PHP Preselect check boxes from a String - php

Question

I have a string $eventdays which holds information regarding which days are selected.
The format of the data is:
Monday = Mo
Tuesday = Tu
Wedneday = We
Thursday = Th
Friday = Fr
Saturday = Sa
Sunday = Su
Mo,Tu,We,Th,Fr,Sa,Su
So if for example Tuesday and Friday were selected, the string would be:
Tu,Fr
If Monday, Wednesday, and Saturday were selected it would be:
Mo,We,Sa
Note: Any combination of days can be selected.
I was wondering how to get this information, and preselect checkboxes. The checkboxes are:
<input type="checkbox" name="days[]" value="Mo" />Monday<br />
<input type="checkbox" name="days[]" value="Tu" />Tuesday<br />
<input type="checkbox" name="days[]" value="We" />Wednesday<br />
<input type="checkbox" name="days[]" value="Th" />Thursday<br />
<input type="checkbox" name="days[]" value="Fr" />Friday<br />
<input type="checkbox" name="days[]" value="Sa" />Saturday<br />
<input type="checkbox" name="days[]" value="Su" />Sunday<br />
I know how to preselect a checkbox (checked = "yes"), but my question is how can I parse the string and then select the correct checkboxes from that information?

Answer 1

You can use strpos and dynamically generate your checkboxes.
$eventdays = "Tu,Fr"; // Selected days
$days = array( "Monday" => "Mo",
"Tuesday" => "Tu",
"Wedneday" => "We",
"Thursday" => "Th",
"Friday" => "Fr",
"Saturday" => "Sa",
"Sunday" => "Su"
);
foreach ($days AS $day => $shortDay) {
// Is there an event on this day?
$checked = strpos($eventdays, $shortDay) !== FALSE ? "checked='checked'" : "";
// Generate checkbox HTML
echo "<input type='checkbox' name='days[]' value='{$shortDay}' {$checked} />{$day}<br />";
}
Output
<input type='checkbox' name='days[]' value='Mo' />Monday<br />
<input type='checkbox' name='days[]' value='Tu' checked='checked'/>Tuesday<br />
<input type='checkbox' name='days[]' value='We' />Wedneday<br />
<input type='checkbox' name='days[]' value='Th' />Thursday<br />
<input type='checkbox' name='days[]' value='Fr' checked='checked'/>Friday<br />
<input type='checkbox' name='days[]' value='Sa' />Saturday<br />
<input type='checkbox' name='days[]' value='Su' />Sunday<br />

Answer 2

Assuming your input is a string with line-breaks... First process your data into an keyed array to make life easier... I've used regexes to make it more robust against formatting changes.
$eventdays="Monday = Mo
Tuesday = Tu
Wedneday = We
Thursday = Th
Friday = Fr
Saturday = Sa
Sunday = Su";
$lines = explode("\n", $eventdays);
$data = array();
foreach ($lines as $line) {
if (preg_match("/(\w+)\s*=\s*(\w+)/", $line, $match)) {
$data[] = array('value'=>$match[2], 'label' => $match[1]);
}
}
Now just iterate over the structure printing out the keys / labels. Use the in_array function to check if the current one should be selected. Also I used checked="checked" which is the standards-compliant way of selecting checkboxes... See this question.
$selected_test="Mo,We,Sa";
$select=explode(",", $selected_test);
foreach ($data as $datum) {
$checked="";
if (in_array($datum['value'], $select)) {
$checked = " checked=\"checked\"";
}
echo <<< EOF
<input type="checkbox" name="days[]" value="{$datum['value']}"$checked/>{$datum['label']}<br />\n
EOF;
}
Output
<input type="checkbox" name="days[]" value="Mo" checked="checked"/>Monday<br />
<input type="checkbox" name="days[]" value="Tu"/>Tuesday<br />
<input type="checkbox" name="days[]" value="We" checked="checked"/>Wedneday<br />
<input type="checkbox" name="days[]" value="Th"/>Thursday<br />
<input type="checkbox" name="days[]" value="Fr"/>Friday<br />
<input type="checkbox" name="days[]" value="Sa" checked="checked"/>Saturday<br />
<input type="checkbox" name="days[]" value="Su"/>Sunday<br />

Answer 3

use explode(), it returns an array
$days = "mon,tu";
$needstobeselected= explode(",", $days);
then you have an array with the days that has to be checked. you can then make a loop on the array and write your logic.
i guess crappy method, but build a $checkeddays array, like:
[0] => 'checked',
[1] => ' ',
and so on, then use it :
echo '<input type="checkbox" name="days[]" value="Mo" '.$checkeddays[0].'/>Monday<br />'
the main part is explode.