Re: [PHP] parsing select multiple="multiple"

On Tue, Feb 19, 2013 at 1:02 PM, John Taylor-Johnston
<[email protected]> wrote:
>
> tamouse mailing lists wrote:
>>>
>>> >I hate arrays. :D
>>
>> Here's a small snippet showing how it works, I hope:
>>
>> foreach ($DPRpriority as $item => $value) {
>>    echo "<li> ".$item.": ".$value['name']." selected:
>> ".$value['selected']." </li>\n";
>> }
>>
> Question 1: when did we have to add [] to a <input> name to turn it into an
> array?
>
> <input type="checkbox" name="DPRlocationdetails[]" value="Unknown">
>
> According to phpinfo() it still comes out as $_POST['DPRlocationdetails']
> without [].
>
> Are the [] necessary?

[] are necessary when you want to return multiple values for a form
field, or collection of form fields such as checkbox. AFAIK, this has
always been the case with PHP. See
https://gist.github.com/tamouse/5002728

> ----------------------------------------------
> Question 2:
> I was looking at some code in the Manual, where someone used isset and
> is_array.
>
> How necessary is if(isset($_POST['DPRlocationdetails']))
>
> and then to use: if(is_array($_POST['DPRlocationdetails']))
>
> That seems like over kill?

It's more defensive, in the case where someone may be by-passing your
form to send things in.

> ----------------------------------------------
> Question 3:
>
> My code works, perfectly.

Then there must be no questions. :)

> In this case, I decided to attack some check-boxes
> first. The resulting function will work for <select multiple> too..
>
> Does anyone see me doing something wrong in my code below?
>
> My questions are:
>
> Is this the only way to pass "Unknown", "Family Home" or "Apartment" into
> the function?
>
> Is this correct?
>
> ---- if ($_POST['DPRlocationdetails'] == "Unknown")
>
> Somebody once told me I had to do it this way?
>
> ---- if ("Unknown" == $_POST['DPRlocationdetails'])

In this scenario, these are equivalent. There is no preference of one
over the other.

I *have* heard claims that something like this is preferrable, though:

if (FALSE === $variable)

But I think that may have been due to some misunderstanding of
precedences in the following sort of scenario:

if (FALSE === ($result = some_function())

where if done this way:

if ($result = some_function() === FALSE)

was giving them bad results.

> John
>
> --------------------snip---------------------------
>
> <form action="foo.php" id="DPRform" method="post"><input value="Update"
> type="submit">
> <input type="checkbox" name="DPRlocationdetails[]" value="Unknown" <?php
> filter_value($_POST['DPRlocationdetails'],"Unknown"); ?>> Unknown
> <input type="checkbox" name="DPRlocationdetails[]" value="Family Home" <?php
> filter_value($_POST['DPRlocationdetails'],"Family Home"); ?>> Family Home
> <input type="checkbox" name="DPRlocationdetails[]" value="Apartment" <?php
> filter_value($_POST['DPRlocationdetails'],"Apartment"); ?>> Apartment
> </form>
>
> <?php
> function filter_value($tofilter,$tofind) {
> foreach($tofilter as $value){
>     if ($value == $tofind) echo "checked";
>     }
> }
> ?>
>
>