Cocoa, Objective C MongoDB App using ObjCMongoDB.framework

Written by: Debasis Das (23-Jan-2015)

In this article we will create a simple Cocoa, Objective C App that connects to MongoDB Database through the ObjCMongoDB.framework

We will implement the following functionality in this project

• Create an Employee Collection in a Database in MongoDB
• Implement Find Functionality
• Implement Add New Employee
• Implement Modify Existing Employee & Save
• Delete Employee Record

The signature of each employee record in the MongoDB Collection will be as follows

/*
 > db.employees.findOne()
 {
	"_id" : ObjectId("54347187dbbd79a1510148b3"),
	"employee_id" : "1000",
	"first_name" : "John",
	"last_name" : "Doe",
	"email" : "JohnDoe@knowstack.com",
	"phone_number" : "408-000-0000",
	"salary" : 713077,
	"year_exp" : 30,
	"designation" : "Senior Director",
	"department" : "Finance"
 }
 */

Find Screen Using Cocoa, Objective C, MongoDB, ObjCMongoDB.framework

Add New Employee in Cocoa, Objective C, MongoDB, ObjCMongoDB.framework

Modify Existing Employee Record in Cocoa, Objective C, MongoDB, ObjCMongoDB.framework

//
//  CocoaMongoWindowController.m
//  KSCocoaMongo
//
//  Created by Debasis Das on 1/22/15.
//  Copyright (c) 2015 Knowstack. All rights reserved.
//

#import "CocoaMongoWindowController.h"
extern NSString *const HOST_WITH_PORT;
extern NSString *const COLLECTION_NAME;
@class EmployeeWindowController;

@interface CocoaMongoWindowController ()
@property (nonatomic, assign) IBOutlet NSTableView *employeeTableView;
@property (nonatomic, assign) IBOutlet NSPopUpButton *designationPopupButton;
@property (nonatomic, assign) IBOutlet NSPopUpButton *salaryQueryPopupButton;
@property (nonatomic, assign) IBOutlet NSTextField *salaryTextField;
@end

@implementation CocoaMongoWindowController

//Following is the structure of data that will be displayed in this screen
/*
 > db.employees.findOne()
 {
	"_id" : ObjectId("54347187dbbd79a1510148b3"),
	"employee_id" : "1000",
	"first_name" : "John",
	"last_name" : "Doe",
	"email" : "JohnDoe@knowstack.com",
	"phone_number" : "408-000-0000",
	"salary" : 713077,
	"year_exp" : 30,
	"designation" : "Senior Director",
	"department" : "Finance"
 }
 */

NSString *const HOST_WITH_PORT = @"127.0.0.1";
NSString *const COLLECTION_NAME = @"knowstack.employees";

- (void)windowDidLoad {
    [super windowDidLoad];
    // Implement this method to handle any initialization after your window controller's window has been loaded from its nib file.
}

-(NSString *)windowNibName
{
    return @"CocoaMongoWindow";
}


-(IBAction)find:(id)sender
{
    NSError *error = nil;
    MongoConnection *dbConn = [MongoConnection connectionForServer:HOST_WITH_PORT error:&error];
    MongoDBCollection *collection = [dbConn collectionWithName:COLLECTION_NAME];
    
    
    MongoKeyedPredicate *predicate = [MongoKeyedPredicate predicate];
    if ([self.salaryTextField intValue] !=0)
    {
        if ([[self.salaryQueryPopupButton titleOfSelectedItem] isEqualToString:@">"])
        {
            [predicate keyPath:@"salary" isGreaterThan:@([self.salaryTextField intValue])];
        }
        else if ([[self.salaryQueryPopupButton titleOfSelectedItem] isEqualToString:@"<"])
        {
            [predicate keyPath:@"salary" isLessThan:@([self.salaryTextField intValue])];
        }
        else if ([[self.salaryQueryPopupButton titleOfSelectedItem] isEqualToString:@"="])
        {
            [predicate keyPath:@"salary" matches:@([self.salaryTextField intValue])];
        }
    }
    
