Archive for June, 2009

Easier PHP forms, part 2

Tuesday, June 30th, 2009

In part 1 I showed you my method for simplifying form building and maintenance.  Now I’d like to show you a few of the things that can be simplified by using this system.  Included are:

  • prices
  • passwords
  • emails
  • textareas
  • selects
  • yes/no (booleans)
  • files
  • hiddens
  • cancel buttons
  • submit buttons
  • “are you sure you want to do that?” submit buttons
  • addresses

I use this code for 95% of the forms I build and then modify the CSS to get the effects a customer wants.

In part 3 I’ll show you how to use jQuery to automatically validate user data.

//------------------------------------------------------------------------------
function create_form_price($name,$value=null,$label=null,$hint=null) {
  return create_form_row("\$<input type='text' name='$name' value='".htmlspecialchars($value,ENT_QUOTES)."'>",$label,$name,$hint);
}
 
//------------------------------------------------------------------------------
function create_form_password($name,$value=null,$label=null,$hint=null) {
  return create_form_row("<input type='password' name='$name' value='".htmlspecialchars($value,ENT_QUOTES)."'>",$label,$name,$hint);
}
 
//------------------------------------------------------------------------------
function create_form_password_confirm($name,$value=null,$label=null,$hint=null) {
  add_form_test_password_confirm("pass",$label);  // we'll cover this in part 3
 
  return create_form_row("<input type='password' name='$name' value='".htmlspecialchars($value,ENT_QUOTES)."'>",$label,$name,"").
  create_form_row("<input type='password' name='{$name}_confirm' value=''>"," ",$name."_confirm",$hint);
}
 
//------------------------------------------------------------------------------
function create_form_email($name,$value=null,$label=null,$hint=null) {
 // @TODO: add email validation.
 $test="    regex_{$name}=/^[a-zA-Z0-9_-]+(\.[a-zA-Z0-9_-]+)*@[a-zA-Z0-9_-]+(\.[a-zA-Z0-9_-]+)*(\.[a-zA-Z]{2,4})$/\n"
 ."    compare_to=f.{$name}.value.replace(/^\s+|\s+$/g,'');\n"
 ."    if(compare_to!='' && !compare_to.match(regex_{$name})) {\n"
 .add_form_error($name,"$label does not appear to be a valid email.\n")
 ."    }\n";
 add_form_test($test,$name);
 
 return create_form_row("<input type='text' name='$name' value='".htmlspecialchars($value,ENT_QUOTES)."'>",$label,$name,$hint);
}
 
//------------------------------------------------------------------------------
function create_form_textarea($name,$value=null,$label=null,$hint=null) {
 return create_form_row("<textarea name='$name' rows='10' cols='80'>".htmlspecialchars($value,ENT_QUOTES)."</textarea>",$label,$name,$hint);
}
 
//------------------------------------------------------------------------------
function create_form_select_internal($name,$options,$value=null,$multiple=0,$extra='') {
 $sel="<select id='$name' name='$name' $extra";
 if($multiple>0) {
 $sel.=" multiple='yes' size='$multiple'";
 }
 $sel.=">\n";
 if(is_array($options)) {
 foreach($options as $k=>$v) {
 $k=htmlspecialchars($k,ENT_QUOTES);
 $v=htmlspecialchars($v,ENT_QUOTES);
 $sel.="  <option value='$k'>$v</option>\n";
 }
 }
 $sel.="</select>";
 $v=isset($value)?htmlspecialchars($value,ENT_QUOTES):"";
 return str_replace("value='$v'","value='$v' selected",$sel);
}
 
//------------------------------------------------------------------------------
function create_form_select($name,$options,$value=null,$label=null,$hint=null,$multiple=0,$extra='') {
 $sel=create_form_select_internal($name,$options,$value,$multiple,$extra);
 return create_form_row($sel,$label,$name,$hint);
}
 
//------------------------------------------------------------------------------
function create_form_bool($name,$value=null,$label=null,$hint=null,$extra='') {
 $sel="<select name='$name' $extra>\n";
 $sel.="  <option value='yes'>"._t("Yes")."</option>\n";
 $sel.="  <option value='no'>"._t("No")."</option>\n";
 $sel.="</select>";
 $v=isset($value)?htmlspecialchars($value,ENT_QUOTES):"";
 $sel=str_replace("value='$v'","value='$v' selected",$sel);
 return create_form_row($sel,$label,$name,$hint);
}
 
