This package offers a simple way to develop and deploy Plone themes using the Diazo theming engine. If you are not familiar with Diazo, check out the Diazo documentation.

It comes with a user guide, reproduced below, available through the theming control panel.

plone.app.theming manual

This guide provides an overview of Diazo theming in Plone versions 4.3 and higher.

Introduction

In Plone versions 4.3 and higher you can edit your website theme through web browser in Plone's site setup control panel. Only HTML, CSS and little XML knowledge needed as the prerequisitements. This guide explains how to use this feature of Plone.

See introduction video to plone.app.theming.

What is a Diazo theme?

A "theme" makes a website (in this case, one powered by Plone) take on a particular look and feel.

Diazo (formerly known as XDV) is a technology that can be used to theme websites. It is not specific to Plone per se, but has been created by the Plone community and, as of Plone 4.3, provides the default way to apply a theme to a Plone site. You can learn more about Diazo at .

Diazo themes may be a little different to themes you have created in other systems, and indeed to themes you may have created for earlier versions of Plone. A Diazo theme is really about transforming some content - in this case the output from "vanilla" Plone - into a different set of HTML markup by applying a set of rules to combine a static HTML mock-up of the end result you want with the dynamic content coming from Plone.

In comparison, the previous way to theme a Plone site (like the way many other content management systems are themed) relies on selectively overriding the templates and scripts that Plone uses to build a page with custom versions that produce different HTML markup. The latter approach can be more powerful, certainly, but also requires much deeper knowledge of Plone's internals and command of server-side technologies such as Zope Page Templates and even Python. Diazo themes, by contrast, are easy to understand for web designers and non-developers alike.

A Diazo theme consists of three elements:

1. One or more HTML mockups, also referred to as theme files, that represent the desired look and feel.

   These will contain placeholders for content that is to be provided by the Plone content management system. Mockups usually reference CSS, JavaScript and image files by relative path. The most common way to create a theme is to use desktop software like Dreamweaver or a text editor to create the relevant markup, styles and scripts, and test the theme locally in a web browser.

2. The content that is being themed. In this case, that is the output from Plone.

3. A rules file, which defines how the placeholders in the theme (i.e. the HTML mockup) should be replaced by relevant markup in the content.

   The rules file uses XML syntax (similar to HTML). Here is a very simple example:

   `
   

   Here, we are replacing the contents (child nodes) of a placeholder element with HTML id main in the theme file (theme.html, found in the same directory as the rules.xml file, as referenced by the `` rule) with the contents (children) of the element with the HTML id content in the markup generated by Plone.

   When this theme is applied, the result will look very much like the static HTML file theme.html (and its referenced CSS, JavaScript and image files), except the placeholder that is identified by the node in the theme with id main will be filled by Plone's main content area.

Plone ships with an example theme called, appropriately, Example theme, which uses the venerable Twitter Bootstrap to build a simple yet functional theme exposing most of Plone's core functionality. You are advised to study it - in particular the rules.xml file - to learn more about how Diazo themes work.

Using the control panel

After installation of the Diazo theme support package in a Plone site, the Theming control panel will appear in Plone's Site setup.

The main tab of this control panel, Themes, will show all available themes, with buttons to activate/deactivate, modify, copy or delete each, as well as buttons to create new themes or bring up this help text.

Click on a theme preview image to open a preview of that theme in a new tab or window. The preview is navigable, but form submissions and some advanced features will not work.

Selecting a theme

To apply an existing theme, simply click the Activate button underneath the theme preview. The currently active theme will be highlighted in yellow. If you deactivate the currently active theme, no Diazo theme will be applied, i.e. "vanilla" Plone theming will apply.

Note: The Theming control panel is never theemd, ensuring that you can always deactivate an errant theme that could render the control panel unusable. Thus, you may not see any difference immediately after enabling a theme. Simply navigate to another page in the Plone site, though, and you should see the theme applied.

Creating a new theme

New themes can be created in one of two ways:

• Click the New theme button at the top of the Themes tab in the Theming control panel and enter a title and description in the form that appears. A bare-bones theme will be created, and you will be taken to the Modify theme screen (see below), where you can edit or create theme and rules files.
• Click the Copy button underneath any existing theme and enter a title and description in the form that appears. A new theme will be created as a copy of the existing theme, and you will be taken to the Modify theme (see below), where you can edit or create theme and rules files.

Uploading an existing theme

Themes can be distributed as Zip files, containing the HTML mockup and rules file. To download an existing theme, click the Download button underneath the theme on the Themes tab of the Theming control panel.

To upload such a Zip file into another site, use the Upload Zip file button on the Themes tab of the Theming control panel. You can choose whether or not to replace any existing theme with the same name (based on the name of the top-level directory contained within the Zip file).

You can also upload a Zip file of a static HTML mockup that does not contain a rules file, such as a design provided by a Plone-agnostic web designer.

In this case, a basic rules.xml file will be added for you to start building up a theme from using the Modify theme screen (see below). The generated rules file will assume the main HTML mockup file is called index.html, but you can change this in rules.xml.

Once you have successfully uploaded a theme Zip file, you will be taken to the Modify theme screen (see below), where you can edit or create theme files.

Hint: If you get an error message like "The uploaded file does not contain a valid theme archive", this usually means that you have uploaded a Zip file that contains multiple files and folders, rather than a single top level folder with all the theme resources in it. This could happen if you compressed a theme or HTML mockup by adding its files and folders directly a Zip archive, rather than compressing the directory in which they were found. To fix this, simply unzip the archive on your computer into a new directory, move up a level, and compress this directory on its own into a new Zip file, which you can then upload.

Modifying the theme

You can modify a theme by clicking Modify theme underneath a theme in the Themes tab of the Theming control panel. This screen is also launched automatically when you create or upload a new theme.

