using echo in functions

[tbobker]

ive been trying to build a content management system and have written functions for the menu, actual page content and other stuff.

i echoed out the html and content in the form of links and structure from within the function. A friend told me it is bad practice to echo anything out in a function and it should be returned?

Trouble is returning it is giving me some really weired results:

this is an example for the navigation.

first is the original:

function navigation($cid){

include("dbconnect.php");
    if(!empty($cid)){

		$sql=mysql_query("select * from Content where Cat_ID='{$cid}'",$connection);
		echo "<fieldset class=\"scat\"><legend>Sub Categories</legend>\n";
		echo "<ul class=\"nav\">\n";
		while($nav=mysql_fetch_array($sql)){
	 		echo"
	 			<li><a href=\"index.php?cid={$nav['Cat_ID']}&pid={$nav['Page_ID']}\">{$nav['menu']}</a></li>\n
	 		";
		}
		echo "</ul>\n";
		echo "</fieldset>\n";

	}elseif(empty($cid)){
		category("list","","sub_cat");
	}

}

this is the return example. It is really simplified just for example:

function main_nav(){

 $con=dbconnect();
 $sql=mysql_query("select * from content where Cat_ID='2'",$con);

 while($row=mysql_fetch_array($sql)){
   $dd= $row;
 }
 return $dd;

}

to call the function with the return i did this:

<?php
    include("functions.php");
  	$row2=main_nav();

   foreach($row2 as $row){

   echo $row['Page_ID']."<br>";
	}

?>

it is givving me some weired results - very inconsistent, or if i change it and rather put $row into $dd it only returns one value?

any pointers?

[NogDog]

You could have the function build the text to be output, then return it:

function main_nav(){
   $con=dbconnect();
   $sql=mysql_query("select * from content where Cat_ID='2'",$con);
   $dd = '';
   while($row=mysql_fetch_array($sql)){
      $dd .= $row['Page_ID']."<br>\n";
   }
   return $dd;
}

main script:

<?php
include("functions.php");
echo main_nav();
?>

[tbobker]

Damn you have saved me from going mad. I realise now why i only get one value.

.= concatenate each time the while loop goes around?!

Thanks.

Is it acceptable though / not good practice to echo in a function?

[NogDog]

For something very specific like a function that outputs page navigation, it does not bother me to echo it directly from the function (and is, in fact, what I do on my own site). For more generalized functions which might be re-used for purposes you might not have thought of when first writing it, it makes more sense to return a value which the calling script can then decide how to use.

[tbobker]

Notdog you have been very helpful but iam stuck on this very simple procedure:

I want to output the menu as an array so i can format the menu on the front page when i call it. However, because im not concatenating - im building an array it is still only out putting the first value.

But if i count the array it has six values in it?

here is my funciton:

function main_nav(){
   $con=dbconnect();
   $sql=mysql_query("select * from content",$con);
   $amount=mysql_num_rows($sql);
   $menu = array();

 while($row=mysql_fetch_array($sql)){
   for($i=0;$i<$amount;$i++){
	$menu[$i] = "<a href='index.php?pid=".$row['Page_ID']."'>".$row['Title']."\n";
   }
   }
   return $menu;
}

here is where im calling it:

   include("functions.php");
   $menu=main_nav();
   $num=count($menu);

   for($i=0;$i<$num;$i++){
   	echo $menu[$i]."<br>";
   }

[NogDog]

Looks like that for loop inside the while loop is messing things up. Also, you didn't put the closing </a> tag in. See if this works:

function main_nav(){
   $con=dbconnect();
   $sql=mysql_query("select * from content",$con);
   $amount=mysql_num_rows($sql);
   $menu = array();
   while($row=mysql_fetch_array($sql)){
      $menu[] = "<a href='index.php?pid=".$row['Page_ID']."'>".$row['Title']."</a>\n";
   }
   return $menu;
}