Regex to validate checkbox input - php

I'm having some issues with codeigniter's validation filter when using checkboxes. I typically used the numeric filter for checkboxes, presuming it would filter for 0 or 1 but now I see there are several instances in which this fails.
Does anyone know a regex that I can put in the preg_match to validate a checkbox?
I would like this to allow for booleans and a few others 1, 0, null, true, false, empty etc...

A checkbox only returns one value. It's value (as indicated in its value= attribute) or 'true'. If the checkbox is not selected, it is not passed in the POST request. Therefore, for validation, you only need to check for 2 things:
Was it even selected in the first place?
Is its value consistent with what you expect it to be?
So:
if (isset($_POST['checkbox']) && ($_POST['checkbox'] == 'true') { //or whatever value you want
Should do the trick nicely. Unless I've misunderstood your question in which case please comment.

Checkboxes either have a value or they don't. If they have a value they're checked, if they don't then they're not checked.
A regex would be serious overkill here, you only need to check if the checkbox exists in the submitted data.
$checkBoxChecked = isset ($_POST['checkbox_name_goes_here']);

Related

form_multiselect gives only one option

Sorry, but this is kind a homework question...
I have to make a webpage with codeigniter and I have to use multiple select component.
So my code.
Part in *view.php file:
<br>Keywords:<br>
<?php echo form_multiselect('keywords', $keys); ?>
Also there is submit button, and after it pressed I take POST data. For debugging tried:
var_dump($_POST['keywords']);
This always shows, that there is only one option selected, for example, string(1) "2"
Can someone advice how should I modify my code to get all selected items.
Please try:
<?php echo form_multiselect('keywords[]', $keys); ?>
A multiselect form field must have a name with array notation.
You would expect codeignitors function to accommodate this, but it doesnt (well not when i last used CI in 2010)
From the Codeigniter documentation:
form_multiselect()
Lets you create a standard multiselect field. The first parameter will contain the name of the field, the second parameter will contain an associative array of options, and the third parameter will contain the value or values you wish to be selected. The parameter usage is identical to using form_dropdown() above, except of course that the name of the field will need to use POST array syntax, e.g. foo[].
The last sentence states you need to use POST array syntax, so the name of the select should be, in your case
name="keywords[]"

Query Based on User Input—PHP

A script I'm using takes in a string of field name/value pairs, splits them, and creates a query from them. The string is formatted like this:
var1==value1,var2==value2...
The values will be submitted by users on the frontend of the website. So, if a user selects a value for var1 and var4 but not 2 and 3 I would need the string to look like this:
var1==value1,var4==value4
Getting the user-submitted data isn't a problem. What is the best way to add in the field name and == only if the associated value is not blank?
if (isset($varname))
isset — Determine if a variable is set and is not NULL
if(empty($varname)))
empty — Determine whether a variable is empty
if(is_null($varname)))
is_null — Finds whether a variable is NULL
In other words, it only returns true when the variable is null. is_null() is the opposite of isset(), except you can use isset() on unknown variables.
You could do something like
$pairs = "var1==stuff,var3==morestuff"
if(strpos($pairs, "var2==") !== false){
$pairs .= "var2==defaultvalue";
}
And you could do that for every var# you want. This would be able to check if the
About the strpos : How do I check if a string contains a specific word in PHP?
Just whip over the submitted form fields looking for anything with a value:
foreach($_POST as $key => $value){
if($value != ''){
// do stuff
}
}
also add a check to skip the submit = submit bit :)

changing boolean values in php

I have a bunch of values from checkboxes that are boolean. Al I want to do is set them to yes if they are 1 and no if they are 0.
My code fails, looks ok to me?
$item = $form_state['values']['item1'] == 1 ? 'Yes' : 'No';
If your checkboxes have value attribute equal to 1, it should be OK:
<input ... type="checkbox" value="1" />
If you have not set these values or in all the cases you may just check, if they exists in $_GET or $_POST array (assuming $form_state is taken from there):
$item = isset($form_state['values']['item1']) ? 'Yes' : 'No';
The above example, should works for you. Keep in mind radio buttons and check boxes will not be set in $_GET or $_POST if they are not selected, at all, which also may generate Notice or Warning, if trying to access non-existing index.
In older versions of php you might need to use $_REQUEST.

Codeigniter unchecked checkbox value = blank?

I have this database where I have to capture a lot of yes/no questions, and the prefered method for the users is checkboxes. Everything is working as it should, except when it comes to retreive and show the values. Unchecked boxes return values of "0"
Is there anyway to either ignore and not display "0" in the reports OR change the default value from "0" to blank"
result = $this->input->post('checkbox',TRUE)==null ? 0 : 1
this is nothing to do with CodeIgniter. :)
How about this?
if($_POST['checkbox']==0)
$_POST['checkbox'] = '';
It is returning 0 because that is false and that's what check boxes returned when not checked. Just add an if in your CI processing method that returns whatever value you want if the checkbox value==0.
Edit: Just to clarify, this doesn't have anything to do with your CI. What I mean by it is returning 0 is that that is what the form itself is returning - that the behavior of a checkbox. To change the value will take a quick check in your CI code to change the 0 to a value you want. I assume you are accessing the value somewhere to create your email.
since the the checkbox returning null value while unchecked, you won't get a value while posting. Here is a simple quick solution for returning unchecked value from checkbox,
<input type="hidden" name="cbox" value="0" />
<input type="checkbox" name="cbox" value="1" />
if( ! $_POST['checkbox']) $_POST['checkbox'] = '';
If a checkbox is not checked, no data is sent for it. (If it is checked, the value attribute is sent). Attempting to read $_POST['checkbox'] will cause a PHP error (unless you use empty() or isset(), which are special language constructs).
this->input->post('checkbox') will return FALSE if the checkbox data is not set, i.e. if it was not checked. There's no way to change that value, I'm afraid. If you want a different value, you will need to manually compare FALSE and use a different value.
Finally, when you submit FALSE to the database using CodeIgniter's DB access API, it is converted to '0'. This would work well for a boolean column in the database. When you read out a boolean column, you'll get whatever your database's preferred code for TRUE is, regardless of what you submitted originally. (With the possible exception of sqlite, which is weakly-typed, a bit like PHP is).

Serialize checkbox array, also get checkboxes with off-value

I was wondering if this is possible.
The serialize-string will be inserted in a mySQL-database, so it would be fine if all checkboxes would be inserted and not only the ones that is ticked(on).
it's possible to make on column in the database for each of the checkboxes, and use this if/else-statement:
if(isset($_GET['checkbox'])) {
// It's checked!
}
else {
// not checked!
}
but its a bit unappropriate...
Give all the checkboxes the same name (ending in [] since this is PHP)
Give all the checkboxes different values
Have an array of all possible values in the script (you can use the same array when generating the HTML for the form!)
Loop over it and use in_array to determine if you should set it to true or false
Pass the result to your database function

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