Note: Only themes created or uploaded through the Theming control panel can be modified through Plone. Themes installed by third-party add-ons or distributed on the filesystem cannot, although changes made on the filesystem will be reflected immediately if Zope is running in debug mode. To modify a filesystem theme, you can copy it to a new in-Plone theme by clicking the Copy button underneath the theme in the Theming control panel.

The Modify theme screen initially shows a file manager, with a file tree on the left and an editor on the right. Click on a file in the file tree to open an editor or preview: HTML, CSS, JavaScript and other text files can be edited directly through the editor. Other files (e.g. images) will be rendered as a preview.

Note: The advanced editor with syntax highlighting is not available in Microsoft Internet Explorer.

Click New folder to create a new folder. You can also right-click on a folder in the file tree to bring up this action.

Click New file to create a new text file. You can also right-click on a folder in the file tree to bring up this action.

Click Upload file to upload a file from your computer. You can also right-click on a folder in the file tree to bring up this action.

Click Preview theme to preview the theme as it will be applied with the mockup and rules as currently saved. The preview is navigable, but forms and certain advanced features will not work.

To save the file currently being edited, click the Save file button, or use the keyboard shortcut Ctrl+S (Windows/Linux) or Cmd+S (Mac).

To rename or delete a file or folder, right-click on it in the file tree and select the appropriate action.

The theme inspector

The theme inspector provides an advanced interface for discovering and building up the rules of a Diazo theme. It can be launched by clicking the Show inspectors button on the Modify theme screen for in-Plone themes, or by clicking the Inspect theme button underneath a filesystem theme on the Themes tab of the Theming control panel.

The theme inspector consists of two panels:

• The HTML mockup. If there are several HTML files in the theme, you can switch between them using the drop-down list underneath the HTML mockup panel.
• The Unthemed content. This shows Plone without any theme applied.

Either panel can be maximised by clicking the arrows icon at the top right of either.

The HTML mockups and Unthemed content panels can be switch to source view, showing their underlying HTML markup, by clicking the tags icon at the top right of either.

As you hover over elements in the HTML mockup or Unthemed content panels, you will see:

• An outline showing the element under the cursor.
• A CSS or XPath selector in the status bar at the bottom if the panel which would uniquely identify this element in a Diazo rule.

Click on an element or press Enter whilst hovering oveer an element to select it. The most recently selected element in each panel is shown in the bottom right of the relevant status bar.

Press Esc whilst hovering over an element to select its parent. This is useful when trying to select "invisible" container elements. Press Enter to save this selection.

The contents of the HTML mockup or (more commonly) Unthemed content panels can be navigated, for example to get to a content page that requires specific theme rules, by disabling the inspector. Use the toggle switches at the bottom right of the relevant panel to enable or disable the selector.

The rule builder

Click the Build rule button near the top of the Modify theme or Inspect theme screen to launch an interactive rule building wizard. You will be asked which type of rule to build, and then prompted to select the relevant elements in the HTML mockup and/or Unthemed content panels as required. By default, this will use any saved selections, unless you untick the Use selected elements box on the first page if the wizard.

Once the wizard completes, you will be shown the generated rule. You can edit this if you wish. If you click Insert, the newly generated rule will be inserted into the rules.xml editor at or near your current cursor position. You can move it around or edit it further as you wish.

Click Preview theme to preview the theme in a new tab or window. Don't forget to save the rules.xml file if you have made changes.

Note: In readonly mode, you can build rules and inspect the HTML mockup and theme, but not change the rules.xml file. In this case, the Insert button of the rule builder (see below) will not be available either.

Note: The ability to insert rules from the Build rule wizard are not available in Microsoft Internet Explorer, although you will be given the option to copy the rule to the clipboard when using this browser.

Advanced settings

The Theming control panel also contains a tab named Advanced settings. Here be dragons.

The Advanced settings tab is divided into two areas. The first, Theme details, contains the underlying settings that are modified when a theme is applied from the Themes control panel. These are:

• Whether or not Diazo themes are enabled at all.
• The path to the rules file, conventionally called rules.xml, either relative to the Plone site root or as an absolute path to an external server.
• The prefix to apply when turning relative paths in themes (e.g. references to images in an <img> tag's src attribute) into absolute ones at rendering time.
• The HTML DOCTYPE to apply to the rendered output, if different to the default XHTML 1.0 Transitional.
• Whether or not to allow theme resources (likes rules.xml) to be read from the network. Disabling this gives a modest performance boost.
• A list of host names for which a theme is never applied. Most commonly, this contains 127.0.0.1, allowing you to view an unthemed site through http://127.0.0.1:8080 and a themed one at http://localhost:8080 during development, say.
• A list of theme parameters and the TALES expressions to generate them (see below).

The second, Theme base, controls the presentation of the unthemed content, and apply even if no Diazo theme is being applied. These are the settings that used to be found in the Themes control panel in previous versions of Plone.

Reference

The remainder of this guide contains reference materials useful for theme builders.

Deploying and testing themes

To build and test a theme, you must first create a static HTML mockup of the look and feel you want, and then build a rules file to describe how Plone's content maps to the placeholders in this mockup.

The mockup can be created anywhere using whatever tool you feel most comfortable building web pages in. To simplify integration with Plone, you are recommended to make sure it uses relative links for resources like CSS, JavaScript and image files, so that it will render properly when opened in a web browser from a local file. Plone will convert these relative links to the appropriate absolute paths automatically, ensuring the theme works no matter which URL the user is viewing when the theme is applied to a Plone site.

There are several ways to get the theme into Plone:

1. On the filesystem

   If you used an installer or a standard "buildout" to set up your Plone site, you should have a directory called resources in the root of your Plone installation (this is created using the resources option to the buildout recipe plone.recipe.zope2instance. See for more details.)

   You can find (or create) a theme directory inside this directory, which is used to contain themes. Each theme needs its own directory with a unique name. Create one (e.g. resources/theme/mytheme) and put your HTML files and any references resources inside this directory. You can use subdirectories if you wish, but you are recommended to keep the basic theme HTML files at the top of the theme directory.

