Best way to create a "template interpreter" in PHP - php

I'm hosting a multi area solution written in PHP, and each customer has its own template in some HTML files. Now I want these users to be able to use some chunks of dynamic content, but they can't be able to use PHP. I thought something like:
In the HTML file, if I put this:
<ul>[menu-list]</ul>
Will output something like:
<ul><li><a[...]>Home</a></li><li><a[...]>About</a></li>[...]</ul>
Is there any better way of doing it than keep parsing and caching files via file_get_contents() and preg_match_all()?
I want to create about 20 entries like [menu-list], and parsing every file for all of them seems quite expensive to me.
I'd appreciate any suggestion. =D

Perhaps you should consider using a template compiler instead of a template interpreter. That is, instead of each time the page is loaded doing this whole replacement procedure you could simply perform the replacement after the template has been modified. During template editing the cost should be negligible. To implement this compilation you could choose to "compile" in some breadcrumbs so you can go backwards, or you can simply save the original template files for later editing.
Alternatively, you could consider using PHP variable naming conventions and running your templates through an eval, but this poses a number of other issues (like security threats) and doesn't come highly recommended.

Why can't you use Smarty and friends? I would not want to write what you suggest myself.

Related

how to isolate the style (css+html) from php

how can i isolate the style (css+html) from php, like put in the php file just some lines including by it the whole style or theme.
ex:
echo
eval_template("header") .
eval_template("body") .
eval_template("footer")
So in future i can change the whole style without touch the php files
any idea ?
there are many ways how you could do this...
Here's a tutorial on templating in plain PHP
http://www.phpro.org/tutorials/Introduction-to-PHP-templating.html
You can also take a look at the many template engines out there.
twig is one of them: http://twig.sensiolabs.org/
Personally, I enjoy to do it manually.
PHP should not return both css and html code, or even better, it shoukd not return client-side code at all but rather dependencies to specific parts. You never want to modify a file that contains a lot of different things.
To separate css+html from the php code, what I usually do is a hierarchy done with include("..."); and include_once("..."). For example : include_once("header.php") > include("menu.php") > html semantic with css classes correctly initialized according to current context.
Then you import your css / js external scripts in header.php so that you never have to modify the whole thing unless everything changes or if you have a complete feature to add to the website. Same is possible for every sections of the website.
Hope this helps, for me it is incredibly reducing debug-time since everything important has to be done only once, then at the top of it, you can seperate as you wish.
There are a lot of template engines you can use to do that, i prefer use twig, that is integrated with symfony2 framework.
Twig is wonderful because is very easy to use and very flexible, you can use inheritance to create a common layout which can be extended and overwriten in some some part using special tags. This is a guide i've find on Symfony website but is very usefull to understand the logic behind twig: http://symfony.com/doc/current/book/templating.html

Bespoke PHP Templating Engine

As a small part of a university project I'm working on (custom MVC based project management system), I need to develop a template engine. I don't wish to use an off the self system such as Smarty because I've written every other part of the project myself and don't want to go back on that now.
Anyway, I've managed to code something simple so far, I have a class, create an instance of it, add some data to the instance, then pass in a template file. The file has a series of tags like {this} when then get replaced with the data. Simple.
The issue I'm having is when it comes to looping things - i.e. a table of users or a list of categories. At the moment I have a template file for the page (users.html) which contains the opening and closing tags, with a template tag between them called {users}. I then have another template file (users-detail.html) which displays a table row with the user info in. I'm creating a new instance of the users-detail.html template, adding the data, parsing it, then placing the output (string of HTML) into an array. I then loop this array, attach all the strings together, then assign this to the {users} tag in the users.html template file.
As you can probably tell from that explanation it is a bit of a bodge, and there are probably better methods out there for doing what I'm trying to achieve. Ideally I want to avoid using PHP in the template files if possible, and I often need to have multiple loops within one template file.
If anyone has any tips / advice on how I can achieve this, or any tutorials I could follow to get some inspiration that would be much appreciated.
Thanks in advance.
I've seen that approach before (including another template for the insides of loops). I used to work on an old version of vbulletin which does (or did) this. It makes things annoyingly complicated because you can't just add a loop to a template - without setting up a whole new template for each layer of looping.
I'd advise you instead to go along the route of Smarty.
Classically, this statement:
I don't wish to use an off the self system such as Smarty because I've written every other part of the project myself and don't want to go back on that now.
... indicates you really should just be using Smarty. In the real world that would be a poor justification for re-implementing something yourself. But I am like you, and I understand that you want to implement something yourself (because you want to learn, you find it fun, you are a perfectionist, etc). As long as you do it on your own time and it's a personal project, go for it.
It would be worth studying Smarty to see how it works (not just the syntax but how it compiles templates, stores the compiled version etc). Are you comfortable writing a tokeniser/parser in PHP which can compile your template language and output PHP? If you are advanced enough to do it, do it. At the very simplest, you read in a tag like {foreach from=$something} and somehow translate it to <?php foreach ($something as $thing) { ?>. You check token types, etc to make sure the template tag is valid, and so on.

