code-boxx/0-PHP-PASS-VAR-JS.MD

## 0-PHP-PASS-VAR-JS.MD

      
    Raw
  

              0-PHP-PASS-VAR-JS.MD
            
          
    PASS PHP VARIABLES TO JAVASCRIPT

https://code-boxx.com/pass-php-variables-arrays-to-javascript/
LICENSE

Copyright by Code Boxx
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

  
## 1a-echo-js.php
<!-- (A) PHP VARIABLE -->
<?php $phpvar = "Foo"; ?>

<!-- (B) USE PHP TO ECHO JAVASCRIPT CODE -->
<script>
<?php echo "var jsvar = '$phpvar';"; ?>
console.log(jsvar);
</script>

## 1b-short-tag.php
<!-- (A) PHP VARIABLE -->
<?php $phpvar = "Foo"; ?>

<!-- (B) PHP SHORT ECHO TAG TO ECHO VARIABLE -->
<script>
var jsvar = "<?=$phpvar?>";
console.log(jsvar);
</script>

## 2-input.php
<!DOCTYPE html>
<html>
  <head>
    <title>PHP Var Into Form</title>
  </head>
  <body>
    <!-- (A) PHP VARIABLE -->
    <?php $phpvar = "Foo"; ?>

    <!-- (B) INSERT INTO HTML FORM -->
    <form onsubmit="return demo()">
      <input type="text" id="myTxt" value="<?=$phpvar?>">
      <input type="submit" value="Go">
    </form>

    <!-- (C) JS GET FIELD VALUE -->
    <script>
    function demo () {
      // (C1) GET FIELD VALUE
      var jsvar = document.getElementById("myTxt").value;
      console.log(jsvar);

      // (C2) PREVENT FORM SUBMIT
      return false;
    }
    </script>
  </body>
</html>

## 3-json.php
<?php
// (A) PHP CONVERT ARRAY TO STRING
$phpvar = json_encode(["Apple", "Banana", "Cherry"]);
?>

<!-- (B) JAVASCRIPT CONVERT STRING TO ARRAY -->
<script>
var jsvar = JSON.parse('<?=$phpvar?>');
console.log(jsvar);
</script>

## 4a-ajax.html
<!DOCTYPE html>
<html>
  <head>
    <title>Simple AJAX</title>
  </head>
  <body>
    <!-- (A) AJAX FETCH DATA FROM SERVER -->
    <script>
    function doAJAX () {
      fetch("4b-ajax.php")
      .then(res => res.text())
      .then(data => console.log(data));
    }
    </script>

    <!-- (B) GO! -->
    <input type="button" value="AJAX Fetch" onclick="doAJAX()">
  </body>
</html>

## 4b-ajax.php
<?php
$phpvar = "Foo";
echo $phpvar;

## 5a-ajax-json.html
<!DOCTYPE html>
<html>
  <head>
    <title>Simple AJAX JSON</title>
  </head>
  <body>
    <!-- (A) AJAX FETCH DATA FROM SERVER -->
    <script>
    function doAJAX () {
      fetch("5b-ajax.php")
      .then(res => res.json())
      .then(data => console.log(data));
    }
    </script>

    <!-- (B) GO! -->
    <input type="button" value="AJAX Fetch" onclick="doAJAX()">
  </body>
</html>

## 5b-ajax.php
<?php
echo json_encode(["Apple", "Banana", "Cherry"]);
	<!-- (A) PHP VARIABLE -->
	<?php $phpvar = "Foo"; ?>

	<!-- (B) USE PHP TO ECHO JAVASCRIPT CODE -->
	<script>
	<?php echo "var jsvar = '$phpvar';"; ?>
	console.log(jsvar);
	</script>
	<!-- (A) PHP VARIABLE -->
	<?php $phpvar = "Foo"; ?>

	<!-- (B) PHP SHORT ECHO TAG TO ECHO VARIABLE -->
	<script>
	var jsvar = "<?=$phpvar?>";
	console.log(jsvar);
	</script>
	<!DOCTYPE html>
	<html>
	<head>
	<title>PHP Var Into Form</title>
	</head>
	<body>
	<!-- (A) PHP VARIABLE -->
	<?php $phpvar = "Foo"; ?>

	<!-- (B) INSERT INTO HTML FORM -->
	<form onsubmit="return demo()">
	<input type="text" id="myTxt" value="<?=$phpvar?>">
	<input type="submit" value="Go">
	</form>

	<!-- (C) JS GET FIELD VALUE -->
	<script>
	function demo () {
	// (C1) GET FIELD VALUE
	var jsvar = document.getElementById("myTxt").value;
	console.log(jsvar);

	// (C2) PREVENT FORM SUBMIT
	return false;
	}
	</script>
	</body>
	</html>
	<?php
	// (A) PHP CONVERT ARRAY TO STRING
	$phpvar = json_encode(["Apple", "Banana", "Cherry"]);
	?>

	<!-- (B) JAVASCRIPT CONVERT STRING TO ARRAY -->
	<script>
	var jsvar = JSON.parse('<?=$phpvar?>');
	console.log(jsvar);
	</script>