# Dwolla service

This service wraps the [Dwolla SDK ](https://developers.dwolla.com/sdks-tools#sdks--tools)and provides the following implementation:

* Pagination (on Customers & Transfers)
* Fields to be displayed on the UI (select)
* Search (on Customers & Transfers)
* Filters (on Customers, cf `isFilterable` flag)

{% tabs %}
{% tab title="Prototype" %}

```javascript
"use strict";

const dwolla = require('dwolla-v2');
var _ = require('lodash');

class DwollaService {
  // Allow to create a Dwolla Client based on the App Key a Secret
  constructor(appKey, appSecret, environment); 

  // Get a List of Customers based on the query (page, filter, search, sort)
  getCustomers (query);

  // Get a Customer by Id
  getCustomer (recordId);

  // Get a Customer for a local database user (by email)
  getCustomerSmartRelationship (user);

  // Get a list of Funding Sources for a customer Id
  getCustomerFundingSources (recordId, query);

  // Get a Funding Source by Id
  getFundingSource (recordId);

  // Get a list of Transfers for a customer Id
  getCustomerTransfers (recordId, query);

  // Get a Transfer by Id
  getTransfer (recordId);


}

module.exports = DwollaService;

```

{% endtab %}

{% tab title="Full implementation" %}

```javascript
"use strict";

const dwolla = require('dwolla-v2');
var _ = require('lodash');

class DwollaService {
  constructor(appKey, appSecret, environment) {
    this.client = new dwolla.Client({
      key: appKey,
      secret: appSecret,
      environment: environment // optional - defaults to production
    });
  } 

  getCustomers (query) {
    const limit = parseInt(query.page.size) || 20;
    const offset = (parseInt(query.page.number) - 1) * limit;
    const sortBy = query.sort; // Sort Parameter
    let fields = query.fields.dwollaCustomers.split(',');
    if (fields && !fields.includes('id')) {
      fields.push('id'); // id is required to get the ID
    }

    let opts = {
      search: query.search, // Search parameter
      limit,
      offset,
    };
    
    // Build the Filter parameter
    if (query.filters) {
      const filters = JSON.parse(query.filters);
      if (filters.aggregator) {
        for (const filter of filters.conditions) {
          opts[filter.field] = filter.value;
        }
      }
      else {
        opts[filters.field] = filters.value;
      }
    } 

    return this.client.auth.client()
    .then(appToken => appToken.get('customers', opts))
    .then(result => {
      if (!result.body && !result.body._embedded) return null;
      let dwollaCustomers = [];
      // Only populate the fields required by the UI
      for (const customer of result.body._embedded.customers) {
        const clonePicked = _.pick(customer, fields);
        dwollaCustomers.push(clonePicked);
      }
      const count = result.body.total;
      return { list: dwollaCustomers, count }
    });

  };

  async getCustomer (recordId) {

    return this.client.auth.client()
    .then(appToken => appToken.get(`customers/${recordId}`))
    .then(result => {
      if (!result.body) return null;
      let dwollaCustomer = result.body;
      return dwollaCustomer;
    });    
  }

  async getCustomerSmartRelationship (user) {
    return this.client.auth.client()
    .then(appToken => appToken.get('customers', { email: user.email })) // filter on email
    .then(result => {
      if (!result.body && !result.body._embedded && result.body._embedded.customers.length !== 1 ) return null;
      let dwollaCustomer = result.body._embedded.customers[0];
      // Only populate the fields required by the UI
      const clonePicked = _.pick(dwollaCustomer, ['id', 'email', 'firstName', 'lastName' ]); // We ask only for the reference field + ID
      return clonePicked;
    });
  }

  getCustomerFundingSources (recordId, query) {
    // No Pagingation available for this endpoint
    // const limit = parseInt(query.page.size) || 20;
    // const offset = (parseInt(query.page.number) - 1) * limit;

    let fields = query.fields.dwollaFundingSources.split(',');
    if (fields && !fields.includes('id')) {
      fields.push('id'); // id is required to get the ID
    }
    if (fields && !fields.includes('balance') && fields.includes('balanceReadable')) {
      fields.push('balance'); // balance is required for the amountReadable Smart Field
    }    
    return this.client.auth.client()
    .then(appToken => appToken.get(`customers/${recordId}/funding-sources`))
    .then(result => {
      if (!result.body && !result.body._embedded) return null;
      let fundingSources = [];
      // Only populate the fields required by the UI
      for (const fundingSource of result.body._embedded['funding-sources']) {
        const clonePicked = _.pick(fundingSource, fields);
        fundingSources.push(clonePicked);
      }
      const count = fundingSources.length;
      return { list: fundingSources, count }
    });

  };

  getFundingSource (recordId) {
    return this.client.auth.client()
    .then(appToken => appToken.get(`funding-sources/${recordId}`))
    .then(result => {
      if (!result.body) return null;
      let fundingSource = result.body;
      return fundingSource;
    });    
  };

  getCustomerTransfers (recordId, query) {
    const limit = parseInt(query.page.size) || 20;
    const offset = (parseInt(query.page.number) - 1) * limit;

    let fields = query.fields.dwollaTransfers.split(',');
    if (fields && !fields.includes('id')) {
      fields.push('id'); // id is required to get the ID
    }
    if (fields && !fields.includes('amount') && fields.includes('amountReadable')) {
      fields.push('amount'); // amount is required for the amountReadable Smart Field
    }

    let opts = {
      search: query.search, // Search parameter
      limit,
      offset,
    };

    return this.client.auth.client()
    .then(appToken => appToken.get(`customers/${recordId}/transfers`, opts))
    .then(result => {
      if (!result.body && !result.body._embedded) return null;
      let transfers = [];
      // Only populate the fields required by the UI
      for (const fundingSource of result.body._embedded['transfers']) {
        const clonePicked = _.pick(fundingSource, fields);
        transfers.push(clonePicked);
      }
      const count = transfers.length;
      return { list: transfers, count }
    });

  };

  getTransfer (recordId) {
    return this.client.auth.client()
    .then(appToken => appToken.get(`transfers/${recordId}`))
    .then(result => {
      if (!result.body) return null;
      let fundingSource = result.body;
      return fundingSource;
    });    
  };


}

module.exports = DwollaService;

```

{% endtab %}
{% endtabs %}