displaying php in an echo nested in html-CodePudding

I'm trying to echo a piece of text with PHP nested in it, anyone know how? I've tried it like this:

function update_category(){

    global $connection;

    if (isset($_GET['edit'])) {
        $edit_cat_key = $_GET['edit'];

        $query = "SELECT * FROM categories WHERE cat_id = {$edit_cat_key }";
        $edit_cat_query = mysqli_query($connection, $query);

        echo    '<form action="categories.php" method="post">
                    <div >
                        <label for="new-cat-title">New name of category</label>
                            <input value="<?php if(isset($cat_title)){echo $cat_title;} ?>" type="text"  name="new-cat-title">
                    </div>
                    <div >
                        <input  type="submit" name="submit" value="Rename Category">
                    </div>
                </form>';

            
        while($row = mysqli_fetch_assoc($edit_cat_query)) {
            $cat_title = $row['cat_title'];
            $cat_id = $row['cat_id'];
        }
    }

}

It prints: <?php if(isset($cat_title)){echo $cat_title;} ?>

I've tried it like this:

<input value="' . <?php if(isset($cat_title)){echo $cat_title;} ?> . '" type="text"  name="new-cat-title">

CodePudding user response：

I'd do it like this (showing only the echo part inside the php code):

echo '<form action="categories.php" method="post">
                <div >
                    <label for="new-cat-title">New name of category</label><input value="';

if(isset($cat_title)){echo $cat_title;};
echo '" type="text"  name="new-cat-title"></div>
                <div >
                    <input  type="submit" name="submit" value="Rename Category">
                </div>
</form>';

This echoes the two strings (in single quotes) and in between them the variable depending on the condition, keeping the double-quote pairs of the attribute values intact.

CodePudding user response：

Echo is a php statement. You use it to display an output, as a string. What you need is, replacing echo ' with ?> and </form>'; with </form><?php. These closing(?>) and opening(<?php) tags let you decide which part of your document should be processed as PHP. So PHP will ignore the rest of the document.

CodePudding user response：

Based on Johannes' answer I managed to figure out an answer. I need to close the PHP tags and instead of echoing the wished result, put it in the while loop.

Like this:

    function update_category(){
    
        global $connection;
    
        if (isset($_GET['edit'])) {
            $edit_cat_key = $_GET['edit'];
    
            $query = "SELECT * FROM categories WHERE cat_id = {$edit_cat_key }";
            $edit_cat_query = mysqli_query($connection, $query);
        
            while($row = mysqli_fetch_assoc($edit_cat_query)) {
                $cat_title = $row['cat_title'];
                $cat_id = $row['cat_id'];
    
                ?>
                    <input value="<?php echo $cat_title; ?>" type="text"  name="cat_title">
                <?php
        }
    }

}