Anyone comfortable using variable variables?

[clonny2]

I have a section of code i use over and over and I would like to turn it into a function passing in the args.

Thanx in advance.
I am attempting to turn this piece of code into a reuseable function.  I need to create several drop down select boxes from data pulled from postgresqldb.  Getting the data is no trouble.  I use the same piece of code over and over, just changing variable names. I would like to turn it into a function.

This is what I have so far:

function make_query ($query) {
  $result = pg_query ($conn, $query);
  $numrows = pg_num_rows ($result);
  if (!$numrows) { echo ("Can't get numrows!" exit; }
  $iLoop=0;
  
  while ( $iLoop < $numrows ) {
   $var1 = pg_fetch_result ($result,$iLoop,0);
  $option_block .=&quot;<option value='$var1'>$var1</option>&quot;;
  $display_block = &quot;<select name=\&quot;$var2\&quot;>
  $option_block </select>&quot;;
}
I need to pass in
 1: The query string
 2: var 2
 3: The variable called $display_block will need to be passed in as a variable so i can call <?php echo $display_block; ?> and it will point to the correct information.
4: also $query, $result, $numrows will need to be renamed as a variable.

I already wrote this reusing the code over and over with cut and paste. I would like to make it cleaner using a function.  

 

[sleipnir214]

I'll answer, but out of order.

3: You can do this one any one of four ways: [ul][li]have the function return the value of $display_block (

http://www.php.net/manual/en/function.return.php);

[/li][li]hand the function a variable via pass-by-reference (

http://www.php.net/manual/en/functions.arguments.php);

[/li][li]use the global keyword (

http://www.php.net/manual/en/language.variables.scope.php)

to use a copy of $display_block which is outside the function;[/li][li]or reference the $GLOBALS superglobal array (

http://www.php.net/manual/en/reserved.variables.php)

as $GLOBALS['display_block'] to instantiate the variable $display_block permanently outside the function.[/li][/ul]I would simply return the string.

2: I don't understand why you need to pass this variable in or out.

4: Those are variables.

1: You are passing in the query-string. Want the best answers? Ask the best questions:

http://www.catb.org/~esr/faqs/smart-questions.html

TANSTAAFL!

 

[clonny2]

Let me see if I can clarify,

I am creating a table that has several db-driven drop down select boxes and each one is created the same way with a slight query string diff. I changed the variable names slightly to match each drop down, however this has produced alot of cut and paste with slight changes. I would like to make it a reusable function so that i can just call the function and pass the parameters so the code can be condensed and cleaned up.
He is some of the old code that I want to use this function:

//Auto-Auto=100F
$aa_query = (&quot;SELECT * FROM modes where speed !='auto'&quot;
$aa_result = @pg_query ($conn,$aa_query);
if (!$aa_result) { echo (&quot;Can't make query&quot; exit; }

$aa_numrows = @pg_num_rows ($aa_result) ;

if (!$aa_numrows) { echo (&quot;Can't get numrows&quot; exit; }

$iLoop =0;

while ($iLoop < $aa_numrows) {
$aa_types = pg_fetch_result ($aa_result,$iLoop,0);

$aa_option_block .= &quot;<option value='$aa_types'>$aa_types</option>&quot;

$iLoop ++:

$aa_display_block =&quot; <select name=\&quot;eaa\&quot;>
$aa_option_block </select>&quot;;


I use this over and over and over. I am trying to turn that into a function that I can 1: pass the query string 2: return the display_block.

The HTML is a table
<FORM>
<TABLE>
<TR>
<TD><?php echo $display_block; ?> </TD>
</TR>
</TABLE>
</FORM>
But there are lots more cells, etc.. But that is the jist of it. Since it is a form, each cell needs to have a different name for the select statement becaue they are indepdant form items.

 

[sleipnir214]

I would create a function which accepts as its input parameter the SQL query string you want to use, which then queries the database and outputs the HTML necessary to create the <option>...</option> tags of your <SELECT> element.

You could then call it as:

print '<SELECT name=&quot;foo&quot;>';

output_options (&quot;SELECT * FROM modes where speed !='auto'&quot;

print '</SELECT>'; Want the best answers? Ask the best questions:

http://www.catb.org/~esr/faqs/smart-questions.html

TANSTAAFL!

 

[skiflyer]

And if you want to wrap it all into one, just do an output_select(&quot;foo&quot;, &quot;SELECT....&quot;

then output_select looks something like
function output_select($var_name, $query_string) {
echo '<SELECT name=&quot;'.$var_name.'&quot;>';
....
echo '</SELECT>';
}

Just my way way of doing it...

-Rob

 

[AceStone]

What I've been doing with my site involves using two files, one is a &quot;include&quot; file which contains all the class and/or functions that are used on a regular basis. That way, you can call that same function from any page on your site But, as far as creating a function, from what I've seen on your post, you've already got it set up as a function. Try putting it in &quot;../include/pages.inc&quot; then at the top of your script
include(&quot;../include/pages.inc&quot;
In that include file, create a class.....
class pages
{
Your_Function($param)
{
various code goes here;
return $result;
}
}
In the page that you are wanting to use this on, before you can use it.......
$welcome=new Pages();
Then, when you want to call that function....
$rs=$welcome->Your_Function($param);
The nice thing about using classes is that you can also set up global variables which can be accessed from any page as well
I realize this is a bit sketchy, but hope it helps