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