This is an enhanced version of this
It’s a VERY simple php gallery. You could develop it in any direction. This one only supports jpg, but that could be augmented as well.
Here’s what it does:
To prevent a Phonegap-wrapped app from opening external links in the apps webview, use javascript to open the link in the external browser.
This works on Android (probably other platforms as well)
<a href="#" data-rel="external" target="_blank" onclick="window.open('http://www.jymden.com', '_system')">Jymden</a>Converting seconds into days, hours, minutes and seconds
int days = secondsTotal / 60 / 60 / 24;
int hours = (secondsTotal / 60 / 60) % 24;
int minutes = (secondsTotal / 60) % 60;
int seconds = secondsTotal % 60;
Add an event handler for Form Closing and use this code. This is a really simple solution.
[c language=”#”]
private void MainForm_FormClosing(object sender, FormClosingEventArgs e)
{
if (MessageBox.Show("Are you sure?", "Close application", MessageBoxButtons.YesNo) == DialogResult.Yes)
e.Cancel = false;
else
e.Cancel = true;
}
[/c]
Sometimes you need to check if a number is even or odd. A simple way to do this is using the modulus operator (the %-sign). It will calculate and return the remainder when dividing a value with another value.
So how do you use that to find out if a number is even or odd?
Short snippet:
[c language=”#”]
textBox.SelectionStart = textBox.TextLength;
textBox.ScrollToCaret();
[/c]
A simple contact form, just for reference. Will add more info later on…
[php]
<?php
if (isset($_POST[‘submit’])) {
$name = $_POST[‘name’]; //name of sender
$email = $_POST[’email’]; //e-mail of sender
$email = stripslashes($email);
$subject = $_POST[‘subject’]; //e-mail subject
$subject = str_replace(array("\r\n","\r","\n"), "", $subject); //remove any linebreaks to keep from code injections
$message = $_POST[‘message’]; // e-mail message
$message = str_replace(array("\r\n", "\r"), "\n", $message); // fix line-breaks
$message = stripslashes($message);
//headers
$headers = "From:$name<$email>\r\n";
$headers .= "Return-path: <$email>\r\n";
$headers .= "Content-type: text/plain; charset=UTF-8\r\n";
$headers .= "Content-Transfer-Encoding: 8bit\r\n";
$to = ‘myadress@mydomain.com’; //recipients e-mail adress
//validate email and name variables
if (!filter_var($email, FILTER_VALIDATE_EMAIL))
{
echo ‘not a valid e-mail adress’;
die();
}
if (preg_match(‘/[^a-z åäöÅÄÖüÜ _-]/i’, $name))
{
echo ‘not a valid name format’;
die();
}
//send the email
$send = mail($to, $subject, $message, $headers);
if ($send)
echo ’email sent’;
else
echo ‘something went wrong, email not sent’;
}
?>
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<form action="" method="post">
name:<br>
<input type="text" name="name"/>
<br>email:<br>
<input type="text" name="email"/>
<br>subject:<br>
<input type="text" name="subject"/>
<br>message:<br>
<textarea name="message"/></textarea>
<br>
<input type="submit" name="submit"/>
</form>
</body>
</html>
[/php]
Principle 1.
Always have a clear image of what you want to do BEFORE you start writing your code. Then break it down in logical instructions – making an algorithm. An algorithm is a step by step instruction on how to solve a specific problem. You might think of it as a recipe. If you want to bake bread – you don’t just start shoving any eatable stuff you find into the oven without a plan. First you decide what kind of bread you want to make, then you find out what ingredients is needed, how much and in what order they are added.
So basically – if you can’t solve the problem with logic you can’t solve it with code.
For example:
Sometimes you want to show or hide certain elements of a form, depending on the selection of a radiobutton.
I am by no means any javascript ninja, but this is one simple way I came up with:
<html>
<head>
<script type="text/javascript">
function displayElement(element) {
x = element.value;
if (x === 1) {
document.getElementById('text').style.display = '';
} else {
document.getElementById('text').style.display = 'none';
}
}
</script>
</head>
<body>
<form name="form">
<input name="choice" type="radio" value="1" onclick="DisplayElement(this)" checked/>
<input name="choice" type="radio" value="2" onclick="DisplayElement(this)"/>
<input name="text" type="text" id="text"/>
</form>
</body>
</html>
This could apply to any element. For example, you could put a whole bunch of elements in a div and the hide/show the div. Like this:
[html]
<script type=”text/javascript”>
function DisplayElement(element)
{
x = element.value;
if (x == 1) {
document.getElementById(‘container’).style.display = ”;
}
else {
document.getElementById(‘container’).style.display = ‘none’;
}
}
</script>
<form name=”form”>
<input name=”choice” type=”radio” value=”1″ onclick=”DisplayElement(this)” checked/>
<input name=”choice” type=”radio” value=”2″ onclick=”DisplayElement(this)”/>
<div id=”container”>
<input type=”checkbox”/>
<input type=”checkbox”/>
<input type=”text”/>
<input type=”text”/>
<input type=”text”/>
</div>
</form>
[/html]
Here’s another way to do it. This example takes a number as a parameter instead of using the value of the element. A bit more compact code and it might be more flexible.
[html]
<script type=”text/javascript”>
function DisplayElement(x)
{
if (x == 1) {
document.getElementById(‘text’).style.display = ”;
}
else {
document.getElementById(‘text’).style.display = ‘none’;
}
}
</script>
<form name=”form”>
<input name=”choice” type=”radio” onclick=”DisplayElement(1)” checked/>
<input name=”choice” type=”radio” onclick=”DisplayElement(2)”/>
<input name=”text” type=”text” id=”text”/>
</form>
[/html]
And here’s an even more flexible version. In this example you can pass the id of the element you want to hide as a second argument to the function. This way you can use the same function to toggle the visibility of many different elements.
[html]
<script type=”text/javascript”>
function DisplayElement(x,target)
{
if (x == 1) {
document.getElementById(target).style.display = ”;
}
else {
document.getElementById(target).style.display = ‘none’;
}
}
</script>
<form name=”form”>
<input name=”choice” type=”radio” onclick=”DisplayElement(1,’text’)” checked/>
<input name=”choice” type=”radio” onclick=”DisplayElement(2,’text’)”/>
<input name=”text” type=”text” id=”text”/>
</form>
[/html]
Here is another post, to do the same thing with a checkbox.
This is a slightly edited version of this post. Just to make it work with a checkbox instead of radio buttons.
<html>
<head>
<script type="text/javascript">
function DisplayElement(checked)
{
if (checked) {
document.getElementById('text').style.display = '';
}
else {
document.getElementById('text').style.display = 'none';
}
}
</script>
</head>
<body>
<form name="form">
<input type="checkbox" onclick="DisplayElement(this.checked)" checked/>
<input type="text" id="text"/>
</form>
</body>
</html>