//------------------------------------------------------------------------------
function create_form_file($name,$label='',$hint='') {
 $inner="<input name='$name' type='file'>";
 
 return create_form_row($inner,$label,$name,$hint);
}
 
//------------------------------------------------------------------------------
function create_form_address($name,$value=null,$label=null,$hint=null) {
 if(!isset($value['address1'])) $value['address1']="";
 if(!isset($value['address2'])) $value['address2']="";
 if(!isset($value['city'])) $value['city']="";
 if(!isset($value['region'])) $value['region']="";
 if(!isset($value['country'])) $value['country']="";
 if(!isset($value['postalcode'])) $value['postalcode']="";
 
 $str =create_form_text($name."_address1",$value['address1'],"Street");
 $str.=create_form_text($name."_address2",$value['address2'],"");
 $str.=create_form_text($name."_city",$value['city'],"City");
 $str.=create_form_text($name."_region",$value['region'],"State/Province");
 $str.=create_form_text($name."_country",$value['country'],"Country");
 $str.=create_form_text($name."_postalcode",$value['postalcode'],"Postal Code");
 
 return create_form_row($str,$label,null,null);
}
 
//------------------------------------------------------------------------------
function create_form_hidden($name,$value=null) {
 return "  <input type='hidden' id='$name' name='$name' value='".htmlspecialchars($value,ENT_QUOTES)."'>\n";
}
 
//------------------------------------------------------------------------------
function create_form_submit($name,$value,$extra='') {
 global $last_form_name;  // we'll cover this is in part 3
 
 return "  <input type='submit' name='$name' value='".htmlspecialchars($value,ENT_QUOTES)."' onclick='javascript:return validate_$last_form_name(this.form);' $extra>\n";
}
 
//------------------------------------------------------------------------------
function create_form_cancel($name,$value,$redirect) {
 return "  <input type='button' name='$name' value='".htmlspecialchars($value,ENT_QUOTES)."' onclick='javascript:window.location=\"".htmlspecialchars($redirect,ENT_QUOTES)."\";'>\n";
}
 
//------------------------------------------------------------------------------
function create_form_submit_confirm($name,$value,$confirm="Are you sure?",$validate=0) {
 global $last_form_name;  // we'll cover this is in part 3
 
 $str="  <input type='submit' name='$name' value='".htmlspecialchars($value,ENT_QUOTES)."' onclick='javascript:return (confirm(\"".str_replace(array("'","\n"),array("\'","\\n"),$confirm)."\")";
 if($validate!=0) {
 $str.=" & validate_$last_form_name(this.form)";
 }
 $str.=");'>\n";
 return $str;
}
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Easier PHP forms, part 1

Monday, June 29th, 2009

Building and maintaining forms in PHP is one of the most time-consuming parts of the job.  Put another way, it’s one of the biggest bottlenecks for fast prototyping and development.  Getting rid of bottlenecks speeds up work and increases overall joy.  So how do we do this?

The first thing I did was look at all the forms I had been writing.  In general they all follow a pattern:

<DOCTYPE ...>
<html ...>
<head>
  ...
  // javascript tests to make sure user fills form correctly
</head>
<body>
...
<form name='blah' action='#' method='post'>
...

  <div class='form_item'>
    <label for='ABC'>A human-readable name for the input</label>
    <div class='input_item'>
      <input name='ABC'>  <?/* or select/textarea/etc */?>
      <div class='help'>Some explanation text here.</div>
    </div>
    <div class='clear'></div>
  </div>
...
</form>
...
</body>
</html>

It seemed that cutting and pasting this was rife with errors.  Even worse is trying to change the layout of the page – a major (non-CSS) alteration could really ruin my day!  I had to come up with somethin better.

function create_form_row($input,$label_name=null,$label_for=null,$hint=null) {
                         $str ="  <div class='form_item'>\n";
  if(isset($label_name)) $str.="    <label for='$label_for'>$label_name</label>\n";
                         $str.= "    <div class='input_item'>\n";
                         $str.= "      $input\n";
  if(isset($hint))       $str.= "      <div class='help'>$hint</div>\n";
                         $str.= "    </div>\n";
                         $str.= "    <div class='clear'></div>\n";
                         $str.= "  </div>\n";
  return $str;
}

function create_form_start($name,$classname='form',$action='',$method='post',$target='') {
  return "<form enctype='multipart/form-data' id='$name' name='$name' class='$classname' action='$action' method='$method'>\n";
}

function create_form_end() {
  echo '</form>\n';
}

At first this might seem like a lot of work for not much gain.  Think of this as the center of the onion.  If we build layers on top of it we start to see some big big benefits.