    NSArray *bSonArray = [collection findWithPredicate:predicate error:&error];
    NSMutableArray *mArray = [[NSMutableArray alloc] init];
    for (BSONDocument *doc in bSonArray)
    {
        [mArray addObject:[BSONDecoder decodeDictionaryWithDocument:doc]];
    }
    [self setDataArray:mArray];
    [mArray release];
    [self.employeeTableView reloadData];

}

-(IBAction)modify:(id)sender
{
    NSDictionary *employeeRecord = [self.dataArray objectAtIndex:[self.employeeTableView selectedRow]];
    [EmployeeWindowController initWithData:employeeRecord];
}

-(IBAction)delete:(id)sender
{
    NSError *error = nil;
    MongoConnection *dbConn = [MongoConnection connectionForServer:HOST_WITH_PORT error:&error];
    MongoDBCollection *collection = [dbConn collectionWithName:COLLECTION_NAME];
    MongoKeyedPredicate *predicate = [MongoKeyedPredicate predicate];
    
    
    [predicate keyPath:@"_id" matches:[[self.dataArray objectAtIndex:[self.employeeTableView selectedRow]] objectForKey:@"_id"]];
    [collection removeWithPredicate:predicate writeConcern:nil error:&error];
    [self find:self];
    if (error == NULL)
    {
        NSAlert *alert = [[NSAlert alloc] init];
        [alert setMessageText:@"Delete Confirmation"];
        [alert setInformativeText:@"The Employee has been deleted"];
        [alert runModal];
    }

}

-(IBAction)addEmployee:(id)sender
{
    EmployeeWindowController *ewc = [[EmployeeWindowController alloc] init];
    [ewc showWindow:self];
}

- (id)tableView:(NSTableView *)aTableView objectValueForTableColumn:(NSTableColumn *)aTableColumn row:(NSInteger)rowIndex
{
    NSString *aString;
    aString = [[self.dataArray objectAtIndex:rowIndex] objectForKey:[aTableColumn identifier]];
    return aString;
}

- (void)tableView:(NSTableView *)tableView setObjectValue:(id)object forTableColumn:(NSTableColumn *)tableColumn row:(NSInteger)row
{
    [[self.dataArray objectAtIndex:row] setObject:object  forKey:[tableColumn identifier]];
}

- (NSInteger)numberOfRowsInTableView:(NSTableView *)tableView
{
    long recordCount = [self.dataArray count];
    return recordCount;
}
@end

@interface EmployeeWindowController : NSWindowController
@property (assign) IBOutlet NSTextField *employeeIdTextField;
@property (assign) IBOutlet NSTextField *firstNameTextField;
@property (assign) IBOutlet NSTextField *lastNameTextField;
@property (assign) IBOutlet NSTextField *emailTextField;
@property (assign) IBOutlet NSTextField *phoneNumTextField;
@property (assign) IBOutlet NSTextField *salaryTextField;
@property (assign) IBOutlet NSTextField *yearExpTextField;
@property (assign) IBOutlet NSTextField *designationTextField;
@property (assign) IBOutlet NSTextField *departmentTextField;
@property (nonatomic, retain) NSDictionary *employeeDictionary;
@property (nonatomic, retain) NSString *recordId;

@end

@implementation EmployeeWindowController
@synthesize employeeIdTextField;

-(NSString *)windowNibName
{
    return @"EmployeeWindow";
}

+(void)initWithData:(NSDictionary *)employeeRecord
{
    EmployeeWindowController *obj = [[EmployeeWindowController alloc] init];
    [obj setEmployeeDictionary:employeeRecord];
    [obj showWindow:self];
}

