WordPressを使ったことがある方はお分かりになると思いますが、WordPressにはあらかじめ用意されたテーマが豊富に存在します。それを適用することで、サイトの見た目を変更することができます。 しかし、メニューの配置を変えたり、最新記事の表示部分をカスタマイズしたりといった独自のカスタマイズを施したい場合はテーマファイルの中のコードを読み解き、自分で編集していかなければなりません。 ファイルを開いた時に <?php>のようなphpの記述を目の当たりにしたとき、ファイルの中をどう変更して良いか分からずもやっとした経験をお持ちの方も多いことでしょう。 このスライドは、 「WordPressのテーマファイルをカスタマイズしたいが、phpが苦手でテーマファイルを触るのを躊躇してしまうので、phpの記述部分を詳しく理解したい」方に役にたつと思います。

1. @uemera
WordPress php

2. @uemera
uemura

7. https://paiza.io

8. <?php
$age = 21;
if( $age >= 20 ){
echo " ";
} else {
echo " ";
}
?>

9. START
END

10. <?php
$age = 21;
if( $age >= 20 ){
echo " ";
} else {
echo " ";
}
?>
<?php
$age = 21;
if( $age >= 20 ):
echo " ";
else:
echo " ";
endif;
?>
if 2

11. <?php
$age = 21
if( age >= 20 ){
echo " ";
else {
echo " ";
}
?>

12. <?php
$age = 21
if( age >= 20 ){
echo " ";
else {
echo " ";
}
?>

15. <?php
$count = 1;
while( $count <= 10 ):
echo $count . "n";
$count++;
endwhile;
?>

16. $count++
echo $count
START
END
$count = 1

17. while( $count <= 10 ):
endwhile;

18. while( 2 <= 10 ):
while( 2 ):
while( “a” ):
while( -1 ):
while( true ):
while( “false” ):

19. while( 11 <= 10 ):
while( 0 ):
while( “” ):
while( false ):

20. while( 0 <= $a && $a <= 10 ):
while( $a == 1 || $a == 2 ):
while( $a != 1 ):
while( ! $a ):

21. <?php
$count = 1;
while( $count <= 10 ):
$ans = multiply_func($count);
echo $ans . "n";
$count++;
endwhile;
function multiply_func( $num ){
$num = $num * $num;
return $num;
}
?>

28. index.php
header.php
footer.php
sidebar.php

30. <?php
get_header(); ?>
<div id="primary" class="content-area">
<main id="main" class="site-main" role="main">
<?php if ( have_posts() ) : ?>
<?php if ( is_home() && ! is_front_page() ) : ?>
<header>
<h1 class="page-title screen-reader-text"><?php single_post_title(); ?></h1>
</header>
<?php endif; ?>
<?php
while ( have_posts() ) : the_post();
get_template_part( 'template-parts/content', get_post_format() );
endwhile;
the_posts_pagination( array(
'prev_text' => __( 'Previous page', 'twentysixteen' ),
'next_text' => __( 'Next page', 'twentysixteen' ),
'before_page_number' => '<span class="meta-nav screen-reader-text">' . __( 'Page', 'twentysixteen' ) . ' </span>',
) );
else :
get_template_part( 'template-parts/content', 'none' );
endif;
?>
</main><!-- .site-main -->
</div><!-- .content-area -->
<?php get_sidebar(); ?>
<?php get_footer(); ?>

31. <?php
get_header(); ?>
<div id="primary" class="content-area">
<main id="main" class="site-main" role="main">
<?php if ( have_posts() ) : ?>
<?php if ( is_home() && ! is_front_page() ) : ?>
<header>
<h1 class="page-title screen-reader-text"><?php single_post_title(); ?></h1>
</header>
<?php endif; ?>
<?php
while ( have_posts() ) : the_post();
get_template_part( 'template-parts/content', get_post_format() );
endwhile;
the_posts_pagination( array(
'prev_text' => __( 'Previous page', 'twentysixteen' ),
'next_text' => __( 'Next page', 'twentysixteen' ),
'before_page_number' => '<span class="meta-nav screen-reader-text">' . __( 'Page', 'twentysixteen' ) . ' </span>',
) );
else :
get_template_part( 'template-parts/content', 'none' );
endif;
?>
</main><!-- .site-main -->
</div><!-- .content-area -->
<?php get_sidebar(); ?>
<?php get_footer(); ?>

32. <?php
get_header(); ?>
<div id="primary" class="content-area">
<main id="main" class="site-main" role="main">
<?php if ( have_posts() ) : ?>
<?php if ( is_home() && ! is_front_page() ) : ?>
<header>
<h1 class="page-title screen-reader-text"><?php single_post_title(); ?></h1>
</header>
<?php endif; ?>
<?php
while ( have_posts() ) : the_post();
get_template_part( 'template-parts/content', get_post_format() );
endwhile;
the_posts_pagination( array(
'prev_text' => __( 'Previous page', 'twentysixteen' ),
'next_text' => __( 'Next page', 'twentysixteen' ),
'before_page_number' => '<span class="meta-nav screen-reader-text">' . __( 'Page', 'twentysixteen' ) . ' </span>',
) );
else :
get_template_part( 'template-parts/content', 'none' );
endif;
?>
</main><!-- .site-main -->
</div><!-- .content-area -->
<?php get_sidebar(); ?>
<?php get_footer(); ?>

33. while ( have_posts() ) : the_post();
get_template_part( 'template-parts/content', get_post_format() );
endwhile;

34. while ( have_posts() ) : the_post();
get_template_part( 'template-parts/content', get_post_format() );
endwhile;

