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https://github.com/meyfa/php-svg

Vector graphics (SVG) library for PHP
https://github.com/meyfa/php-svg

library parser php php-svg png rasterizer rasterizing rendering svg svg-images vector-graphics

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Vector graphics (SVG) library for PHP

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README 

        
# PHP-SVG



**The zero-dependency vector graphics library for PHP applications**



[![CI](https://github.com/meyfa/php-svg/actions/workflows/php.yml/badge.svg)](https://github.com/meyfa/php-svg/actions/workflows/php.yml)

[![Maintainability](https://api.codeclimate.com/v1/badges/8f73468601a653aff0e8/maintainability)](https://codeclimate.com/github/meyfa/php-svg/maintainability)

[![Test Coverage](https://api.codeclimate.com/v1/badges/8f73468601a653aff0e8/test_coverage)](https://codeclimate.com/github/meyfa/php-svg/test_coverage)

![Packagist PHP Version](https://img.shields.io/packagist/dependency-v/meyfa/php-svg/php?style=plastic)

[![Packagist Downloads](https://img.shields.io/packagist/dt/meyfa/php-svg)](https://packagist.org/packages/meyfa/php-svg)



## Features



PHP-SVG can help with the following set of tasks:



* Generating vector graphics programmatically with PHP code. The resulting SVG string can be written to a file or sent

  as part of the HTTP response.

* Loading and parsing SVG images into document trees that are easy to modify and append.

* Converting vector graphics into raster image formats, such as PNG or JPEG (rasterization).



Please note that PHP-SVG is still in its alpha stage and may not be suitable for complex applications, yet.

Contributions are very welcome. [Find out how to contribute](#contributing).



## Installation



### Requirements



PHP-SVG is free of dependencies. All it needs is a PHP installation satisfying the following requirements:



* PHP version 7.4 or newer. This library is tested against all versions up to (and including) PHP 8.3.

* If you wish to load SVG files, or strings containing SVG code, you need to have the

  ['simplexml' PHP extension](https://www.php.net/manual/en/book.simplexml.php).

* If you wish to use the rasterization feature for converting SVGs to raster images (PNGs, JPEGs, ...), you need to

  have the ['gd' PHP extension](https://www.php.net/manual/en/book.image.php).



These extensions are almost always available on typical PHP installations. Still, you might want to make sure that your

hosting provider actually has them. If SimpleXML or GD are missing, PHP-SVG can still perform all tasks except those

that require the missing extension. For example, programmatically generating SVG images and outputting them as XML will

always work, even without any extension.



### Composer (recommended)



This package is available on [Packagist](https://packagist.org/packages/meyfa/php-svg) and can be installed with

Composer:



```bash

composer require meyfa/php-svg

```



This adds a dependency to your composer.json file. If you haven't already, setup autoloading for Composer dependencies

by adding the following `require` statement at the top of your PHP scripts:



```php

/autoloader.php';

```



The rest works exactly the same as with Composer, just without the benefits of a package manager.



## Getting started



This section contains a few simple examples to get you started with PHP-SVG.



### Creating SVGs programmatically



The following code generates an SVG containing a blue square. It then sets the Content-Type header and sends the SVG as

text to the client:



```php

getDocument();



// blue 40x40 square at the origin

$square = new SVGRect(0, 0, 40, 40);

$square->setStyle('fill', '#0000FF');

$doc->addChild($square);



header('Content-Type: image/svg+xml');

echo $image;

```



### Converting SVGs to strings



The above example uses `echo`, which implicitly converts the SVG to a string containing its XML representation. This

conversion can also be made explicitly:



```php

// This will include the leading  tag needed for standalone SVG files:

$xmlString = $image->toXMLString();

file_put_contents('my-image.svg', $xmlString);



// This will omit the  tag for outputting directly into HTML:

$xmlString = $image->toXMLString(false);

echo '
' . $xmlString . '
';

```



### Loading SVGs from strings



In addition to generating images programmatically from scratch, they can be parsed from strings or loaded from files.

The following code parses an SVG string, mutates part of the image, and echoes the result to the client:



```php

';

$svg .= '';

$svg .= '';



$image = SVG::fromString($svg);

$rect = $image->getDocument()->getElementById('my-rect');

$rect->setX(25)->setY(25);



header('Content-Type: image/svg+xml');

echo $image;

```



### Loading SVGs from files



For loading from a file instead of a string, call `SVG::fromFile($file)`. That function supports paths on the local

file system, as well as remote URLs. For example:



```php

// load from the local file system:

$image = SVG::fromFile('path/to/file.svg');



// or from the web (worse performance due to HTTP request):

$image = SVG::fromFile('https://upload.wikimedia.org/wikipedia/commons/8/8c/Even-odd_and_non-zero_winding_fill_rules.svg');

```



### Rasterizing



> :warning: **This feature in particular is very much work-in-progress.**

> Many things will look wrong and rendering large images may be very slow.



