Ravi Shankar – Page 36 – Tweaking Apps

Apple Mach-O-Linker Id Error – OBJC_CLASS_$_MFMailComposeViewController

March 11, 2012 By Ravi Shankar Leave a Comment

Xcode displays the Apple Mach-O undefined symbols for architecture error when the library referred in the code is not included as part of Build Phases. For example, I was instantiating MFMailComposeViewController in one of my project

MFMailComposeViewController *mc = [[MFMailComposeViewController alloc] init];

And while trying to compile the code, the build failed and displayed the following error.

Undefined symbols for architecture i386:

“_OBJC_CLASS_$_MFMailComposeViewController”, referenced from:

objc-class-ref in RootViewController.o

ld: symbol(s) not found for architecture i386

clang: error: linker command failed with exit code 1 (use -v to see invocation)

I was able to fix this issue by including the MessgeUI.framework library as part of the Build Phases.

In Xcode, navigate to Project Summary screen then to the Build Phases tab

Click the Add Items (+ sign) under Link Binary With Libraries section then select MessageUI.frameework from the list and click the Add button.

Similarly by including the relevant libraries you can resolve the obj-class-ref errors.

How to start new browser session in Internet Explorer 10

March 10, 2012 By Ravi Shankar Leave a Comment

I just came across a New Session feature on Internet Explorer 10 Consumer Preview. Generally we had to close the browser to start a new session and this would mean that all the open web pages has to be closed. But now using the New Session option, users can keep all open tabs and start a fresh session in a separate browser window.

You can start a new session by clicking the File menu then selecting New Session from the menu list.

del.icio.us Tags: Internet Explorer 10,new session,browser session

How to convert Keynote slides in to images

March 7, 2012 By Ravi Shankar 1 Comment

This article is about the feature that allows Apple Keynote users to convert the slides in to .PNG, .JPEG and .TIFF image files.

Step 1: Launch the Keynote App and open the Keynote presentation

Step 2: Click File menu and select Export from the menu list.

Step 3: Navigate to Images section and select the Slides that needs to be exported to images.

You have the option to specify all slides or range of slides. Similarly you are allowed to select the image format (JPEG, PNG, TIFF) from the drop down. After specifying the required details, click the Next button.

Step 4: Then click the Export button after providing a name and location for the images.

How to hide bookmarks bar in Safari on iPad

February 12, 2012 By Ravi Shankar 8 Comments

Safari browser on iPad, like any other PC or Mac browsers allows users to save webpage URL as bookmark. It also provides a separate Bookmarks Bar for easily accessing these saved URLs.

Screenshot with saved bookmarks

If you are not using the Bookmarks Bar on Safari then you have the option to turn off the display of Bookmarks Bar. This would give more space for the web page browsing and you can still access the saved bookmarks using the Safari browser menu items.

Hide Bookmarks Bar on Safari

Navigate to iPad home screen and tap the settings icon. Then navigate to the General section under Safari settings.

Slide the ON/OFF switch to turn off the “Always Show Bookmarks Bar”

Code Example – Check for Prime Number Objective C

February 10, 2012 By Ravi Shankar 1 Comment

This is a simple Objective C program written to check whether a number is a Prime number.

// main.m

// PrimeNumbers

// Created by Ravi Shankar on 10/02/12.

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])

{

@autoreleasepool {

int number;

BOOL isPrime=YES;

NSLog (@”Enter a number”);

scanf(“%i”,&number);

for (int i=2; i < number –1; i++)

{

if (number % i == 0)

{

isPrime = NO;

break;

}

if (isPrime)

{

NSLog (@”%i is a Prime Number”,number);

}

else

{

NSLog (@”%i is not a Prime Number”, number);

}

return 0;

}

Output (as displayed in Xcode console window)

2012-02-10 15:53:52.072 PrimeNumbers[1164:707] Enter a number

2012-02-10 15:53:58.665 PrimeNumbers[1164:707] 23 is a Prime Number

2012-02-10 15:54:41.469 PrimeNumbers[1176:707] Enter a number

2012-02-10 15:54:44.589 PrimeNumbers[1176:707] 24 is not a Prime Number

This program checks whether the number is divisible by any of the n-1 number and if divisible (% operator returns reminder as 0) then the flag is set to false otherwise it is set to true. Then based on the flag value the message is printed to the console window.

How to hide header/footer while typing in Excel 2010

February 7, 2012 By Ravi Shankar Leave a Comment

This is in response to question asked by a reader of this blog related with header and footer in Excel 2010.

how do I make the header / footer not visible on the page while typing?

When you click on the insert header and footer option in Excel 2010, excel would immediately change the view to Page Layout. Hence you would see the newly added header and footer in your worksheet.

After typing the required header and footer details and do not want to see header and footer while typing you excel sheet in the data section then you can change the view to Normal by selecting Normal under the Workbook Views section.

This would temporarily hide the inserted header and footer in the Worksheet and you can always get it back by changing the Workbook view to Page Layout.

del.icio.us Tags: Excel 2010,Header,Footer,Hide,Workbook,Worksheet,Views,Normal,Page Layout

How to disable code completion suggestion in Xcode

February 4, 2012 By Ravi Shankar Leave a Comment

Xcode is one of the powerful IDE for IOS development and by default it supports code completion suggestion. Code completion feature suggests users with possible code substitution when you start typing first few letters of code in Xcode editor.

For example, if you have UILabel reference variable and start typing “t” after the dot then the above code completion popup will be displayed. Now you can quickly pick up your desired attribute from the list.

In case if you do not prefer the code suggestion and find it more annoying then you can disable this option using the Xcode Preferences.

Click the Xcode menu and select Preferences from the menu list.

In the Preferences window, navigate to Text Editing Preferences then Code Completion under the Editing section.

Unmark the check box with caption as “Suggest completion while typing“. This should turn off the code completion feature in Xcode.

How to set Organization name for Xcode Project

February 3, 2012 By Ravi Shankar Leave a Comment

When ever a new project is created in Xcode, the projects files like header and implementation files will have auto generated comment section at the top of the file. This comment section will have information such as file name, Project name, Author and Organization name.

// ViewController.h

// Welcome

// Created by Ravi Shankar on 02/02/12.

If you have not set the organization name then the default value substituted will be _MyCompanyName_. You can set the Organization name by the following ways.

Setting Organization name under File Inspector
Updating Company name for the user in Mac Address book

File Inspector

Select the Project in the Project Navigator, then navigate to Utilities section and click the File Inspector icon. Now navigate to Project Document section and enter the company name in field with caption as Organization.

Now if you add any new file to this project then the auto generated comment will have the company name as “rshankar.com”.

Address Book

If you want to retain this organization name for all the future projects then update the company name for the user in Mac Address Book. Launch Address Book, then select the user and update the company name as shown below.

Now when ever a new project or new file is added in Xcode, the Organization name will be set the value provided for company name in address book.

// ViewController.h

// OrganizationName

// Created by Ravi Shankar on 03/02/12.

Please note that any files created before this change will not get affected and you will have to manually update company name.

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