follows:

 <button class="ui button {{if isCopying 'loading'}}" {{action 'copyEvent'}} disabled={{isCopying}}>
    <i class="copy icon"></i>
        {{t 'Copy'}}
 </button>

Thus, we trigger an action ‘copyEvent’ on clicking the Copy button. The action is defined in controller as follows:

 copyEvent() {
      this.set('isCopying', true);
      this.get('loader')
        .post(`events/${this.get('model.id')}/copy`, {})
        .then(copiedEvent => {
          this.transitionToRoute('events.view.edit', copiedEvent.identifier);
          this.get('notify').success(this.l10n.t('Event copied successfully'));
        })
        .catch(() => {
          this.get('notify').error(this.l10n.t('Copying of event failed'));
        })
        .finally(() => {
          this.set('isCopying', false);
        });
    }

The endpoint to copy the event as defined in our API is:

POST : /v1/events/{identifier}/copy
Content-Type: application/vnd.api+json
Authorization: JWT <Auth Key>
Request body: {}

Thus, we make a post request to the given URL by passing the event id of the event to be copied and the request body to be an empty object. Thus, on successful response from the server, we get the new event id for which the event info is same. We then redirect the user to the edit details route where he can change the info he wants.
Thus, we copy the event in Open Event Frontend.

Resources: Docs on loader service in Ember JS