-(void)awakeFromNib
{
    NSDictionary *emp = self.employeeDictionary;
    if (emp)
    {
        //Record Exists. This is a modify request
        [self.window setTitle:@"Modify Employee"];
        [self setRecordId:[emp objectForKey:@"_id"]];
        [self.employeeIdTextField setStringValue:[emp objectForKey:@"employee_id"]];
        [self.employeeIdTextField setEnabled:NO];
        [self.firstNameTextField setStringValue:[emp objectForKey:@"first_name"]];
        [self.lastNameTextField setStringValue:[emp objectForKey:@"last_name"]];
        [self.emailTextField setStringValue:[emp objectForKey:@"email"]];
        [self.phoneNumTextField setStringValue:[emp objectForKey:@"phone_number"]];
        [self.salaryTextField setStringValue:[emp objectForKey:@"salary"]];
        [self.yearExpTextField setStringValue:[emp objectForKey:@"year_exp"]];
        [self.designationTextField setStringValue:[emp objectForKey:@"designation"]];
        [self.departmentTextField setStringValue:[emp objectForKey:@"department"]];
    }
    else
    {
        //This is a new employee creation
        [self.window setTitle:@"Add New Employee"];
        NSLog(@"Do Nothing");
    }
}

-(IBAction)saveEmployee:(id)sender
{
    NSError *error = nil;
    MongoConnection *dbConn = [MongoConnection connectionForServer:HOST_WITH_PORT error:&error];
    MongoDBCollection *collection = [dbConn collectionWithName:COLLECTION_NAME];
    NSString *uniqueIdString = nil;
    
    if (self.recordId)
    {
        //Modify Request
        uniqueIdString = self.recordId;
    }
    else
    {
        NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
        [dateFormatter setDateFormat:@"MMddyyyyhhmmss"];
        uniqueIdString = [dateFormatter stringFromDate:[NSDate date]];
    }


    NSDictionary *employeeRecord = [NSDictionary dictionaryWithObjectsAndKeys:
                                    uniqueIdString,@"_id",
                                    [self.employeeIdTextField stringValue],@"employee_id",
                                    [self.firstNameTextField stringValue],@"first_name",
                                    [self.lastNameTextField stringValue],@"last_name",
                                    [self.emailTextField stringValue],@"email",
                                    [self.phoneNumTextField stringValue],@"phone_number",
                                    [self.salaryTextField stringValue],@"salary",
                                    [self.yearExpTextField stringValue],@"year_exp",
                                    [self.designationTextField stringValue],@"designation",
                                    [self.departmentTextField stringValue],@"department",
                                    nil];
    if (self.recordId)
    {
        //Update Request
        MongoKeyedPredicate *predicate = [MongoKeyedPredicate predicate];
        [predicate keyPath:@"_id" matches:self.recordId];
        
        MongoUpdateRequest *updateRequest = [MongoUpdateRequest updateRequestWithPredicate:predicate firstMatchOnly:NO];
        [updateRequest keyPath:@"first_name" setValue:[self.firstNameTextField stringValue]];
        [updateRequest keyPath:@"last_name" setValue:[self.lastNameTextField stringValue]];
        [updateRequest keyPath:@"email" setValue:[self.emailTextField stringValue]];
        [updateRequest keyPath:@"phone_number" setValue:[self.phoneNumTextField stringValue]];
        [updateRequest keyPath:@"salary" setValue:[self.salaryTextField stringValue]];
        [updateRequest keyPath:@"year_exp" setValue:[self.yearExpTextField stringValue]];
        [updateRequest keyPath:@"designation" setValue:[self.designationTextField stringValue]];
        [updateRequest keyPath:@"department" setValue:[self.departmentTextField stringValue]];
        [collection updateWithRequest:updateRequest error:&error];
        if (error == NULL)
        {
            NSAlert *alert = [[NSAlert alloc] init];
            [alert setMessageText:@"Successfully Updated"];
            [alert setInformativeText:@"The Employee changes has been successfully updated"];
            [alert runModal];
        }

    }
    else
    {
        //Insert Request
        [collection insertDictionary:employeeRecord writeConcern:nil error:&error];
        if (error == NULL)
        {
            NSAlert *alert = [[NSAlert alloc] init];
            [alert setMessageText:@"New Employee Added"];
            [alert setInformativeText:@"The Employee has been added"];
            [alert runModal];
        }

    }
}
@end

You can download the source code from here
For further read on MongoDB
For further read on ObjCMongoDB

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