35. https://wpdocs.osdn.jp/

36. while ( have_posts() ) : the_post();
get_template_part( 'template-parts/content', get_post_format() );
endwhile;
START
END
get_template_part()
the_post()

37. get_template_part( 'template-parts/content', get_post_format() );
get_template_part( 'template-parts/content', false );

38. get_template_part( 'template-parts/content', false );

39. <article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
<header class="entry-header">
<?php if ( is_sticky() && is_home() && ! is_paged() ) : ?>
<span class="sticky-post"><?php _e( 'Featured', 'twentysixteen' ); ?></span>
<?php endif; ?>
<?php the_title( sprintf( '<h2 class="entry-title"><a href="%s" rel="bookmark">', esc_url( get_permalink() ) ), '</a></h2>' ); ?>
</header>
<?php twentysixteen_excerpt(); ?>
<?php twentysixteen_post_thumbnail(); ?>
<div class="entry-content">
<?php
the_content( sprintf(
__( 'Continue reading<span class="screen-reader-text"> "%s"</span>', 'twentysixteen' ),
get_the_title()
) );
?>
</div>
<footer class="entry-footer">
<?php twentysixteen_entry_meta(); ?>
<?php
edit_post_link(
sprintf(
__( 'Edit<span class="screen-reader-text"> "%s"</span>', 'twentysixteen' ),
get_the_title()
),
'<span class="edit-link">',
'</span>'
);
?>
</footer>
</article>

40. <article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
<header class="entry-header">
<?php if ( is_sticky() && is_home() && ! is_paged() ) : ?>
<span class="sticky-post"><?php _e( 'Featured', 'twentysixteen' ); ?></span>
<?php endif; ?>
<?php the_title( sprintf( '<h2 class="entry-title"><a href="%s" rel="bookmark">', esc_url( get_permalink() ) ), '</a></h2>' ); ?>
</header>
<?php twentysixteen_excerpt(); ?>
<?php twentysixteen_post_thumbnail(); ?>
<div class="entry-content">
<?php
the_content( sprintf(
__( 'Continue reading<span class="screen-reader-text"> "%s"</span>', 'twentysixteen' ),
get_the_title()
) );
?>
</div>
<footer class="entry-footer">
<?php twentysixteen_entry_meta(); ?>
<?php
edit_post_link(
sprintf(
__( 'Edit<span class="screen-reader-text"> "%s"</span>', 'twentysixteen' ),
get_the_title()
),
'<span class="edit-link">',
'</span>'
);
?>
</footer>
</article>

41. index.php
header.php
sidebar.php
footer.php
template-parts/content.php

42. archive.php
header.php
sidebar.php
footer.php
template-parts/content.php

45. https://wpdocs.osdn.jp/

46. print_r( $post );

47. <div id="primary" class="content-area">
<main id="main" class="site-main" role="main">
<?php if ( have_posts() ) : ?>
<?php if ( is_home() && ! is_front_page() ) : ?>
<header>
<h1 class="page-title screen-reader-text"><?php single_post_title(); ?></h1>
</header>
<?php endif; ?>
<?php
while ( have_posts() ) : the_post();
print_r( $post );
get_template_part( 'template-parts/content', get_post_format() );
endwhile;
the_posts_pagination( array(
'prev_text' => __( 'Previous page', 'twentysixteen' ),
'next_text' => __( 'Next page', 'twentysixteen' ),
'before_page_number' => '<span class="meta-nav screen-reader-text">' . __( 'Page', 'twentysixteen' ) . ' </span>',
) );
else :
get_template_part( 'template-parts/content', 'none' );
endif;
?>
</main><!-- .site-main -->
</div><!-- .content-area -->

50. <div id="primary" class="content-area">
<main id="main" class="site-main" role="main">
<?php if ( have_posts() ) : ?>
<?php if ( is_home() && ! is_front_page() ) : ?>
<header>
<h1 class="page-title screen-reader-text"><?php single_post_title(); ?></h1>
</header>
<?php endif; ?>
<?php
while ( have_posts() ) : the_post();
echo " : " . $post-> post_modified;
get_template_part( 'template-parts/content', get_post_format() );
endwhile;
the_posts_pagination( array(
'prev_text' => __( 'Previous page', 'twentysixteen' ),
'next_text' => __( 'Next page', 'twentysixteen' ),
'before_page_number' => '<span class="meta-nav screen-reader-text">' . __( 'Page', 'twentysixteen' ) . ' </span>',
) );
else :
get_template_part( 'template-parts/content', 'none' );
endif;
?>
</main><!-- .site-main -->
</div><!-- .content-area -->

53. <div id="primary" class="content-area">
<main id="main" class="site-main" role="main">
<?php if ( have_posts() ) : ?>
<?php if ( is_home() && ! is_front_page() ) : ?>
<header>
<h1 class="page-title screen-reader-text"><?php single_post_title(); ?></h1>
</header>
<?php endif; ?>
<?php
while ( have_posts() ) : the_post();
echo get_the_modified_time(‘c');
get_template_part( 'template-parts/content', get_post_format() );
endwhile;
the_posts_pagination( array(
'prev_text' => __( 'Previous page', 'twentysixteen' ),
'next_text' => __( 'Next page', 'twentysixteen' ),
'before_page_number' => '<span class="meta-nav screen-reader-text">' . __( 'Page', 'twentysixteen' ) . ' </span>',
) );
else :
get_template_part( 'template-parts/content', 'none' );
endif;
?>
</main><!-- .site-main -->
</div><!-- .content-area -->

56. @uemera uemura