function create_form_check_inner($name,$value=null,$checked=false) {
  return "<input type='checkbox' id='$name' name='$name' value='".htmlspecialchars($value,ENT_QUOTES)."'".($checked?" checked":"").">";
}

//------------------------------------------------------------------------------
function create_form_check($name,$value=null,$label=null,$hint=null,$checked=false) {
  return create_form_row($label,create_form_check_inner($name,$value,$checked),$name,$hint);
}

//------------------------------------------------------------------------------
function create_form_text_inner($name,$value=null,$extra='') {
  return "<input type='text' id='$name' name='$name' value='".htmlspecialchars($value,ENT_QUOTES)."' $extra>";
}

//------------------------------------------------------------------------------
function create_form_text($name,$value=null,$label=null,$hint=null,$extra='') {
  return create_form_row(create_form_text_inner($name,$value,$extra),$label,$name,$hint);
}

So now when I want to create a new form all I do is

echo create_form_start('form1');
echo create_form_text('user_name','','User Name','what is your name?');
echo create_form_check('love_this','yes','Love','Do you love this new form system?',true);
echo create_form_end();

In Part II I’ll show you how to use create_form_ elements for passwords, selects, textareas, and more.

In Part III I’ll show you how you can use this system and jQuery to add checks that make sure users put in valid emails, required fields, and so on.

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The Difference

Tuesday, June 23rd, 2009
The difference between yawning and rocking out.

The difference

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Site Moving

Monday, June 22nd, 2009

This site is going to move to it’s new server some time in the next 24h.  I only hope it goes without a hitch.  Finally I will be able to turn my machine(s) off at night!  Yay!

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Updating PHP cookies without breaking the experience

Friday, June 19th, 2009

PHP cookies are a great idea for storing data temporarily.  Sure, they have their security problems but (arguably) they do more good than bad.  The trickiest part about cookies is when you update your PHP and it forces you to change the contents of your cookies.  You don’t want your faithful site visitors to see an error message!  Consider the following naive implementation:

function save() {
  setcookie("username","foo",60*60*24*30);
}
 
function load() {
  return isset($_COOKIE["username"])?$_COOKIE["username"]:'';
}

It doesn’t take a lot of imagination to see how this could break.  Let’s start by making it easier to store lots of info in a single cookie.

function save() {
  $data=array('username'=&gt;'foo', 'something else'=&gt;'bar');
  $str=serialize($data);
  setcookie("userdata",$str,60*60*24*30);
}
 
function load() {
  $data=array('username'=&gt;'','something else'=&gt;'');
  if(isset($_COOKIE['userdata'])) {
     $data=unserialize($_COOKIE['userdata']);
  }
  return $data;
}

Ok, but what about if we need to add more data to our cookies later?  Everyone with an old cookie will be missing parts of $data and we’ll have to catch that.

function save() {
  $data=array('version'='1.0', 'username'=&gt;'foo', 'something else'=&gt;'bar');
  $str=serialize($data);
  setcookie("userdata",$str,60*60*24*30);
}
 
function load() {
  $data=array('username'=&gt;'','something else'=&gt;'');
  $old=false;
  if(isset($_COOKIE['userdata'])) {
    try {
      $data=unserialize($_COOKIE['userdata']);
    }
    catch(Exception $e) {
      $old=true;  // this version is so old &amp; busted we can't read it at all.
    }
    if(!$old) {
      // Use the $data['version'] to help us figure out what pieces of $data need to be filled in.
    }
  }
  return $data;
}

And… voila!

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Cold Souls & Walking Corpses

Friday, June 19th, 2009

I love a movie that dares to be different.

Sometimes, though, I just love to see zombies.

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Hello world!

Thursday, June 18th, 2009

This is the first post on my new site.  Whee.  I will attempt to update this every day with *something*, even if it’s garbage about how much I squatted at the gym or something funny I saw on the interwebitubes.

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