Php – When I click on export this error occurs in phptheadmin

MySQLPHPphpmyadminWordpress

Warning in ./../../php/tcpdf/include/tcpdf_fonts.php#1671
chr() expects parameter 1 to be int, string given

Backtrace

tcpdf_fonts.php#1671: chr(string '')
tcpdf_fonts.php#1803: TCPDF_FONTS::unichr(
string '',
boolean true,
)
tcpdf_fonts.php#2095: TCPDF_FONTS::UTF8ArrSubString(
array,
integer 0,
integer 1,
boolean true,
)
tcpdf.php#1960: TCPDF_FONTS::utf8Bidi(
array,
string '',
boolean false,
boolean true,
NULL,
)
./libraries/classes/Pdf.php#50: TCPDF->__construct(
string 'L',
string 'pt',
string 'A3',
boolean true,
string 'UTF-8',
boolean false,
boolean false,
)
./libraries/classes/Plugins/Export/Helpers/Pdf.php#58: PhpMyAdmin\Pdf->__construct(
string 'L',
string 'pt',
string 'A3',
boolean true,
string 'UTF-8',
boolean false,
boolean false,
)
./libraries/classes/Plugins/Export/ExportPdf.php#70: PhpMyAdmin\Plugins\Export\Helpers\Pdf->__construct(
string 'L',
string 'pt',
string 'A3',
)
./libraries/classes/Plugins/Export/ExportPdf.php#55: PhpMyAdmin\Plugins\Export\ExportPdf->initSpecificVariables()enter image description here
./libraries/classes/Plugins.php#99: PhpMyAdmin\Plugins\Export\ExportPdf->__construct()
./libraries/classes/Display/Export.php#677: PhpMyAdmin\Plugins::getPlugins(
string 'export',
string 'libraries/classes/Plugins/Export/',
array,
)
./db_export.php#147: PhpMyAdmin\Display\Export->getDisplay(
string 'database',
string 'wordpress',
string '',
string '',
integer 14,
integer 0,
string 'TablesStructureDataSelect all wp_commentmetawp_commentswp_linkswp_optionswp_postmetawp_postswp_termmetawp_termswp_term_relationshipswp_term_taxonomywp_usermetawp_userswp_yoast_seo_linkswp_yoast_seo_meta ',
)

Best Answer

I have fixed this issue simply I have upgraded the PHPMyAdmin and MYSQL latest version.

Short Answer

Use $this to refer to the current object. Use self to refer to the current class. In other words, use $this->member for non-static members, use self::$member for static members.

Full Answer

Here is an example of correct usage of $this and self for non-static and static member variables:

<?php
class X {
    private $non_static_member = 1;
    private static $static_member = 2;

    function __construct() {
        echo $this->non_static_member . ' '
           . self::$static_member;
    }
}

new X();
?>

Here is an example of incorrect usage of $this and self for non-static and static member variables:

<?php
class X {
    private $non_static_member = 1;
    private static $static_member = 2;

    function __construct() {
        echo self::$non_static_member . ' '
           . $this->static_member;
    }
}

new X();
?>

Here is an example of polymorphism with $this for member functions:

<?php
class X {
    function foo() {
        echo 'X::foo()';
    }

    function bar() {
        $this->foo();
    }
}

class Y extends X {
    function foo() {
        echo 'Y::foo()';
    }
}

$x = new Y();
$x->bar();
?>

Here is an example of suppressing polymorphic behaviour by using self for member functions:

<?php
class X {
    function foo() {
        echo 'X::foo()';
    }

    function bar() {
        self::foo();
    }
}

class Y extends X {
    function foo() {
        echo 'Y::foo()';
    }
}

$x = new Y();
$x->bar();
?>

The idea is that $this->foo() calls the foo() member function of whatever is the exact type of the current object. If the object is of type X, it thus calls X::foo(). If the object is of type Y, it calls Y::foo(). But with self::foo(), X::foo() is always called.

From http://www.phpbuilder.com/board/showthread.php?t=10354489:

By http://board.phpbuilder.com/member.php?145249-laserlight

Php – Reference – What does this error mean in PHP

Warning: Cannot modify header information - headers already sent

Happens when your script tries to send an HTTP header to the client but there already was output before, which resulted in headers to be already sent to the client.

This is an E_WARNING and it will not stop the script.

A typical example would be a template file like this:

<html>
    <?php session_start(); ?>
    <head><title>My Page</title>
</html>
...

The session_start() function will try to send headers with the session cookie to the client. But PHP already sent headers when it wrote the <html> element to the output stream. You'd have to move the session_start() to the top.

You can solve this by going through the lines before the code triggering the Warning and check where it outputs. Move any header sending code before that code.

An often overlooked output is new lines after PHP's closing ?>. It is considered a standard practice to omit ?> when it is the last thing in the file. Likewise, another common cause for this warning is when the opening <?php has an empty space, line, or invisible character before it, causing the web server to send the headers and the whitespace/newline thus when PHP starts parsing won't be able to submit any header.

If your file has more than one <?php ... ?> code block in it, you should not have any spaces in between them. (Note: You might have multiple blocks if you had code that was automatically constructed)

Also make sure you don't have any Byte Order Marks in your code, for example when the encoding of the script is UTF-8 with BOM.

Best Answer

Related Solutions

Php – When should I use ‘self’ over ‘$this’

Short Answer

Full Answer

Php – Reference – What does this error mean in PHP

Warning: Cannot modify header information - headers already sent

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