Table of Contents

• Introduction
  • Compatibility
• Prerequisites
  • OSX (High Sierra)
• Installation
• Development
• Scales
  • "get_logo" scale
• Converter
• ZCML
• Logo View
• Caching
• Links
• Copyright

Introduction

Plone extension providing smart logo handling. Based on an svg Logo or Icon the extension is able to produce all kinds of scales such as apple touch icons or android PWA logos.

Compatibility

Plone 4.3.x Plone 5.1.x

Prerequisites

See wand.py dependencies

OSX (High Sierra)

Two important points for developers.

If you experience problems converting some svg's to png's, like getting a all transparent PNG. Install imagemagick with librsvg. Also don't install imagemagick version 7. Not gonna work.

brew install imagemagick@6 --with-librsvg
brew link imagemagick@6 --force

Also make sure /usr/local/opt/imagemagick@6/bin is in the PATH

Installation

• Add the package to your buildout configuration:

[instance]
eggs +=
    ...
    ftw.logo

Development

1. Fork this repo
2. Clone your fork
3. Shell: ln -s development.cfg buildout.cfg
4. Shell: python bootstrap.py
5. Shell: bin/buildout

Run bin/test to test your changes.

Or start an instance by running bin/instance fg.

Scales

Basically there are just logo and icon scales. The logo scales are mostly used on the top left and can have any dimensions. The converter creates a logo and mobile_logo from the base logo which has to be an svg file. The icon scales are used for apple_touch_icons, favicons or android PWA icons. The base icon must be square, and the scaled icons will also if course be square. In summary we need two different SVG source files. One with an arbitary ratio and the other with a square ratio.

All scales are taken from https://realfavicongenerator.net/.

The available scales are:

• LOGOS

  • LOGO
  • MOBILE_LOGO
  • BASE
  • get_logo (virtual)

• ICONS

  • APPLE_TOUCH_ICON
  • FAVICON_32X32
  • FAVICON_16X16
  • MSTILE_150X150
  • ANDROID_192X192
  • ANDROID_512X512
  • FAVICON
  • BASE

"get_logo" scale

The get_logo virtual scale returns either the BASE (svg from ZCML) or if available the overridden BASE or LOGO scale from the Dexterity content type.

Converter

The converter holds all the scale definitions and so is able to generate the scales needed. wand.py is used to convert the svg source files into the different scales. The converter generates a modified wand.py image proxy which is able to return the actual blob of the scale behind the proxy. Refer to the write images and resizing and cropping section for more information about how the converter uses wand.py.

ZCML

The extension introduces a custom icon and logo directive for zcml. Both directives accept for, layer and base attributes. The base attribute defines the svg source files for all scales. The multiadapter adapts context and request. So the svg source file can be overridden by using one or both of for and layer.

First include the directive:

<configure
 ...
 xmlns:logo="https://namespaces.4teamwork.ch/ftw.logo"
 ...
 >

Example:

<logo:logo base="logo.svg" />

The next block will override the previous config.

<logo:logo base="custom_logo.svg" layer="your.product.interfaces.IYourProductLayer" />

It's also possible to define a pre scaled image for logo, mobile and favicon.

<logo:logo base="resources/min.svg"
           logo="tests/fixtures/logo.png"
           mobile="mobile.png"
           primary_logo_scale="logo" />

<logo:icon base="icon.svg" favicon="favicon.ico" />

Please remember a base svg is required anyway. If you can't supply one, simply put in a transparent empty svg. If you dont't have one you can use the one from this package, which is located in the resources folder. It's called min.svg. Also set the primary_logo_scale to "logo", since ftw.logo always prefers the svg over all other scales.

Change default height for logo and mobile scale by zcml:

<logo:logo base="resources/min.svg"
           height="200"
           mobile_height="30" />

Logo View

All logos and icons can be accessed through the logo browser view. The URL consists of the browser view name @@logo followed by the type of the image and the actual scale.

Examples:

• @@logo/logo/BASE will show the svg logo source.
• @@logo/icon/APPLE_TOUCH_ICON will show the apple touch icon as a png image.

Caching

Caching is provided by adding a query string parameter to every logo request. The cachekey consist of a sha256 hash including the files binary data. If you have plone.app.caching enabled, install the caching profile from ftw.logo. This will define etag values so the viewlet is cached properly.

Links

• Github: https://github.com/4teamwork/ftw.logo
• Issues: https://github.com/4teamwork/ftw.logo/issues
• Pypi: http://pypi.python.org/pypi/ftw.logo

Copyright

This package is copyright by 4teamwork.

ftw.logo is licensed under GNU General Public License, version 2.