   You will also need a rules file called rules.xml inside this directory. If you haven't got one yet, start with an empty one:

   `
   

   Provided you are running Zope in debug mode (e.g. you start it up with bin/instance fg), changes to the theme and rules should take effect immediately. You can preview or enable the theme through the Themes control panel, and then iteratively modify the rules.xml file or the theme mockup as you wish.

2. Through the web

   If you prefer (or do not have filesystem access), you can create themes entirely through the Plone control panel, either by duplicating an existing theme, or starting from scratch with a near-empty theme.

   See the instructions on using the control panel above for more details.

   Once a theme has been created, you can modify it through the Theming control panel. See above for more details.

3. As a zip file

   Themes can be downloaded from Plone as Zip files, which can then be uploaded into other sites.

   See the instructions on using the control panel above for more details.

   In fact, you can create valid theme zip archives by compressing a theme directory on the filesystem using a standard compression tool such as 7-Zip or Winzip (for Windows) or the built-in Compress action in the Mac OS X Finder. Just make sure you compress exactly one folder that contains all the theme files and the rules.xml file. (Do not compress the contents of the folder directly: when unpacked, the zip file should produce exactly one folder which in turn contains all the relevant files).

4. In a Python package (programmers only)

   If you are creating a Python package containing Plone customisations that you intend to install into your site, you can let it register a theme for installation into the site.

   To do this, place a directory called e.g. theme at the top of the package, next to the Zope configure.zcml file, and add a `` declaration to the configure.zcml file:

       ...
   
       
   
       ...
   

   Notice the declaration of the plone namespace at the root `` element. Place the theme files and the rules.xml file into the theme directory.

   If your package has a GenericSetup profile, you can automatically enable the theme upon installation of this profile by adding a theme.xml file in the profiles/default directory, containing e.g.:

       mytheme
       true
   

The manifest file

It is possible to give additional information about a theme by placing a file called manifest.cfg next to the rules.xml file at the top of a theme directory.

This file may look like this:

[theme]
title = My theme
description = A test theme
rules = http://example.org/myrules.xml
prefix = /some/prefix
doctype = 
preview = preview.png
enabled-bundles = mybundle
disabled-bundles = plone
development-css = /++theme++barceloneta/css/barceloneta.css
production-css = /++theme++barceloneta/css/barceloneta.min.css
development-js = /++theme++barceloneta/barceloneta.js
production-js = /++theme++barceloneta/barceloneta.min.js
tinymce-content-css = /++theme++barceloneta/barceloneta.min.css
tinymce-styles-css = /++theme++barceloneta/custom-styles.css

As shown here, the manifest file can be used to provide a more user friendly title and a longer description for the theme, for use in the control panel. Only the [theme] header is required - all other keys are optional.

Manifest settings:

rules
to use a different rule file name than rules.xml (you should provide a URL or relative path).

prefix
To change the absolute path prefix (see Advanced settings), use:

prefix = /some/prefix

doctype
To employ a DOCTYPE in the themed content other than XHTML 1.0 Transitional, add e.g.:

doctype = 

preview
To provide a user-friendly preview of your theme in the Theming control panel. Here, preview.png is an image file relative to the location of the manifest.cfg file:

preview = preview.png

enabled-bundles
Bundles that will automatically be enabled when a theme is activated

disabled-bundles
Bundles that will automatically be disabled when a theme is activated

development-css
CSS to automatically include when in development mode and theme is active

development-js
JavaScript file to automatically include when in development mode when theme is active

production-css
CSS to automatically include when theme is active and in production mode

production-js
JavaScript to automatically include when theme is active and in production mode

tinymce-content-css
CSS file tinymce should load to apply styles to content inside the editor

tinymce-styles-css
CSS file tinymce should load to provide additionally automatically detected drop-down styles in the editor

Extensions to the Diazo theming engine can add support for additional blocks of configurable parameters.

Rules syntax

The following is a short summary of the Diazo rules syntax. See for more details and further examples.

Selectors

Each rule is represented by an XML tag that operates on one or more HTML elements in the content and/or theme. The elements to operate on are indicated using attributes of the rules known as selectors.

The easiest way to select elements is to use a CSS expression selector, such as css:content="#content" or css:theme="#main .content". Any valid CSS 3 expression (including pseudo-selectors like :first-child may be used.

The standard selectors, css:theme and css:content, operate on the element(s) that are matched. If you want to operate on the children of the matched element instead, use css:theme-children="..." or css:content-children="..." instead.

If you cannot construct a suitable CSS 3 expression, you can use XPath expressions such as content="/head/link" or theme="//div[@id='main']" (note the lack of a css: prefix when using XPath expressions). The two approaches are equivalent, and you can mix and match freely, but you cannot have e.g. both a css:theme and a theme attribute on a single rule. To operate on children of a node selected with an XPath expression, use theme-children="..." or content-children="...".

You can learn more about XPath at .

Conditions

By default, every rule is executed, though rules that do not match any elements will of course do nothing. You can make a rule, set of rules or theme reference (see below) conditional upon an element appearing in the content by adding an attribute to the rule like css:if-content="#some-element" (to use an XPath expression instead, drop the css: prefix). If no elements match the expression, the rule is ignored.

Tip: if a `` rule matches an element in the theme but not in the content, the theme node will be dropped (replaced with nothing). If you do not want this behavior and you are unsure if the content will contain the relevant element(s), you can use css:if-content conditional rule. Since this is a common scenario, there is a shortcut: css:if-content="" means "use the expression from the css:content attribute".

Similarly, you can construct a condition based on the path of the current request by using an attribute like if-path="/news" (note that there is no css:if-path ). If the path starts with a slash, it will match from the root of the Plone site. If it ends with a slash, it will match to the end of the URL. You can set an absolute path by using a leading and a trailing slash.