The `toRasterImage($width, $height [, $background])` method is used to render an SVG to a raster image. The result is

a GD image resource. GD then provides methods for encoding this resource to a number of formats:



* [imagepng](https://www.php.net/manual/en/function.imagepng.php)

* [imagejpeg](https://www.php.net/manual/en/function.imagejpeg.php)

* [imagebmp](https://www.php.net/manual/en/function.imagebmp.php)

* [imagegif](https://www.php.net/manual/en/function.imagegif.php)

* [imagewebp](https://www.php.net/manual/en/function.imagewebp.php)

* [imageavif](https://www.php.net/manual/en/function.imageavif.php) (requires PHP 8.1.0 or newer)



```php

getDocument();



// circle with radius 20 and green border, center at (50, 50)

$doc->addChild(

    (new SVGCircle(50, 50, 20))

        ->setStyle('fill', 'none')

        ->setStyle('stroke', '#0F0')

        ->setStyle('stroke-width', '2px')

);



// rasterize to a 200x200 image, i.e. the original SVG size scaled by 2.

// the background will be transparent by default.

$rasterImage = $image->toRasterImage(200, 200);



header('Content-Type: image/png');

imagepng($rasterImage);

```



The raster image will default to preserving any transparency present in the SVG. For cases where an opaque image is

desired instead, it is possible to specify a background color. This may be mandatory when outputting to some formats,

such as JPEG, that cannot encode alpha channel information. For example:



```php

// white background

$rasterImage = $image->toRasterImage(200, 200, '#FFFFFF');

imagejpeg($rasterImage, 'path/to/output.jpg');

```



### Text rendering (loading fonts)



PHP-SVG implements support for TrueType fonts (`.ttf` files) using a handcrafted TTF parser. Since PHP doesn't come

with any built-in font files, you will need to provide your own. The following example shows how to load a set of font

files. PHP-SVG will try to pick the best matching font for a given text element, based on algorithms from the CSS spec.



```php



  

  

    hello world

    in bold!

    and italic!

    bold and italic

  



');



header('Content-Type: image/png');

imagepng($image->toRasterImage(220, 220));

```



Note that PHP often behaves unexpectedly when using relative paths, especially with fonts. Hence, it is recommended to

use absolute paths, or use the `__DIR__` constant to prepend the directory of the current script.



## Document model



This section explains a bit more about the object structure and how to query or mutate parts of documents.



### SVG root node



An instance of the `SVG` class represents the image abstractly. It does not store DOM information itself. That is the

responsibility of the document root node, which is the object corresponding to the `` XML tag. For example:



```php

';

$svg .= '';

$svg .= '';



$image = SVG::fromString($svg);



// obtain the  node (an instance of \SVG\SVGDocumentFragment):

$doc = $image->getDocument();

```



### Child nodes



Child nodes of any element can be obtained as follows:



```php

// Returns the number of children.

$numberOfChildren = $element->countChildren();



// Returns a child element by its index.

$firstChild = $element->getChild(0);



// Returns an array of matching child elements.

$childrenThatAreRects = $element->getElementsByTagName('rect');



// Returns an array of matching child elements.

$childrenWithClass = $element->getElementsByClassName('my-class-name');

```



The root node has an additional function for obtaining a unique element by its `id` attribute:



```

// Returns an element or null.

$element = $doc->getElementById('my-rect');

```



Child nodes can be added, removed and replaced:



```php

// Append a child at the end.

$doc->addChild(new \SVG\Nodes\Shapes\SVGLine(0, 0, 10, 10));



// Insert a new child between the children at positions 0 and 1.

$g = new \SVG\Nodes\Structures\SVGGroup();

$doc->addChild($g, 1);



// Remove the second child. (equivalent to $doc->removeChild($g);)

$doc->removeChild(1);



// replace the first child with $g

$doc->setChild(0, $g);

```



### Attributes



Every attribute is accessible via `$element->getAttribute($name)`. Some often-used attributes have additional shortcut

methods, but they are only available on the classes for which they are valid, so make sure the node you are accessing

is of the correct type to prevent runtime errors. Some examples:



```php

$doc->getWidth();

// equivalent to: $doc->getAttribute('width')



$doc->setWidth('200px');

// equivalent to: $doc->setAttribute('width', '200px');



$rect->setRX('10%');

// equivalent to: $rect->setAttribute('rx', '10%');

```



### Styles



Some presentation attributes are considered style properties by the SVG spec. These will be treated specially by

PHP-SVG and made available via `getStyle` and `setStyle` instead of `getAttribute` and `setAttribute`.

Consider the following node:



```xml



```



* `x`, `y` and `r` are attributes.

* `fill`, `stroke` and `stroke-width` are styles.



## Debugging



If you aren't getting any output but only a blank page, try temporarily enabling PHP's error reporting to find the cause

of the problem.



```php