Image operators #

Three operators of eZTemplateImageOperator (lib/eztemplate/classes/eztemplateimageoperator.php), registered through lib/eztemplate/classes/eztemplateautoload.php, work with images through PHP's GD extension (the class checks for ImageTTFBBox, ImageCreate, ImageTTFText, ImagePNG and the other functions it needs, and logs an error instead of working when one is missing):

• texttoimage renders a text as a PNG image with a TrueType font;
• image combines layers into one image;
• imagefile reads an existing image file.

They have nothing to do with the images of content objects, which come from the image datatype and its aliases. All three return an image object (eZImageLayer, eZImageTextLayer or eZImageObject), which prints as an <img> tag and offers the attributes filepath, filename, width, height, alternative_text, imagepath and has_size.

Contents #

1. Settings: texttoimage.ini
2. texttoimage
3. image
4. imagefile
5. Related pages

Settings: texttoimage.ini #

settings/texttoimage.ini holds the paths and the font classes:

texttoimage #

texttoimage #

Renders the piped text with the font settings of a class, overridden by any parameter given. The image is written to <CacheDir>/imagetext/ under a name made from an MD5 of the text and the settings; with UseCache an existing file is reused.

Input: the text, piped. Returns an eZImageTextLayer. When the font is not found it returns nothing; when the font cannot be opened it logs "Could not open font". Generated reference: texttoimage.

It writes files. The template below was rendered once on a development installation while this page was prepared, and it created the directory var/cache/texttoimage/imagetext/ with the PNG file (a cache directory: it can be cleared, and the image is made again on the next request):

{'Fit & Healthy'|texttoimage( '1942' )}

Its output:

<img border="0" src="/var/cache/texttoimage/imagetext/b/d/3/bd3fdc7ef41d4f843b93d8d9703be5d4/Fit_amp_Healthy.png" alt="Fit &amp;amp; Healthy" width="450" height="52" />

Note the alt text: the operator escapes the text with htmlspecialchars() when it creates the layer ($alternativeText), and the <img> output escapes it again, so & arrives as &. Pass text without characters that need escaping, or write the <img> tag yourself from imagepath, width and height.

image #

image #

Builds one image from layers. Every parameter is either a string, which becomes the alternative text, or an array of a layer and a hash of placement options: halign (left, right, center), valign (top, bottom, center), x, y, xrel, yrel and transparency. The result is written to <CacheDir>/imageobject/ (reused with UseCache).

Input: none. Returns an eZImageObject. Generated reference: image.

It writes files, like texttoimage. This template, also rendered once on a development installation, created var/cache/texttoimage/imageobject/:

{image( array( 'Fit & Healthy'|texttoimage( '1942' ), hash( 'halign', 'center', 'valign', 'center' ) ), 'Fit and Healthy' )}

Its output:

<img border="0" src="/var/cache/texttoimage/imageobject/5/e/1/5e1e308e65728a71d3bcfdcfd00dbd81/Fit_and_Healthy.png" alt="Fit and Healthy" width="450" height="52" />

imagefile #

imagefile #

Reads an image file and returns it as a layer: eZImageLayer::createForFile() reads the size with getimagesize() and loads the image into memory. Nothing is written. The alternative text is the file name without its extension.

Input: none. Returns an eZImageLayer, which can be used as a layer of image. Generated reference: imagefile.

{def $img = imagefile( 'design/standard/images/add.png' )}
filepath: {$img.filepath}
filename: {$img.filename}
size: {$img.width} x {$img.height} (has_size: {$img.has_size|choose( 'no', 'yes' )})
alternative_text: {$img.alternative_text}

Output:

filepath: design/standard/images
filename: add.png
size: 16 x 16 (has_size: yes)
alternative_text: add

The imagefile example gave the same output compiled on a development installation. The two writing examples were not run a second time, interpreted or compiled.

Related pages #

• Icon operators: icons for classes, MIME types and flags
• Image datatype examples: images of content objects
• All template operators (generated)
• Free documentation: this page is free to copy, translate and improve under the GNU FDL 1.3.