Which option is more scalable?

I'm working on php, mysql on a project
I'm planning to add a multilanguage option, usually I use single textfile for each php file, but I want to know if one of the followings is good or not and why.
Using one single textfile for the whole site: This would make my life peacefully because I have to make changes in one place only, but I don't know how scalable this option would be.
Using xml files for each php, is this scalable for dictionaries?
Using one single xml file, is this scalable for dictionaries?
Using a table in the db, I used this options a few times, but I read that it make the webpage slower and is not really scalable
That are my options, if any have a better one I would be greatfully, and if anyone have an advice on the pseudocode (I usually use a big array) and a replacement Welcome too :D
use gettext
wordpress is a good example if you need one
as for your question, separate language files is the only solution, letting many people work on different languages separately
I only use db when I need other people to add / modify datas in my translation.
Else I use a php file by language, defining my variables in each.

What's the most efficient way to setup a multi-lingual website

I'm developing a website that will be available in different languages. It is a LAMP (Linux, Apache, MySQL, PHP) setup, and it makes use of Smarty, mostly for the template engine.
The way we currently translate is by a self-written smarty plugin, which will recognize certain tags in the HTML files, and will find the corresponding tag in an earlier defined language file.
The HTML could look as follows:
<p>Hi, welcome to $#gamedesc;!</p>
And the language file could look like this:
gamedesc:Poing 2009$;
welcome:this is another tag$;
Which would then output
<p>Hi, welcome to Poing 2009!</p>
This system is very basic, but it is pretty hard to control, if I f.e. would like to keep track of what has been translated so far, or give certain users the rights to translate only certain tags.
I've been looking at some alternative ways to approach this, by either replacing the text-file with XML files which could store some extra meta-data, or by perhaps storing all the texts in the database, and retrieving it there.
My question is, what would be the best way to make this system both maintainable and perform well with high user-traffic? Are there perhaps any (lightweight) plugins I could take a look at?
You could give a shot at gettext. It is the way it is done in most C/C++ linux applications and it is an extension to PHP too. The idea is not very different from what you're already doing, but there are tools that ease the mantainance of translations (i.e. poedit).
For user rights to translations, gettext won't be of much help, I think you'll need to do it on your own or look at some frameworks if they have smarter solutions.
Maybe taking a look to gettext lib could help you get some hints http://php.net/manual/en/book.gettext.php hope it helps!
You will need to have a table in your database that you can use to store strings of text, each with an composite ID. the composite ID will be made up of language ID and text node ID.
You will need to give the user a chance to select a preferred language. You should make sure that you either have a default "this has not been translated" for every language you use, or a default language that your entire site can be vied in.
For every bit of text with in your web site, rather then store the text with in the page, you just assign it an ID.
When serving the page, look up the text node ID and preferred language ID and load that string of text, or the string for the default.
in our project, http://pkp.sfu.ca/ojs, we use XML files to store translation key-value pairs. Browse our code: http://github.com/pkp/pkp-lib/blob/master/classes/i18n/PKPLocale.inc.php
We use that class to read the XML files for each locale and in our code we use Locale::translate('locale.key.name');. Similar to gettext, but using an XML file for easier updating.
Looking around at web stuff today I came across this website: http://translateth.is/
It looks simple to use... copy paste in some javascript.

Efficiency of using a function to output html tags in php

Trying to come up with a basic way to display code in a way that would be nicely maintainable, I thought of doing something like this:
echo htmlfunction('a',array('href'=>'http://google.com'),'google');
to generate:
google
this would use as a global scale function to output all html tags. that way, if I ever wanted to change the way my html is displayed, I could easily do it with one tweak.
does using this kind of outputting mean a grave loss of agility in performance?
thanks.
No, but you would be reinventing the wheel and in a wrong way.
Instead of writing echo title("bar"); to echo <title>bar</title>, use a templating engine to output your dynamic data inside a static HTML template, that looks like <title>$title</title> where your code has $template->assign('title','bar');.
That way you will be keeping markup as markup and code as code and in separate files, which is a worthy goal in at least the maintainability and flexibility departments.
Look, for example, at Smarty
I would avoid writing functions like that in most cases. Notice how it takes more code to write than you actually have output. That's also additional processing the server is going to need to do each and every time. It probably won't be a huge performance problem at first, but if used excessively, it could be bad.
If you want to abstract presentation from logic, might I recommend a template engine like Smarty
No, it would not cause a grave loss of agility -- it would likely be hardly noticeable. Many PHP content management systems (such as Drupal and Joomla) do the same sort of thing for all their links.

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