Tell Me More: About the Code

1global class QuickOrderController{
2    public static List<Merchandise__c> merchandise;
3    public static Line_Item__c quickOrder;
4    
5    
6    public QuickOrderController(ApexPages.
7        StandardController controller){  
8    }
9    
10    @RemoteAction
11    global static List<Merchandise__c> findWarehouses(String accId,
12        String merchName, String warehouseDist){
13         merchandise = new List<Merchandise__c>();
14         String queryString = '';
15         String queryName = '%' + merchName + '%';
16         
17         Account acc = [Select Location__Longitude__s, 
18         Location__Latitude__s, Name, Id 
19         from Account where Id =: accId];
20         
21         //Finds warehouses nearby if you have location 
22         //specified on the Account
23         if(acc.Location__Latitude__s != null && 
24             acc.Location__Longitude__s != null){
25             queryString = 'SELECT Id, (SELECT Id, Name, Quantity__c,
26                 Warehouse__r.Name, Warehouse__r.Id, 
27                 Warehouse__r.Street_Address__c, 
28                 Warehouse__r.City__c '+
29                 'FROM Merchandise__r WHERE Name 
30                 like :queryName) '
31                 +'FROM Warehouse__c WHERE '
32                 +'DISTANCE(Location__c, GEOLOCATION('
33                 +acc.Location__Latitude__s+','
34                 +acc.Location__Longitude__s+'), \'mi\')';
35             if(warehouseDist != null){
36                 queryString += ' <'+ warehouseDist;
37             }
38             
39         }
40         //If no location defined on the Account, this will run 
41         //query against the merchandise name only
42         else {
43             queryString = 'SELECT Id, Name, 
44                 Location__Longitude__s, 
45                 Location__Latitude__s, '
46                 +'(SELECT Id, Name, Warehouse__r.Name, 
47                 Quantity__c 
48                 FROM Merchandise__r WHERE Name 
49                 like :queryName) '
50                 +'FROM Warehouse__c limit 25';
51             
52         }
53         
54         //This creates a list of merchandise 
55         //to display in the search results
56         Warehouse__c[] warehouses = Database.Query(queryString);
57         for(Warehouse__c warehouse : warehouses){
58             Merchandise__c[] merch = 
59                 warehouse.getSObjects('Merchandise__r');
60                 if (merch != null) {
61                    for (Merchandise__c m : merch){ 
62                        merchandise.add(m);
63                    }
64                 }    
65         }
66         return merchandise;
67         
68    }
69    
70    //This remote action creates the invoice for the quick order
71    @RemoteAction
72    global static Line_Item__c createQuickOrder(
73        String accId, String merchandiseId){
74        Invoice__c newInvoice = new Invoice__c();
75        newInvoice.Account__c = accId;
76        insert newInvoice;
77        
78        quickOrder = new Line_Item__c();
79        Merchandise__c m = [Select Id, Name from Merchandise__c 
80            where Id=: merchandiseId limit 1];
81        quickOrder.Merchandise__c = m.Id;
82        quickOrder.Invoice__c = newInvoice.Id;
83        
84        return quickOrder;
85    }
86    
87    //This remote action creates the line item related to the 
88    //invoice for the quick order
89    @RemoteAction
90    global static Boolean insertQuickOrder(String o, String q){
91        try {
92            Integer quantity = integer.valueof(q);
93        
94        Line_Item__c order = new Line_Item__c();
95        /* The order variable being passed in as a param is being 
96        passed in the form of a JSON object. You need to use 
97        the JSON deserialize method in Apex to convert it 
98        into a SObject */
99        order = (Line_Item__c)JSON.deserialize(
100            o, Line_Item__c.class);
101        
102        order.Quantity__c = quantity;
103        insert order;
104
105    //Need to requery for the name for the post to chatter 
106    //since it wasn't explicitly specified
107    Line_Item__c li = [Select Name, Merchandise__r.Name, Id, 
108        Quantity__c, Invoice__c from Line_Item__c 
109        where Id =: order.Id];
110            
111        FeedItem post = new FeedItem();
112        post.ParentId = aId;
113        post.Body = UserInfo.getName() + ' just created a quick order';
114        post.type = 'LinkPost'; 
115        post.LinkUrl = '/' + li.Invoice__c;
116        post.Title = li.Merchandise__r.Name + ': ' + li.quantity__c;
117        insert post; 
118    } catch(System.Exception ex) {
119        system.debug(ex.getMessage());
120    }
121        return true;
122    }
123    
124    //This remote action handles deleting the invoice if 
125    //the user doesn't want to insert the line item
126    @RemoteAction
127    global static Boolean goBack(String invoiceId){
128        // Delete created invoice and return to original 
129        //search screen
130        Invoice__c cancelledInvoice = [select Id from Invoice__c 
131            where Id=: invoiceId];
132        delete cancelledInvoice;
133        
134        return true;
135    }
136    
137}