Finally, you can use arbitrary XPath expressions against any defined variable using an attribute like if="$host = 'localhost'" . By default, the variables url , scheme , host and base are available, representing the current URL. Themes may define additional variables in their manifests.

Available rules

The various rule types are summarized below.

rules

    ...

Wraps a set of rules. Must be used as the root element of the rules file. Nested `` can be used with a condition to apply a single condition to a set of rules.

When used as the root element of the rules file, the various XML namespaces must be declared:

    ...

theme and notheme

Choose the theme file to be used. The href is a path relative to the rules file. If multiple `` elements are present, at most one may be given without a condition. The first theme with a condition that is true will be used, with the unconditional theme, if any, used as a fallback.

can be used to specify a condition under which no theme should be used. takes precedence over ``.

Tip: To ensure you do not accidentally style non-Plone pages, add a condition like css:if-content="#visual-portal-wrapper" to the last theme listed, and do not have any unconditional themes.

replace

Replaces the matched element(s) in the theme with the matched element(s) from the content.

before and after

Inserts the matched element(s) from the content before or after the matched element(s) in the theme. By using theme-children , you can insert the matched content element(s) as the first (prepend) or last (append) element(s) inside the matched theme element(s).

drop and strip

Remove element(s) from the theme or content. Note that unlike most other rules, a or rule can operate on the theme or content , but not both. removes the matched element(s) and any children, whereas removes the matched element(s), but leaves any children in place.

`` may be given a whitespace-separated list of attributes to drop. In this case, the matched element(s) themselves will not be removed. Use attributes="*" to drop all attributes.

merge and copy

These rules operate on attributes. `` will add the contents of the named attribute(s) in the theme to the value(s) of any existing attributes with the same name(s) in the content, separated by whitespace. It is mainly used to merge CSS classes.

`` will copy attributes from the matched element(s) in the content to the matched element(s) in the theme, fully replacing any attributes with the same name that may already be in the theme.

The attributes attribute can contain a whitespace-separated list of attributes, or the special value * to operate on all attributes of the matched element.

Advanced modification

Instead of selecting markup to insert into the theme from the content, you can place markup directly into the rules file, as child nodes of the relevant rule element:

    <style type="text/css">
        body > h1 { color: red; }
    </style>

This also works on the content, allowing you to modify it on the fly before any rules are applied:

    <button type="submit">
        <img alt="Search" src="images/search.png">
    </button>

In addition to including static HTML in this manner, you can use XSLT instructions that operate on the content. You can even use css: selectors directly in the XSLT.:

    <dl id="details">
        
            <dt></dt>
            <dd></dd>
        
    </dl>

Rules may operate on content that is fetched from somewhere other than the current page being rendered by Plone, by using the href attribute to specify a path of a resource relative to the root of the Plone site:

Theme parameters

It is possible to pass arbitrary parameters to your theme, which can be referenced as variables in XPath expressions. Parameters can be set in Plone's theming control panel, and may be imported from a manifest.cfg file.

For example, you could have a parameter mode that could be set to the string live or test. In your rules, you could do something like this to insert a warning when you are on the test server:

    <span class="warning">Warning: This is the test server</span>

You could even use the parameter value directly, e.g.:

    <span class="info">This is the  server</span>

The following parameters are always available to Plone themes:

scheme
The scheme portion of the inbound URL, usually http or https.

host
The hostname in the inbound URL.

path
The path segment of the inbound URL. This will not include any virtual hosting tokens, i.e. it is the path the end user sees.

base
The Zope base url (the BASE1 request variable).

You can add additional parameters through the control panel, using TALES expressions. Parameters are listed on the Advanced tab, one per line, in the form =.

For example, if you want to avoid theming any pages that are loaded by Plone's overlays, you can make use of the ajax_load request parameter that they set. Your rules file might include:

To add this parameter as well as the mode parameter outlined earlier, you could add the following in the control panel:

ajax_load = python: request.form.get('ajax_load')
mode = string: test

The right hand side is a TALES expression. It must evaluate to a string, integer, float, boolean or None: lists, dicts and objects are not supported. python:, string: and path expressions work as they do in Zope Page Templates.

The following variables are available when constructing these TALES expressions:

context
The context of the current request, usually a content object.

request
The current request.

portal
The portal root object.

context_state
The @@plone_context_state view, from which you can look up additional values such as the context's URL or default view.

portal_state
The @@plone_portal_state view, form which you can look up additional values such as the navigation root URL or whether or not the current user is logged in.

See plone.app.layout for details about the @@plone_context_state and @@plone_portal_state views.

Theme parameters are usually integral to a theme, and will therefore be set based on a theme's manifest when a theme is imported or enabled. This is done using the [theme:parameters] section in the manifest.cfg file. For example:

[theme]
title = My theme
description = A test theme

[theme:parameters]
ajax_load = python: request.form.get('ajax_load')
mode = string: test

Theme debugging

When Zope is in development mode (e.g. running in the foreground in a console with bin/instance fg), the theme will be re-compiled on each request. In non-development mode, it is compiled once when first accessed, and then only re-compiled the control panel values are changed.

Also, in development mode, it is possible to temporarily disable the theme by appending a query string parameter diazo.off=1. For example:

http://localhost:8080/Plone/some-page?diazo.off=1

Finally, you can get an overlay containing your rules, annotated with how many times the conditions matched both the theme and the document. Green means the condition matched, red means it didn't. The entire rule tag will be green (i.e. it had an effect) so long as all conditions within are green.

To enable this, append diazo.debug=1. For example:

http://localhost:8080/Plone/some-page?diazo.debug=1

The parameter is ignored in non-development mode.

