Dynamic Template Module
- Mark Stephens (mark at silverstripe dot com)
- SilverStripe 3.0 or newer
- Alpha state for SilverStripe 3
- Front end execution of dynamic templates working but requires more rigourous testing
- CMS bugs exist, especially with automatic refreshing after adding or uploading
This module lets you alter the presentation of pages on your site flexibly and dynamically. Example applications include:
- pages (e.g. home or landing pages) whose design may change frequently
- pages where promotional or informational changes are required for a limited period of time
- for designing variations of page design for use with the A/B testing module.
The module provides functionality aimed at users with a level of competency in HTML/CSS, including but not limited to designers and developers.
Key features include:
- a CMS interface for creating, editing, previewing and applying dynamic templates to pages.
- import/export of dynamic templates, allowing the development of dynamic templates in a development environment, and shipped to the production environment.
- Rapid development and application of templates to pages
- Lowers the barrier of entry to working with SilverStripe templates
- Code deployments are not required for changes in dynamic templates
- Fits in with the page publishing mechanism so changes can be viewed in draft, and used in conjunction with features such as embargo/expiry in cmsworkflow that automate the publishing/unpublishing of pages.
Different dynamic templates can apply to draft vs. live versions of a page, and hence a promotional design can be tested, and switched live when ready.
Simply add the module to the top level of your SilverStripe installation and perform a dev/build. A new page type will be created called DynamicTemplatePage, which you can subclass for pages that require dynamic behaviour.
The module adds a new section "Dynamic Templates" to the CMS. This shows the dynamic templates currently in the system, and supports the following operations:
- Create an empty dynamic template
- Create a dynamic template from the theme
- Delete a dynamic template
- Upload a dynamic template
- Manage a dynamic template
Dynamic Template Editing
The editor for dynamic templates has 3 tabs:
- Properties - lets you edit the name of the template, as well as showing the URL that assets for the template are relative to.
- Files - the meat of the interface, this lets you add, edit, link and remove files.
Files in a Dynamic Template
A dynamic template's behaviour is determined by the files you add to it. Files are automatically organised by their type, which can include:
- SilverStripe template files (.ss) - these are put in a "templates" folder
- CSS files (.css) - these are put in a "css" folder
- Images (.png, .jpg, .jpeg, .gif) - these are put in an images folder
When a dynamic template is applied to a page, it applies the following logic:
- All files (if any) in the "css" folder are added to the page, using Requirements::css()
- Template files are used to override the default template files for the page. There can be at most one "main" template and at most one "layout" template, which override the corresponding template for the page. Templates that are present in the dynamic template but which are not marked "main" or "Layout" are ignored when rendering.
- Nothing is done with images; these are expected to be referenced by either the templates or the CSS in the dynamic template
Files in a dynamic template can either exist only in the template, or can be linked from the theme. When they exist in the template only, you can edit them. If you delete the template, such files are deleted. You can either create files manually, or copy them from the theme and then modify them to suit.
When files are linked, they remain physically located in the theme folder, and cannot be edited in the CMS (but can be viewed for reference)
A common pattern for overriding pages is to link the main Page.ss file from the theme, and copy the closest layout template from the theme into the dynamic template, and edit it there. This still provides consistency with the outer page container, while letting you alter the layout of the page.
Internal Representation of Dynamic Templates
A dynamic template is a collection of files in a small directory structure. These sit under the assets folder in the site, which is typically the only writable folder in the project structure.
The top level of a template folder will typically contain:
- A file called
MANIFESTwhich defines the assets present in the template and how they are applied to the page when rendered.
A zip file containing a template can either have the folders and MANIFEST directly at the top level of the ZIP file, or these may be contained in a single folder at the top level of the ZIP. (Absolute paths should not be used in the zip file).
This is a YAML file that defines what is in the template and how it behaves when applied to a DynamicTemplatePage derivative.
The following is a simple example of a MANIFEST file:
At the top level are the actions available in the controller. Typically
this is just "index", but there may be others if the controller understands
mypage/profile has an action "profile", which can have distinct
mypage/edit, which has an action "edit".
mypage has an action
The templates for an action consist of label/value pair. The label (e.g. "main:" above) is understood by SilverStripes template renderer, and can be either "main", "Layout" or "Content", with the meanings being consistent with the renderer's usage. The value part, as above, is the name of a .ss file within the templates directory. (If there are further folders, the .ss files may be prefixed with these). When a page is rendered with a dynamic template, the full path names are automatically determined and passed into the viewer.
Note: a current limitation is that you can't specified a template for Layout, and have the viewer automatically determine the main template. This will be resolved as soon as possible, for maximum flexbility and re-use.
CSS declarations in the manifest file can simply list the name of a file in the css directory, or can also include the screen or print media directives. (CSS files used in rendering a dynamic content page are added to the page using Requirements::css() in the controller's init() function. The pathname will be expanded automatically to the path relative to the base URL of the site)
When a MANIFEST file is provided, it can include as its first definition an action called "metadata" which can define extra properties for the template.
metadata: classes: PageA,PageB index: templates: main: BasePage.ss
There is only one meta-data property at present, which is the "classes" property. It defines a list of classes that the template applies to. The user cannot select a template for a page unless that page is or descends from one of the classes listed. This prevents a template designed for one page layout from being applied accidentally to the wrong page type.
- <% include %> tags can be used to include a file from the theme, but not from within the dynamic template itself.
- References to resources such as images in the CSS or template markup have to rely on knowing where the containing dynamic template is installed on assets, so there is coupling between the template and the configuration option to determine where templates reside within assets. It might be useful to have some notation that can be used in CSS and SS files that indicate that an image is in the template, and automatically translate the path.
- Actions other than index cannot currently be edited within the CMS view.