PHP echo as condition inside PHP if statement - php

Question

I would like to use a PHP echo as a condition inside a PHP if statement.
The aim is to have the list of blog articles written by John Doe, displayed on his biography page.
It worked when I directly wrote the author's name in the if condition:
<!-- current page: biography page -->
<div id="list_of_articles_by_John_Doe">
<?php foreach(page('magazine')->children() as $article): ?>
<?php if($article->author() == 'John Doe'): ?>
<p><?php echo $article->title() ?></p>
<?php endif ?>
<?php endforeach ?>
</div>
But I would like to automate the process, for each writer's biography page to have their own list of articles.
I tried to have as a condition the author of the current biography page ($page):
<!-- current page: biography page -->
<div id="automatic_list_of_articles">
<?php foreach(page('magazine')->children() as $article): ?>
<?php if($article->author() == $page->author()): ?>
<p><?php echo $article->title() ?></p>
<?php endif ?>
<?php endforeach ?>
</div>
but it makes another issue: it does not work because inside the foreach statement, $page->author() (condition in the if statement) does not echo the author once, but one time for each page('magazine')->children() as $article.
The condition if($article->author() == $page->author()) does not work in this case, as $page->author() is not strictly the writer's name.
I'm wondering how to call $page->author() to echo the writer's name only once, when inside the foreach statement.

Answer 1

What could be an option is to save all author within an array
// if article->author() isn't within the array
$authors[] == $article->author();
After that you could go as the following:
<?php foreach($authors as $author){ ?>
<?php foreach(page('magazine')->children() as $article): ?>
<?php if($article->author() == $author()): ?>
<p><?php echo $article->title() ?></p>
<?php endif ?>
<?php endforeach ?>
<?php } ?>
That should work, even if you must do 2 foreachs

Answer 2

<?php if( $article->author() == $page->author() ) { ?>
<p><?php echo $article->title(); ?></p>
<?php } ?>
should work, but you can also try
<?php
if( $article->author() == $page->author() ) {
echo "\n<p>", $article->title(), "</p>\n";
}
?>
which to me looks "cleaner"; but you'd have to have a look for missing whitespaces

Answer 3

I suggest trying to set it equal too a variable and then using that variable in the if statement.
<?php foreach(page('magazine')->children() as $article): ?>
<?php $condition = $page->author()?>
<?php if($article->author() == $condition ?>'): ?>
echo "\n<p>", $article->title(), "</p>\n";
<?php endif ?>
<?php endforeach ?>
I am not sure if my syntax is correct but i think it is something along them lines.

Answer 4

You cannot use echo in condition because it is special language construct that sends given contents to the output stream and it returns no value.

Answer 5

Are you sure you shouldn't have this?
<div id="automatic_list_of_articles">
<?php $page = page('magazine'); ?>
<?php foreach($page->children() as $article): ?>
<?php if($article->author() == $page->author()): ?>
<p><?php echo $article->title() ?></p>
<?php endif ?>
<?php endforeach ?>
</div>
I have reconstructed an approximation of what looks to be your data, and you can see it working at the link below. It correctly echo's multiple article titles.
Working example:
http://ideone.com/jvLVhF
In this example you can see the PHP as above works correctly, and it is likely a data issue (ie. you should perhaps be using $page and not calling a function in the foreach statement).