Remote Desktop fullscreen

It seems that whenever I click the Window Restore icon on a fullscreen Remote Desktop instance, a subsequent Window Maximize does not bring me back to the fullscreen. Instead I'm back in crappy maximized-with-vertical-scrollbars land.

The solution?

CTRL-ALT-BREAK

This will toggle you between fullscreen and crappy mode.

[mysql] UPDATE-JOIN

I used this query to identify duplicated records:

SELECT date, user_id, record_id
FROM records
WHERE active=1
GROUP BY date, user_id
HAVING COUNT(*)=2

Say it returns 26 records. Now I want to run a query to update these records' active column to zero. Simple, just nest the above as an outer query's IN clause, right?

UPDATE records
SET active=0
WHERE record_id IN (
  SELECT record_id
  FROM records
  WHERE active=1
  GROUP BY date, user_id
  HAVING COUNT(*)=2);

Nope. MySql has a little something to say about that plan.

You can't specify target table 'records' for update in FROM clause

Great, you can't nest a SELECT of the table you're updating. Fortunately, there is a way out, rewriting the above as an UPDATE-JOIN.

UPDATE records a 
JOIN (
  SELECT record_id
  FROM records
  WHERE active=1
  GROUP BY date, user_id
  HAVING COUNT(*)=2) b 
ON a.record_id=b.record_id
SET a.active=0;

[php] PHP_Incomplete_Class

You've saved an object instance of YourClassName into session. On a subsequent retrieval of this object from session, you discover it's now a __PHP_Incomplete_Class object!

your_object = __PHP_Incomplete_Class Object
(
  [__PHP_Incomplete_Class_Name] => YourClassName
  [id] => 123
  [name] => Fred
)

Check where you're doing the session_start. Chances are you did not include YourClassName (plus any required files of its inheritance chain, if applicable) before starting the session.

[mysql] Opening another result tab in workbench

Even when I have multiple scratch tabs open, MySql Workbench 5.3 always reuses the same "Result (1)" tab for displaying query results. But what if you want to compare the results of two queries?

Click the thumbtack icon at the top right of the Result window ("toggle pinned state of the page") after running the first. Now your next query will be forced to create a second Result tab.

[mysql] Querying column definitions

To list the columns and their definitions, simply run the query:

show columns from your_table_name

[php] Show warnings/errors

I'm always forgetting this.

error_reporting(E_ALL);
ini_set('display_errors', '1');

[js] IE yellow download bar

Say you have a "download" link. Clicking it kicks off a Javascript function that ultimately navigates the browser to your download PHP script, which serves up the file via something like:

/* download.php */
..
header('Cache-Control: public'); 
header("Content-type: application/pdf");
header('Content-Disposition: attachment; filename="' . $filename . '"');
readfile($path . $filename);

In IE, this usually pops up a "File Download" dialog asking if you want to open or save the file; pretty convenient. But something went awry somewhere. You're now getting a yellow bar warning instead. Why?

To help protect your security, Internet Explorer blocked this site from downloading files to your computer. Click here for options...

Check your Javascript. IE will allow you, the developer, to initiate a download from a click event as long as you do so within the same execution thread. Let the click thread end, though, and try to navigate to the download script from another thread, and, hello, yellow bar. In other words, look out for setTimeout.

  download_onclick:function(id) {
    window.location.href = 'download.php?id=' + id;    // good to go
  }, ..

  download_onclick:function(id) {
    setTimeout(function() {
      window.location.href = 'download.php?id=' + id;  // yellow bar
    }, 1);
  }, ..

[js] Another unexpected result

Sticking with the same theme as last post's short-circuit trickery, another Javascript operation that has an unexpected result (for me, anyway) is the assignment operation.

alert (x = 'hi');

The resultant friendly greeting demonstrates that the assignment operation not only assigns a value but actually evaluates as that value. This offers additional opportunities at simplification:

add(last_row = row);
return this.property = object.calculate(arg);
// etc.

[php] Standard get() and getr()

Would you prefer $myarray['apple'] to return null when that index doesn't exist, rather than Notice: Undefined index: apple? How about $myobj->banana to return null rather than Notice: Undefined property: stdClass::$banana? Here's a simple getter to accommodate these fervent desires.

function get($e, $id, $default = null) {
  if (is_array($e))
    return isset($e[$id]) ? $e[$id] : $default;
  else if (is_object($e))
    return isset($e->$id) ? $e->$id : $default;
  else 
    return $default;
}

$result = get($myarray, 'apple');  // instead of $myarray['apple']
$result = get($myobj, 'banana');   // instead of $myobj->banana

Another useful getter is getr, which can navigate recursively through nested object/array hierarchies (and bail out gracefully at any point it runs into an undefined.)

function getr($e, $prop, $default = null) {
  if (strpos($prop, '.') !== false) {
    $props = explode('.', $prop, 2);
    $e0 = get($e, $props[0]);
    if ($e0 === null)
      return $default;
    else 
      return getr($e0, $props[1], $default);
  } else {
    return get($e, $prop, $default);
  }
}

$myrec1->name = array('first'=>'Joe','last'=>'Blow');
$myrec2->name = null;
echo getr($myrec1, 'name.last');  // returns 'Blow'
echo getr($myrec2, 'name.last');  // returns null

[js] Forwarding arguments

If you want to call another function with all arguments supplied to this function, use the function's apply method:

pop:function() {
  this.onpop.apply(this, arguments);
  // stuff
}

[php] Calling parent's _construct()

To call the parent __construct() from an overridden constructor:

public function __construct() {
  $args = func_get_args();
  call_user_func_array(array(get_parent_class($this), '__construct'), $args);
  // do other stuff
}