History of the template language #

The template language is older than most of the code around it. This page tells its story from what the repository itself records: the git history, the changelogs in doc/changelogs/, the feature notes in doc/eng-us/features/ and comments in the source. Nothing here comes from memory or from outside sources.

Contents #

1. Where it came from
2. The record in the repository
3. From process cache to compiler (2003)
4. The improved syntax (2005, version 3.6)
5. What the older style looks like today
6. Exponential carries it on
7. Related pages

Where it came from #

Exponential continues the code base that was published for many years as eZ Publish. That product was discontinued by its creator after almost 18 years; the copyright notice still names both owners of the code: "Copyright (C) 1998 - 2026 Exponential Foundation and 7x" and "Copyright (C) eZ Systems AS", the line at the top of lib/eztemplate/classes/eztemplate.php. The template library has been part of the code base for its whole recorded history, and 7x has carried it forward since taking over the project in 2023 (Who is 7x?).

The record in the repository #

From process cache to compiler (2003) #

The template compiler started under another name. The commit of 14 May 2003 (88c1f9460c) "Renamed the process cache system to template compiling which is a better name", and the 3.1 changelog notes "Finished the template compiling system, it will now generate PHP template files that can be properly executed". Two days later (4fe8ef4f1c) node transformation support was added for let, default and section, the hook that still lets a function write its own PHP code (templateNodeTransformation()).

The 3.4 changelog then reports "Implemented template compilation for almost all template operators and functions", added parameters to eztc.php (the command that compiles templates ahead of time) and the subtree_expiry option of {cache-block}. The settings that control all of this are still in settings/site.ini [TemplateSettings]: TemplateCompile, TemplateOptimization, TemplateCache, DevelopmentMode.

The improved syntax (2005, version 3.6) #

The biggest change to the language itself came with commit 7460c738b2 of 18 March 2005: "Initial implementation of the new template functions: {def}, {undef}, {if}, {elseif}, {else}, {while}, {do}, {for}, {foreach}, {break}, {continue}, {skip}". Its design note is still in the repository, doc/eng-us/features/3.6/improved_template_syntax.txt. Its stated incentive: "To make template syntax clearer and more similar to syntax of widespread procedural programming languages."

What it changed:

• The dollar sign everywhere, also in assignments: {set $i=10}. "Old-style assignments without "$" shall work."
• def and undef instead of {let}...{/let} blocks, because a block "makes harder to read tpl file and move code within it". A variable made with {def} lives until the end of its file.
• if, while, do, for and foreach as "much simplier to understand and use by developers than the allmighty {section} function".
• break, continue, skip and delimiter for every loop.

The note also records what foreach deliberately does not do: it does not loop over the characters of a string or a number range (use for), and it has no proxy iterator ($item.index); section keeps those. The 3.6 changelog carries the first bug reports against "the new template syntax" (#6629) and "the new template loop" (the {delimiter} fix), and the 3.8 changelog the fix that {undef} "was able to destroy template variables created with not {def}".

What the older style looks like today #

Both styles still run side by side. The same list, written the old way and the new way, rendered on a development installation:

{* the older style: let ... /let and section *}
{let items=array( 'red', 'green', 'blue' )}
old: {section name=Colors loop=$items}{$Colors:item}{delimiter}, {/delimiter}{/section}
{/let}
{* the style introduced with def and foreach *}
{def $items = array( 'red', 'green', 'blue' )}
new: {foreach $items as $item}{$item}{delimiter}, {/delimiter}{/foreach}
{undef $items}

Output:

old: red, green, bluenew: red, green, blue

Other traces of the history in today's code:

• lib/eztemplate/classes/eztemplateautoload.php still registers array_prepend, array_append and array_merge, marked // DEPRECATED/OBSOLETE, next to their replacements prepend, append and merge.
• let and default are still registered (eZTemplateSetFunction), as is section with its section-else, section-exclude and section-include children (Sections versus foreach).
• The parser still accepts set, let and default parameters without a dollar sign, and treats name and scope written without one as the namespace and scope of the function (parseSetFunction() in lib/eztemplate/classes/eztemplatemultipassparser.php).

Exponential carries it on #

Under 7x the language is maintained as part of the kernel and extended where it helps current sites, always keeping the templates of existing designs working. Examples of what the 6.0 line added in the template engine and around it: the ShowTemplatePathComments setting that wraps each rendered template in HTML comments naming its file (eZTemplate::showTemplatePathComments()), a warning written once per operator and parameter for a missing default value (eZTemplate), and the csp_nonce and exp_environment operators of the kernel. The changelog of each release lists the changes: doc/changelogs.

Related pages #

• Previous: What the template language is
• Next: Smarty and the template language side by side
• Sections versus foreach
• Section (legacy) for converting old templates
• Who is 7x?
• Free documentation: this page is free to copy, translate and improve under the GNU FDL 1.3.