Commonly used rules

The following recipes illustrate rules commonly used in building Plone themes:

To copy the page title:

To copy the `` tag (necessary for Plone's links to work):

If there is no `` tag in the theme, you can do:

To drop all styles and JavaScript resources from the theme and copy them from Plone's portal_css tool instead:

To copy Plone's JavaScript resources:

To copy the class of the `` tag (necessary for certain Plone JavaScript functions and styles to work properly):

Advanced: Using portal_css to manage your CSS

Plone's "resource registries", including the portal_css tool, can be used to manage CSS stylesheets. This offers several advantages over simply linking to your stylesheets in the template, such as:

• Detailed control over the ordering of stylesheets
• Merging of stylesheets to reduce the number of downloads required to render your page
• On-the-fly stylesheet compression (e.g. whitespace removal)
• The ability to include or exclude a stylesheet based on an expression

It is usually desirable (and sometimes completely necessary) to leave the theme file untouched, but you can still use portal_css to manage your stylesheets. The trick is to:

• Register your theme's styles with Plone's portal_css tool (this is normally best done when you ship a theme in a Python package - there is currently no way to automate this for a theme imported from a Zip file or created through the web)
• Drop the theme's styles with a rule, and then
• Include all styles from Plone

For example, you could add the following rules:

The use of an "or" expression for the content in the after /> rule means that the relative ordering of link and style elements is maintained.

To register stylesheets upon product installation using GenericSetup, use the cssregistry.xml import step in your GenericSetup profiles/default directory:

There is one important caveat, however. Your stylesheet may include relative URL references of the following form:

background-image: url(../images/bg.jpg);

If your stylesheet lives in a resource directory (e.g. it is registered in portal_css with the id ++theme++my.theme/css/styles.css), this will work fine so long as the registry (and Zope) is in debug mode. The relative URL will be resolved by the browser to ++theme++my.theme/images/bg.jpg.

However, you may find that the relative URL breaks when the registry is put into production mode. This is because resource merging also changes the URL of the stylesheet to be something like:

/plone-site/portal_css/Suburst+Theme/merged-cachekey-1234.css

To correct for this, you must set the applyPrefix flag to true when installing your CSS resource using cssregistry.xml. There is a corresponding flag in the portal_css user interface.

It is sometimes useful to show some of Plone's CSS in the styled site. You can achieve this by using an Diazo rule or similar to copy the CSS from Plone's generated into the theme. You can use the portal_css tool to turn off the style sheets you do not want.

However, if you also want the site to be usable in non-themed mode (e.g. on a separate URL), you may want to have a larger set of styles enabled when Diazo is not used. To make this easier, you can use the following expressions as conditions in the portal_css tool (and portal_javascripts if relevant), in portal_actions, in page templates, and other places that use TAL expression syntax:

request/HTTP_X_THEME_ENABLED | nothing

This expression will return True if Diazo is currently enabled, in which case an HTTP header "X-Theme-Enabled" will be set.

If you later deploy the theme to a fronting web server such as nginx, you can set the same request header there to get the same effect, even if plone.app.theming is uninstalled.

Use:

not: request/HTTP_X_THEME_ENABLED | nothing

to 'hide' a style sheet from the themed site.

Advanced: Disable diazo transformation by setting the X-Theme-Disabled header

The diazo transformation is not applied if a response header X-Theme-Disabled is set.

In a browser view, the header can be set by using this instruction:

self.request.response.setHeader('X-Theme-Disabled', '1')

This is a complete example:

class NoDiazoView(BrowserView):

    def __call__(self):
        self.request.response.setHeader('X-Theme-Disabled', '1')
        return super(NoDiazoView).__call__()

Changelog

5.0.10 (2024-09-05)

Internal:

• Minor optimization to disable Diazo theming via X-Theme-Disabled a tick earlier. [thet] (#244)

5.0.9 (2024-05-06)

Bug fixes:

• Fix an issue with unicode characters happening with lxml 5 [ale-rt] (#238)

5.0.8 (2024-04-22)

Bug fixes:

• Traverse to theme resources from the navigation root again. Only when this gives an Unauthorized, try it on the portal as a fall back. This fixes other use cases of traversing to absolute urls in a theme. [maurits] (#236)

5.0.7 (2024-01-18)

Bug fixes:

• Traverse to theme resources from the portal. Fix broken theme when rendering accessible content contained in an inaccessible navigation-root. Fixes #142 [pbauer] (#142)

5.0.6 (2023-12-14)

Bug fixes:

• Fix AttributeError in custom.css: "module 'wsgiref' has no attribute 'handlers'". [maurits] (#230)

5.0.5 (2023-10-07)

Internal:

• Update configuration files. [plone devs] (cfffba8c)

5.0.4 (2023-06-22)

Bug fixes:

• Unify default values for translations [erral] (#223)

5.0.3 (2023-04-06)

Bug fixes:

• Fix theme for pat-code-editor. [petschki] (#219)

5.0.2 (2023-03-22)

Bug fixes:

• Fixes circular dependency on ZCML level to `Products.CMFPlone`: Move permission id=`plone.app.controlpanel.Themes` title=`Plone Site Setup: Themes` to this package. [jensens] (permission-move)

Internal:

• Update configuration files. [plone devs] (80cf330f)

5.0.1 (2023-03-14)

Bug fixes:

• Import more from plone.base. Removed compatibility code for Python 2 and Zope 4. [maurits] (#1)
• Bugfix: If there is no rules.xml given in a theme, abort transform early. Otherwise, given an open file is given as iterable, the read buffer pointer is empty after this function, but None returned. The new way the read buffer pointer is not touched. [jensens, toalba] (#216)

5.0.0 (2022-12-02)

Bug fixes:

• Final release for Plone 6.0.0. (#600)

5.0.0b2 (2022-10-11)

Bug fixes:

• Fix for tinymce-styles-css when copying theme. [petschki] (#214)

5.0.0b1 (2022-08-31)

Bug fixes:

• The action buttons in the theming control panel have been improved [rohnsha0] (#212)

5.0.0a5 (2022-04-04)

New features:

