Undefined index for default custom theme option

Question

I have a custom theme option that allows the changing of logos. There are 3 logo options: option1, option2, and option3.

Upon theme activation, the default "option1" logo appears, but above it I get a "Notice: Undefined index: flagship_sub_shield in...". This error goes away if I save my custom theme option page.

Is there something wrong with how I'm writing my conditional? Or is the issue probably more with the theme-options.php file?

My code in header.php is

<?php
$theme_option = flagship_sub_get_global_options();
$shield = $theme_option['flagship_sub_shield'];

if ('option2' === $shield): 

  //Image Option #2

elseif ('option3' === $shield): 
   //Image Option #3

else: 
  //Image Option #1
endif; ?>

The flagship_sub_get_global_options function is located in my theme-options.php file, in my library directory. The relevant option is:

$options[21] =
array(
    'section' => 'select_section',
    'id'      => FLAGSHIP_SUB_SHORTNAME . '_shield',
    'title'   => __( 'Shield', 'flagship_sub_textdomain' ),
    'desc'    => __( 'Which shield should appear in the header?', 'flagship_sub_textdomain' ),
    'type'    => 'select',
    'choices' => array('option1','option2','option3'),
    'std'     => 'option1',
);

Any help is appreciated!

Answer 1

You could make sure the index is defined before accessing it in header.php, and fallback gracefully:

<?php
$theme_option = flagship_sub_get_global_options();
if ( array_key_exists( 'flagship_sub_shield', $theme_option ) ) {
    $shield = $theme_option['flagship_sub_shield'];
} else {
    $shield = 'option1'; // Default value
}

if ('option2' === $shield): 

  //Image Option #2

elseif ('option3' === $shield): 
   //Image Option #3

else: 
  //Image Option #1
endif; ?>

Another possibly better option - to avoid having to include this check everytime you are getting a setting from $theme_option - would be to review your flagship_sub_get_global_options() function and make sure it returns an array that includes every setting, including default values for those settings that are not saved in the database yet.