PHP "reserved" words that I can not use

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I'm putting together a script in PHP that what it does is generate the text that goes inside a .php file, from there I go through table and other things, but when I want to use the word, for example, $_POST[] , it generates me an error, how do I have to put $_POST[] for me to write it and show it on the screen? In what way can I "mask" this type of word so that I can see the correct word on the screen?

I pass an example: 

$script_php .= "# Generamos la sección de grabación después del POST :".$enter;


$script_php .= "if(isset($_POST['btn_grabar']))".$enter;                     


$script_php .= "{".$enter;                                                     


$script_php .= "$".$primary_key." = $SESSION['".$primary_key."']".$enter;

What I want is to visualize something like: 

if(isset($_POST['btn_grabar'])) 

    $id_hipodromo = $_SESSION['id_'];

    $id_animal=$_POST['id_animal'];
    $nombre=$_POST['nombre'];
    
asked by Walter Mesón 08.02.2018 в 16:33
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2 answers

4

You can do it in at least three ways.

Form 1: From PHP code

You write the entire code snippet in a string by storing it in a variable. But you need to make a change in the way you use the quotes: at the beginning and at the end of the string you should use single quotes ' and in the variables double quotation marks " , otherwise, the variables will be interpreted as such and it's not what's interesting here.

Then print that string using highlight_string . It is a PHP function that does the following according to the Manual:

  

Print or return html marks for a version with the syntax   highlighted the given PHP code using the colors defined in the   PHP internal syntax highlighter.

That way it will show you the indented code and (according to the Manual, with colors, according to the PHP color configuration).

This would be the code: 

$strCode='
if(isset($_POST["btn_grabar"]))    
    $id_hipodromo = $_SESSION["id_"];
    $id_animal=$_POST["id_animal"];
    $nombre=$_POST["nombre"];';
echo highlight_string($strCode);

Result on screen: 

if(isset($_POST["btn_grabar"]))
    $id_hipodromo = $_SESSION["id_"];
    $id_animal=$_POST["id_animal"];
    $nombre=$_POST["nombre"];

Form 2: Mix of PHP and HTML

You open an HTML block in your PHP and show the code. In this case, since you are in HTML, you can leave the single quotes as you originally had, since you are in HTML and the variables will not be interpreted as PHP variables. 

<?php

//Código PHP

?>
<html>
<body>    
<code>
if(isset($_POST['btn_grabar'])) <br />
    $id_hipodromo = $_SESSION['id_']; <br />
    $id_animal=$_POST['id_animal']; <br />
    $nombre=$_POST['nombre'];   <br />
</code> 
</body>
</html>

Result on screen: 

if(isset($_POST['btn_grabar'])) 
$id_hipodromo = $_SESSION['id_']; 
$id_animal=$_POST['id_animal']; 
$nombre=$_POST['nombre'];

Here the problem is that the code is not indented.

Form 3: with an external library

You can use a library to display embedded code with colors, for example Google Code Prettify . This is the way that sites that work with code examples usually use.

You just have to add the library (JS), like any other: 

<script src="https://cdn.rawgit.com/google/code-prettify/master/loader/run_prettify.js"></script>

And then open a tag like this: 

<pre class="prettyprint lang-php">

Here you indicate that you want the PHP syntax using lang-php , for the code color.

Then you write inside the code properly indented and in the end you close the label </pre> .

Let's see a test. Here we are in HTML, it can be done in PHP, adding to the chain what is necessary. Click on Ejecutar , to see the result. 

<script src="https://cdn.rawgit.com/google/code-prettify/master/loader/run_prettify.js"></script>


<pre class="prettyprint lang-php">
if(isset($_POST['btn_grabar'])) 
    $id_hipodromo = $_SESSION['id_']; 
    $id_animal=$_POST['id_animal']; 
    $nombre=$_POST['nombre'];
</pre>
    
answered by 08.02.2018 в 16:43
4

When you use strings delimited by double quotes ( " ) allowing the interpretation of variables inside, so try to convert $_POST by its value.

So the problem is not the use of "reserved words" in a string of characters, but the use of variables within them when using double quotes or heredoc .

To avoid that the variables are interpreted inside strings of characters you have two options:

Single quotes ( ' ) 

$script_php = 'if(isset($_POST[\'btn_grabar\'])) {
    $id_hipodromo = $_SESSION[\'id_\'];
    $id_animal = $_POST[\'id_animal\'];
    $nombre = $_POST[\'nombre\'];
}';

In this case you must remember to escape the single quotes with a front counterbar ( \ ).

Nowdoc 

$script_php = <<<'FINAL'
if(isset($_POST['btn_grabar'])) {
    $id_hipodromo = $_SESSION['id_'];
    $id_animal = $_POST['id_animal'];
    $nombre = $_POST['nombre'];
}
FINAL;

In this case you should not worry about escaping any character. Just do not enter the end string to your code.

Notice that heredoc is not valid because, like double quotes, it also interprets variable values.

Browser output

If you want to show that code in the browser, you should use the HTML tag <pre> or <code> and also convert entities to special characters with htmlspecialchars() : 

<pre><?= htmlspecialchars($script_php) ?></pre>

Or: 

<code style="white-space: pre;"><?= htmlspecialchars($script_php) ?></code>

By the way, you have the constant PHP_EOL that represents a line ending in your platform You should think about using it instead of your variable $enter .

    
answered by 08.02.2018 в 16:43
The cycle for does not work for me [closed] Separate a url with Javascript and save it in a variable