• Deactivate copy button and modal in theming control panel. [MrTango] (#205)
• Load barceloneta css in theming control panel to have it styled. [MrTango] (#205)
• Remove all thememapper functionality from theming control panel, including Inspect/Modify theme and the Preview. [maurits] (#205)
• Use pat-code-editor for custom-css field. [MrTango] (#205)

5.0.0a4 (2021-11-23)

Bug fixes:

• Add missing i18n:translate tags [erral] (#204)

5.0.0a3 (2021-10-13)

Bug fixes:

• Use HTML5 meta charset. [thet] (#203)

5.0.0a2 (2021-09-15)

Bug fixes:

• Fix unclosed file when reading manifest.cfg [petschki] (#199)
• Remove cyclic dependency with Products.CMFPlone [sneridagh] (#201)

5.0.0a1 (2021-07-26)

Breaking changes:

• Add bootstrap icon from resolver from Plone 6. [petschki, agitator] (#194)

Bug fixes:

• Avoid Server Side Request Forgery via lxml parser. Taken over from PloneHotfix20210518. [maurits] (#3274)

4.1.6 (2020-11-17)

Bug fixes:

• For increased security, fail when trying file protocol access in diazo rules. Also do not resolve entities, and remove processing instructions. [maurits] (#3209)

4.1.5 (2020-09-26)

Bug fixes:

• Fixed WrongContainedType for hostnameBlackList on Zope 5. See also issue 183. [maurits] (#183)
• Fixed deprecation warning for ConfigParser.readfp. [maurits] (#3130)

4.1.4 (2020-08-14)

Bug fixes:

• Fix a missing import [ale-rt] (#188)

4.1.3 (2020-07-30)

Bug fixes:

• Fixes #187: Invalid dependency on plone.app.caching [jensens] (#187)
• Cleanup: Remove meanwhile unused test fixture code referring to plone.app.caching. Removed class and fixtures: ThemingWithCaching, THEMINGWITHCACHING_FIXTURE, THEMINGWITHCACHING_TESTING. Those were nowhere used active in Plone nor outside in Github. [jensens] (#188)

4.1.2 (2020-07-01)

Bug fixes:

• Internationalize the Custom CSS placeholder. This fixes

  [vincentfretin] (#186)

4.1.1 (2020-06-24)

Bug fixes:

• Fix i18n of new messages related to new Custom CSS feature. [vincentfretin] (#185)

4.1.0 (2020-06-16)

New features:

• Insert diazo bundle without rules. [santonelli] (#176)
• Add custom CSS settings and view to theming control panel. Depends on [MrTango] (#178)

Bug fixes:

• Fix error on Python 3 with nonascii subrequest. The subrequest would succeed, but the non-ascii would be ugly. Fixes issue 3069 and issue 162. [maurits] (#162)
• Make it possible to preview themes TTW again. [petri] (#173)
• Fix hostnameBlacklist (Theming ControlPanel) in Py3. [MrTango] (#179)
• Fix various WrongType exceptions when saving the control panel. This was introduced by the processInputs change in version 4.0.5. See issue 183. [maurits] (#183)

4.0.6 (2020-04-20)

Bug fixes:

• Minor packaging updates. (#1)

4.0.5 (2020-03-13)

Bug fixes:

• Do not call processInputs. It is not needed since Zope 4, and not existing in Zope 5. [maurits] (#171)

4.0.4 (2019-12-11)

Bug fixes:

• Fix creating a new theme ttw in py2 with Zope 4.1.3. [pbauer] (#166)

4.0.3 (2019-10-12)

Bug fixes:

• Load zcml of plone.resource for our use of the plone:static directive. [maurits] (#2952)

4.0.2 (2019-09-13)

Bug fixes:

• Fixed Python3 TypeError: 'filter' object is not subscriptable. This happened when overriding a filesystem theme with a TTW version [fredvd] (#160)

4.0.1 (2019-02-14)

Bug fixes:

• Fix skinname-encoding in py3 (fixes ) [pbauer] (#2748)

4.0.0 (2019-02-13)

Breaking changes:

• Factor out all static resources into plone.staticresources as part of PLIP
  1. [thet, sunew] (#149)

Bug fixes:

• a11y: Added role attribute for portalMessage [nzambello] (#151)
• Fixed DeprecationWarning about SafeConfigParser class on Python 3. [maurits] (#152)
• Fixed ResourceWarnings for unclosed files in tests. [maurits] (#154)
• Fixed "RuntimeError: dictionary changed size during iteration" [jensens] (#156)

3.0.1 (2018-12-11)

Breaking changes:

• Remove five.globalrequest dependency. It has been deprecated upstream (Zope 4). [gforcada]

3.0.0 (2018-11-02)

New features:

• Recompiled resource bundles with latest mockup. [sunew]

Bug fixes:

• Explicit load permissions for controlpanel. [jensens]
• Fix tests for merged plone.login. [jensens]
• More Python 3 fixes [ale-rt, pbauer, davisagli]

2.0.3 (2018-04-04)

Bug fixes:

• Added a failing (5.1) test for fileuploads in the theme editor that breaks when plone.rest is installed. Fix is in [djay]

2.0.2 (2018-02-04)

Bug fixes:

• remove mention of non-existent Example theme [tkimnguyen]
• Prepare for Python 2 / 3 compatibility [pbauer, ale-rt]

2.0.1 (2017-07-03)

Bug fixes:

• Remove unittest2 dependency [kakshay21]

2.0 (2017-05-24)

Breaking changes:

• Let the pattern configuration of the thememapper be in JSON format. Fixes problems of thememapper working together with latest patternslib (2.1.0). [thet]

Bug fixes:

• Fix thememapper pattern handling of buttons (via mockup update). Update thememapper bundle. [thet]

1.3.6 (2017-03-28)

Bug fixes:

• Reduce log level of ThemingPolicy cache to 'debug'. [jensens]

1.3.5 (2017-02-12)

