>Huh? What browser are you using???
>
>Function hoisting will always push function (and variable) declarations to the top of the scope. So the functions are visible before they are declared.
>
>http://designpepper.com/blog/drips/variable-and-function-hoisting
>
>I use this reveling module pattern in just about all my javascript code and it definitely works including for Angular modules.
>
>+++ Rick ---
>
I am using the latest Google Chrome browser. We're using v1.2.7 of AngularJs. I know that when I declared service variable on top and functions right after that, I got functions undefined error. This version of the service works now and only makes a single call:

(function () {
    'use strict';
    
    var app = angular.module('sysMgrApp');

    app.factory('invoicesService', ['$http', '$q', function($http, $q) {

        var deferredMeta = null;

        var invokeCallNumber = 0;
        // Implementation
        var getMetaData = function () {
            
            if (deferredMeta) {
                return deferredMeta.promise;
            }

            deferredMeta = $q.defer();

            if (service.metaData)
                deferredMeta.resolve(service.metaData);
            else {
                
                $http.get('/api/invoices/metadata')
                    .success(function (data) {
                        invokeCallNumber++;
                        window.console && console.log('Calling http service ' + invokeCallNumber + ' time...')
                        service.metaData = data;
                        deferredMeta.resolve(data);
                    })
                    .error(function (data, status, header, config) {

                        deferredMeta.reject(status);
                    });
            }

            return deferredMeta.promise;
        };

        var getInvoices = function (queryRequest) {
            var deferred = $q.defer();
            $http.get('/api/invoices', { params: queryRequest })
                .success(function (data) {
                    deferred.resolve(data);
                })
                .error(function (data, status, header, config) {
                    deferred.reject(status);
                });
            return deferred.promise;
        };

        var getAccountInvoices = function (queryRequest) {
            var deferred = $q.defer();
            $http.get('/api/invoices/getAccountInvoices', { params: queryRequest })
                .success(function (data) {
                    deferred.resolve(data);
                })
                .error(function (data, status, header, config) {
                    deferred.reject(status);
                });
            return deferred.promise;
        };

        var getNonFinalizedInvoices = function(queryRequest) {
            var deferred = $q.defer();
            $http.get('/api/invoices/getInvoicesToApplyFees', { params: queryRequest })
                .success(function (data) {
                    deferred.resolve(data);
                })
                .error(function (data, status, header, config) {
                    deferred.reject(status);
                });
            return deferred.promise;
        };

        var processPayments = function (transactionObject) {
            var deferred = $q.defer();
            $http.post('/api/invoices/processPayments', transactionObject)
                .success(function (data) {
                    deferred.resolve(data);
                })
                .error(function (data, status, header, config) {
                    deferred.reject(status);
                });
            return deferred.promise;
        };

        var getAccountInvoices = function (queryRequest) {
            var deferred = $q.defer();
            $http.get('/api/invoices/getAccountInvoices', { params: queryRequest })
                .success(function (data) {
                    deferred.resolve(data);
                })
                .error(function (data, status, header, config) {
                    deferred.reject(status);
                });
            return deferred.promise;
        };

        var getInvoicesToBePaid = function (queryRequest) {
            var deferred = $q.defer();
            $http.get('/api/invoices/getInvoicesToBePaid', { params: queryRequest })
                .success(function (data) {
                    deferred.resolve(data);
                })
                .error(function (data, status, header, config) {
                    deferred.reject(status);
                });
            return deferred.promise;
        };

        var getInvoice = function (id) {
            var deferred = $q.defer();
            $http.get('/api/invoices/' + id)
                .success(function (data) {
                    deferred.resolve(data);
                })
                .error(function (data, status, header, config) {
                    deferred.reject(status);
                });
            return deferred.promise;
        };

        var createInvoice = function (invoice) {
            var deferred = $q.defer();
            $http.post('/api/invoices', invoice)
                .success(function (data) {
                    deferred.resolve(data);
                })
                .error(function (data, status, header, config) {
                    deferred.reject(status);
                });
            return deferred.promise;
        };

        var saveInvoice = function (invoice) {
            var deferred = $q.defer();
            $http.put('/api/invoices', invoice)
                .success(function (data) {
                    deferred.resolve(data);
                })
                .error(function (data, status, header, config) {
                    deferred.reject(data, status);
                });
            return deferred.promise;
        };

        var deleteInvoice = function (invoiceNo) {
            var deferred = $q.defer();
            $http.delete('/api/invoices/' + invoiceNo)
                .success(function (data) {
                    deferred.resolve(data);
                })
                .error(function (data, status, header, config) {
                    deferred.reject(status);
                });
            return deferred.promise;
        };

        // Interface
        var service = {
            metaData: null,
            getMetaData: getMetaData,
            getInvoices: getInvoices,
            getAccountInvoices: getAccountInvoices,
            getInvoicesToBePaid: getInvoicesToBePaid,
            getInvoice: getInvoice,
            createInvoice: createInvoice,
            saveInvoice: saveInvoice,
            deleteInvoice: deleteInvoice,
            processPayments: processPayments
        };

        return service;
    }]);
})();

BTW, it's good thing I posted as I see that I forgot to declare a new function I just added.