Drew2

Yeah, I think it's all about constant practice - which can be tough given there are several coding languages. I've been told that young monks re-read holy texts tons of times in order to memorize them. So, perhaps taking this course once is good, but maybe not enough to reinforce everything to a master degree.

Update: actually, this code doesn't quite do it. It does something else. So, I'd say the course could use some updating.

Hello Jim, I understand your frustration. I was able to get through and understand the CRUD basics course. Yeah, 2 months is a pretty rough response time. I assume you've repeated the CRUD course a few times. If you haven't tried this already, I'd put your code in difchecker (https://www.diffchecker.com/) alongside the code you can download from the course. What I do is find a section that is probably giving trouble - it may be small. I'll copy the code I've written, and then copy the correct course code and paste it alongside one another. I tend to do this only after I've conceptually understood the concepts - but something just isn't working right in code. What usually happens is that I've missed a quotation mark or a paranthesis. Difchecker finds where the difference is. If there are no differences in your code (and this happened to me before), I find that my database connection may be to blame (the database password may be different for some users depending on what computer they use: mac or pc. my password is 'root' - others' password is just this: ''.)

I like to use dif checker: https://www.diffchecker.com/ I copy a section of code that is correct (Ben's code), and then match it against what I have written. I tend to find errors that way.

So here seems to be the stages leading up to $_SESSION['cart'] being set: First, someone clicks a link generated by m_products 'cart.php? id=' . $product['id'] Second, cart.php sees the product id in the url (generated by someone clicking the above link), and calls this function in m_cart.php to add a product: $Cart->add($_GET['id']); Third, m_cart.php starts this function: public function add($id, $num = 1) public function add($id, $num = 1) { //setup or retrieve cart $cart = array(); if(isset($_SESSION['cart'])) { $cart = $_SESSION['cart']; } //check to see if item is already in cart if (isset($cart[$id])) { //if item is in cart $cart[$id] = $cart[$id] + $num; } else { // if item is not in cart $cart[$id] = $num; } $_SESSION['cart'] = $cart; } The section of code above that I have highlighted is where $_SESSION['cart'] is initially set. I was having trouble before, because I hadn't cleared the cart before running the public function add. As a result, every time I tested this line of code, I did so assuming the $_SESSION['cart'] was empty. But when I tested the code the first conditional kept resolving to true, as if the cart had already been set (even though I thought it hadn't been). At any rate, here is how $_SESSION['cart'] is set. The first two conditionals in public function add resolve to false: $_SESSION['cart'] has not been set yet (provided no previous items were added to the cart). And, if $_SESSION['cart'] hasn't been set yet, there won't be a key of $id in the variable $cart - as $cart is just a blank array. So, that means the last piece of code will fire: a previously blank array ($cart) will be given a key ([$id]) and a value of $num (which is just 1). Then, the information in variable $cart is assigned (given) to $_SESSION['cart'].

Got it, thanks

Quick question: Why are there no periods bordering this php insertion? header("Location: $url"); I would expect it to look like this: header("Location: . $url . "); My guess, reading W3Schools and elsewhere is that both would amount to the same thing. I have to wonder though, it they amount to the same thing, why ever use the periods? -Seems like more work.

Hello you wonderful coders you. I've been staring at this line of code (line 74 highlighted below) for a while in m_template.php, and want to share what it's doing. function getAlerts() { $data = ''; foreach($this->alertTypes as $alert) { if (isset($_SESSION[$alert])) { foreach($_SESSION[$alert] as $value) { $data .= '<li class="'. $alert .'">' . $value . '</li>'; } unset($_SESSION[$alert]); } } return $data; } The unset is here so that the next time a user clicks the submit button, the $_SESSION variable will have a clean slate (at least as far as alerts are concerned). Otherwise, a user might click the submit button when they've entered valid information, and receive an error message in the members page. I just commented out the unset line and ran the code. First I entered wrong information and clicked submit. So $_SESSION now has this in it "you entered an invalid username or password." Then, I entered valid information (so now $_SESSION should also have this in it "You successfully logged in to the members page"). When I did that, I was redirected to the members page. At the top were the alerts. There was an alert saying "You successfully logged in to the members page" and then the error: "you entered an invalid username or password." Just thought others may have been confused like me about why that line of code is in there at all.