Bug fixes:

• Fix imports from Globals that was removed in Zope4 [pbauer]
• No longer patch Control Panel internals, as it was removed in Zope4 [MatthewWilkes]
• reST syntax, styleguide, wording and line length of the docs [svx]

1.3.4 (2016-12-30)

Bug fixes:

• Make diazo.debug work again when DIAZO_ALWAYS_CACHE_RULES is set. [ale-rt]

1.3.3 (2016-12-02)

Bug fixes:

• Remove roman monkey patch. [gforcada]

1.3.2 (2016-09-23)

New features:

• Add Update -button for theming control panel making it possible to reload modified theme manifest without deactivating theme at first. [datakurre]

1.3.1 (2016-09-07)

Fixes:

• Enable unload protection by using pattern class pat-formunloadalert instead enableUnloadProtection. [thet]
• Small fix in documentation [staeff]
• Fix issue where theming control panel errored when a packaged theme was overridden with a global resource directory theme [datakurre]

1.3.0 (2016-06-07)

New:

• Control theme compilation in development mode through the environment variable DIAZO_ALWAYS_CACHE_RULES [ale-rt]

Fixes:

• Small fixes to documentation [ale-rt]

1.2.19 (2016-03-31)

New:

• For the theming controlpanel, change base URLs from portal URL to what getSite returns, but don't change the controlpanels context binding. This allows for more flexibility when configuring it to be allowed on a sub site with a local registry. [thet]

1.2.18 (2016-03-03)

Fixes:

• Fixed html validation: element nav does not need a role attribute. [maurits]
• Handle potential scenarios where wrong theme would show selected in the theming control panel [vangheem]

1.2.17 (2016-02-11)

New:

• Documented how to disable diazo transform by setting the X-Theme-Disabled header. [ale-rt]

Fixes:

• Rebuild resources so they work with latest mockup/patternslib integration changes. [vangheem]
• Removed github dependencies in thememapper. [Gagaro]

1.2.16 (2015-11-26)

Fixes:

• Updated Site Setup link in all control panels. Fixes

  [davilima6]

1.2.15 (2015-10-28)

Fixes:

• Do not fail in isThemeEnabled when we have no settings, for example when migrating from Plone 3 to Plone 5, but maybe also in other cases. [maurits]
• Fixed Unicode Encode Error when to copy into multi-byte title / description [terapyon]

1.2.14 (2015-09-27)

• Fix i18n in mapper.pt [vincentfretin]

1.2.13 (2015-09-20)

• Pull mark_special_links, external_links_open_new_window values from configuration registry. [esteele]
• Fix visual glitch on Safari [davilima6]
• Show active theme at the top of the theme list. Fixes [tmassman]

1.2.12 (2015-09-15)

• Remove bundled twitter bootstrap theme 'example'. Fixes [pbauer]
• Remove duplicate type attribute for theming control panel delete modal. [esteele]

1.2.11 (2015-09-11)

• rewrite manifest from copied theme with relative paths also [vangheem]

1.2.10 (2015-09-08)

• theme mapper fixes for odd behavior in save files at times [swartz]

1.2.9 (2015-08-22)

• Build thememapper resources. [vangheem]
• Added cache invalidation option. [swartz]

1.2.8 (2015-08-20)

• change link from plone.org to plone.com. [tkimnguyen]
• fix toolbar on control panel [vangheem]
• fix less building [obct537]
• Fixed copy modal for themes with a dot in the name. [Gagaro]

1.2.7 (2015-07-18)

• Provide better styling to theming control panel, less build, finish implementation [obct537]
• make sure when copying themes that you try to modify the base urls to match the new theme are all the manifest.cfg settings [vangheem]
• implement switchable theming policy API, re-implement theme caching [gyst]
• fixed configuration of copied theme [vmaksymiv]
• implemented upload for theme manager [schwartz]
• Change the category of the configlet to 'plone-general'. [sneridagh]

1.2.6 (2015-06-05)

• removed irrelevant theme renaming code [schwartz]
• Filesystem themes are now correctly overridden. TTW themes can no longer be overridden [schwartz]
• re-added manifest check [schwartz]
• Fixed broken getTheme method [schwartz]
• Minor ReStructuredText fixes for documentation. [maurits]

1.2.5 (2015-05-13)

• Fix RestructuredText representation on PyPI by bringing back a few example lines in the manifest. [maurits]

1.2.4 (2015-05-12)

• Add setting for tinymce automatically detected styles [vangheem]

1.2.3 (2015-05-04)

• fix AttributeError: 'NoneType' object has no attribute 'getroottree' when the result is not html / is empty. [sunew]
• make control panel usable again. Fixed problem where skins control panel is no longer present. [vangheem]
• unified different getTheme functions. [jensens]
• pep8ified, housekeeping, cleanup [jensens]
• Specify i18n:domain in controlpanel.pt. [vincentfretin]
• pat-modal pattern has been renamed to pat-plone-modal [jcbrand]
• Fix load pluginSettings for the enabled theme before calling plugins for onEnabled and call onEnabled plugins with correct parameters [datakurre]

1.2.2 (2015-03-22)

• Patch the ZMI only for available ZMI pages. [thet]
• Change deprecated import of zope.site.hooks.getSite to zope.component.hooks.getSite. [thet]
• Add an error log if the subrequest failed (probably a relative xi:include) instead of silently returning None (and so having a xi:include returning nothing). [vincentfretin]
• Fix transform to not affect the result when theming is disabled [datakurre]
• Integrate thememapper mockup pattern and fix theming control panel to be more usable [ebrehault]

1.2.1 (2014-10-23)

• Remove DL's from portal message in templates. [khink]
• Fix "Insufficient Privileges" for "Site Administrators" on the control panel. [@rpatterson]
• Add IThemeAppliedEvent [vangheem]
• Put themes in a separate zcml file to be able to exclude them [laulaz]
• #14107 bot requests like /widget/oauth_login/info.txt causes problems finding correct context with plone.app.theming [anthonygerrard]
• Added support for ++theme++ to traverse to the contents of the current activated theme. [bosim]

1.2.0 (2014-03-02)

• Disable theming for manage_shutdown view. [davisagli]
• Fix reference to theme error template [afrepues]
• Add "Test Styles" button in control panel to expose, test_rendering template. [runyaga]

1.1.1 (2013-05-23)

• Fixed i18n issues. [thomasdesvenain]
• Fixed i18n issues. [jianaijun]
• This fixed UnicodeDecodeError when Theme Title is Non-ASCII in the manifest.cfg file. [jianaijun]

1.1 (2013-04-06)

• Fixed i18n issues. [vincentfretin]
• Make the template theme do what it claims to do: copy styles as well as scripts. [smcmahon]
• Change the label and description for the example theme to supply useful information. [smcmahon]
• Upgrades from 1.0 get the combined "Theming" control panel that was added in 1.1a1. [danjacka]

1.1b2 (2013-01-01)

• Ensure host blacklist utilises SERVER_URL to correctly determine hostname for sites hosted as sub-folders at any depth. [davidjb]
• Add test about plone.app.theming / plone.app.caching integration when using GZIP compression for anonymous (see ticket 12038). [ebrehault]

1.1b1 (2012-10-16)

• Add diazo.debug option, route all error_log output through this so debugging can be displayed [lentinj]
• Make example Bootstrap-based theme use the HTML5 DOCTYPE. [danjacka]
• Demote ZMI patch log message to debug level. [hannosch]
• Upgrade to ACE 1.0 via plone.resourceeditor [optilude]
• Put quotes around jQuery attribute selector values to appease jQuery 1.7.2. [danjacka]

1.1a2 (2012-08-30)

• Protect the control panel with a specific permission so it can be delegated. [davisagli]
• Advise defining ajax_load as request.form.get('ajax_load') in manifest.cfg. For instance, the login_form has an hidden empty ajax_load input, which would give an unthemed page after submitting the form. [maurits]
• Change theme editor page templates to use main_template rather than prefs_main_template to avoid inserting CSS and JavaScript too early under plonetheme.classic. [danjacka]

1.1a1 (2012-08-08)

• Replace the stock "Themes" control panel with a renamed "Theming" control panel, which incorporates the former's settings under its "Advanced" tab. [optilude]
• Add a full in-Plone theme authoring environment [optilude, vangheem]
• Update IBeforeTraverseEvent import to zope.traversing. [hannosch]
• On tab "Manage themes", change table header to better describe what's actually listed. [kleist]

1.0 (2012-04-15)

• Prevent AttributeError when getRequest returns None. [maurits]
• Calculate subrequests against navigation root rather than portal. [elro]
• Supply closest context found for 404 pages. [elro]
• Lookup portal state with correct context. [elro]

1.0b9 - 2011-11-02

• Patch App.Management.Navigation to disable theming of ZMI pages. [elro]

1.0b8 - 2011-07-04

• Evaluate theme parameters regardless of whether there is a valid context or not (e.g. when templating a 404 page). [lentinj]

1.0b7 - 2011-06-12

• Moved the views and overrides plugins out into a separate package plone.app.themingplugins. If you want to use those features, you need to install that package in your buildout. Themes attempting to register views or overrides in environments where plone.app.themingplugins is not installed will install, but views and overrides will not take effect. [optilude]

1.0b6 - 2011-06-08

• Support for setting arbitrary Doctypes. [elro]
• Upgrade step to update plone.app.registry configuration. [elro]
• Fixed plugin initialization when applying a theme. [maurits]
• Query the resource directory using the 'currentTheme' name instead of the Theme object (updating the control panel was broken). [maurits]
• Fix zip import (plugin initialization was broken.) [elro]

1.0b5 - 2011-05-29

• Make sure the control panel is never themed, by setting the X-Theme-Disabled response header. [optilude]
• Add support for registering new views from Zope Page Templates and overriding existing templates. See README for more details. [optilude]

1.0b4 - 2011-05-24

• Add support for X-Theme-Disabled response header. [elro]
• Make "Replace existing theme" checkbox default to off. [elro]
• Fix control panel to correctly display a newly uploaded theme. [elro]
• Fix zip import to work correctly when no manifest is supplied. [elro]

1.0b3 - 2011-05-23

• Show theme name along with title in control panel. [elro]

1.0b2 - 2011-05-16

• Encode internally resolved documents to support non-ascii characters correctly. [elro]
• Fix control panel to use theme name not id. [optilude]

1.0b1 - 2011-04-22

• Wrap internal subrequests for css or js in style or script tags to facilitate inline includes. [elro]
• Add theme.xml import step (see README). [optilude]
• Add support for [theme:parameters] section in manifest.cfg, which can be used to set parameters and the corresponding TALES expressions to calculate them. [optilude]
• Add support for parameter expressions based on TALES expressions [optilude]
• Use plone.subrequest 1.6 features to work with IStreamIterator from plone.resource. [elro]
• Depend on Products.CMFPlone instead of Plone. [elro]
• Added support for uploading themes as Zip archives. [optilude]
• Added theme off switch: Add a query string parameter diazo.off=1 to a request whilst Zope is in development mode to turn off the theme. [optilude]
• Removed 'theme' and alternative themes support: Themes should be referenced using the `` directive in the Diazo rules file. [optilude]
• Removed 'domains' support: This can be handled with the rules file syntax by using the host parameter. [optilude]
• Removed 'notheme' support: This can be handled within the rules file syntax by using the path parameter. [optilude]
• Added path and host as parameters to the Diazo rules file. These can now be used as conditional expressions. [optilude]
• Removed dependency on XDV in favour of dependency on Diazo (which is the new name for XDV). [optilude]
• Forked from collective.xdv 1.0rc11. [optilude]