I'm on the PHP Logic with OOP section, and have what I think may be a pretty simple question. In v_login.php, where I see the login form, line 27 for example has this code: <input type="password" name="password" value="<?php echo $this->getData('input_pass'); ?>"> - This line of code takes the user input, and spits it into the form for the user to see. Then, in login.php, there is this code on line 30: $_SESSION['username'] = $Template->getData('input_user'); - this line of code adds to the $_SESSION variable. As v_login.php is included in login.php, why are there two different ways of calling the getData function? Shouldn't there just be one way to call the function, given v_login.php is included in login.php? Thanks, Andrew

Hello fellow coder fra168nk. I may have just figured out myself how include works. Imagine one document with the function of bouncing a ball. (D1) Then you have a second document with the request to actually bounce a ball (D2) For D2 to actually bounce a ball, it will need the help of D1. D1 is the tool with which D2 can bounce a ball. By writing, for example, include(D1) in D2, D2 now has access to the bouncing ball function in D1. D1 and D2 have become one document in a sense (in terms of one benefitting from the other). Although the documents are now one, in a sense, D1's location (as far as referencing CSS is concerned) is now wherever D2 is located. So, whenever a reference is made in D1 to CSS, it should be made as though D1's location is the same as D2's. It took me a while to figure that one out.

Thanks fra168nk! I came to that conclusion as well.

Hello, I'm working through the login System using OOP in Stef's course. In the file m_template.php, there is this line of code: (Line 58) function setAlert($value, $type = null) { if ($type == '') { $type = $this->alertTypes[0]; } $_SESSION[$type][] = $value; } I'm trying to see how the highlighted section of code is working. Ben explains this, but I don't quite understand yet. First of all, I want to check that my concept of the session variable $_SESSION is correct: If I unpack a hypothetical $_SESSION variable, it could look something like this: $_SESSION [ 'success' => ['you are logged in'] 'warning' =>[ ] 'error' => [] user => 'John' ] So, $_SESSION is a variable holding an array. Within that array is another array which could have a key of either success, warning, or error. $_SESSION might also have other elements in the array like user. When I write the code $_SESSION[$type][] = $value; I could think of it in this example: $_SESSION['success'][] = 'you are logged in'; This line of code means that I will be adding to the nested array with the key of 'success'. So if $_SESSION looked like this instead: $_SESSION [ 'success' => ['logging in is awesome', 'You are so bomb for logging in', 'High Five!', ] 'warning' =>[ ] 'error' => [] user => 'John' ] I would be tacking on 'you are logged in' like so: 'success' => ['logging in is awesome', 'You are so bomb for logging in', 'High Five!', 'you are logged in'] However, if I left out the brackets like so: $_SESSION['success'] = 'you are logged in'; then I would over-write the array with the key of 'success' and create this: 'success' => 'you are logged in' Am I thinking about all of this correctly? Update: Nov 11, 2020 I wonder if it is a bit unnecessary to have this line of code: $_SESSION[$type][] = $value (m_template.php, line 58) rather than this: $_SESSION[$type]= $value There doesn't seem to be any circumstance where there is more than one value per key at any given time.

I am pouring over the "simple" php login system code for Ben Falk's tutorial. There is one line of code that I cannot make sense of. After reading several sources online about prepared statements, I *only* ever see them with parameters (e.g. ?). Yet, in Ben's tutorial, there is a prepared statement without parameters in file register.php: // create select options $select = '<option value="">Select an option</option>'; $stmt = $mysqli->prepare("SELECT id, name FROM permissions"); $stmt->execute(); $stmt->bind_result($id, $name); // for more information, see http://www.php.net/manual/en/mysqli-stmt.bind-result.php while ($stmt->fetch()) { $select .= "<option value='" . $id . "'"; if ($input['type'] == $id) { $select .= "selected='selected'"; } $select .= ">" . $name . "</option>"; Why aren't there parameters (e.g. ? ?) in the prepare statement? Isn't that dangerous? Thanks! Andrew Edit: 10.23.2020 - The more I look at the code and think about it, I think it is actually harmless. The drop-down box does not allow users to enter in information, only select it. So, the information being passed to the database couldn't be (for the drop-down box) anything but what is already in the box. Yet, I still find it curious why we are using the prepare statement at all. Why not just mysqli_query(.....)?

Ok thanks

Hello, Same problem for me. I'd like to continue with the course, but can't get past this question. Any suggestions? -Andrew