Antlr parser integration in Symfony2 - php

As part of a professional project, I have need of a small parser for interpreting boolean-type inputs. I was able to use Antlr to create a working parser, and I was wondering if anybody here had experience and/or tips on integrating this parser, with the required Antlr libraries, into my Symfony2 application.
I have a class defining individual conditions (such as "attribute is greater than argument"), and I needed a way to combine these different conditions to create filters on the data within my application. The best way I found was to create another "container" class, referencing these conditions and having the information needed to combine them to produce the filter I need (basically a combination of DQL conditions). My problem stems from the client's request of being able to save and modify these filters, meaning I needed a simple way to keep them in database and recreate the whole filter.
Having these condition objects, I chose to use a Domain-Specific Language that I can use to save queries in the container (I dislike directly saving queries since they're difficult to modify afterwards IMO). I can save my filters in the container class in the form "((NOT condition1 AND condition2) OR (condition1 AND NOT condition2)) AND NOT condition3 OR condition4.
I have generated the associated parser, but now I need to integrate it in my Symfony project, meaning I need to integrate the Antlr library as well, and I don't really know how to proceed. I was thinking I could attempt to format the Antlr library as a Symfony Bundle, but I'm wondering what other ways there could be, and the comparative difficulties.
Does anybody have alternative approaches, as well as associated pros and cons?

Related

Template engine for single PHP page with structured content?

I'm planning to build a single PHP web page that will contain lots of structured data in nested divs, spans, bootstrap elements etc., like:
Hardware
Notebooks
HP
Apple
Dell
Tablets
Apple
Samsung
Software
Operating Systems
Windows 10
...
The list ist really long with far more than 100 elements. The elements will change from time to time, but the structure will be the same for all elements and sub-elements.
Now, I wonder if plain HTML+CSS is the best way to code this page. As the structure of the elements is always the same, so it would probably be a good idea to use templates. However, I'm not sure if I really should set up a database and some kind of PHP framework like Slim or Laravel/Lumen in order to generate the code. After all, it's just a single page without and routing, forms, login etc. So this might be too much.
Perhaps, a templating engine like Plates could be the answer? But where should I store the data?
What would be your choice for such a use case? Single page with lots of structured data?
Any help is greatly appreciated!
Based on your subject line, I want to clarify something and then suggest a solution.
PHP Components & Composer
State of the art PHP development utilizes Composer to orchestrate component libraries. This could be in the form of a full stack framework or in the form of just a few specific component libraries that solve the problems you have.
Datastores
Your sample shows data with simple hierarchy. Certainly for ease of maintenance a datastore of some type would be helpful. A relational database or a document database will do the job. If that is what you want I'm going to suggest you use a specific ORM or at least a portion of it, and that ORM is Doctrine.
Why Doctrine? Because it supports a number of the most popular open source RDBMS, and it also allows you to use it's DBAL layer without the full ORM, if you just want to implement a few simple queries. With that said, if you have the option of using MongoDB, MongoDB collections support hierarchies very well. A great feature of Doctrine2 is that it has support for MongoDB, which differentiates it from most other PHP ORM's.
The only real reason to go to all this trouble is that you also intend to create an administration tool that will let you maintain your hierarchical data. If you don't, you could just as easily have a script that you include that has the data in PHP array form.
Templating
For templating, my suggestion is that you use Twig. As part of the Symfony components, Twig is both self contained and part of the Symfony full stack framework. It's robust and well designed, and has numerous features (although to be fair, Laravel's Blade has similar features in most cases) and includes support for ESI which could be a great feature for a relatively static page like the one you describe.
Templating in twig, vs writing PHP code to do the same, lets you focus on your markup and avoid introducing a lot of PHP code that will turn your view code into spaghetti.
Components
The important thing is that you can simply use the few components you need to support your application, and you certainly don't need either Laravel or Symfony. Since Symfony began its life as components (and was the foundation for the Laravel project in fact) I'd push you towards the Symfony components, although at the end of the day, you could also utilize parts of Laravel (Blade, Eloquent) in the same way that I'm advocating you use portions of Symfony. Symfony simply is the community and stack I prefer, and has a longer history of being used on a component basis in other projects.
Try out the new minimal Symfony4
Last but not least, the newest version of Symfony (Symfony 4) is really worth looking at for a number of reasons. It essentially is now a micro framework, that comes with the bare minimum of components. They advertise it as 70% smaller than v3.
What differentiates this release is the innovation of Symfony flex with recipes and Composer integration. It is now built to automate a lot of the things that you might otherwise have had to figure out on your own for putting these components together into an application.
Take a look at it and see if it might help you get your application built with minimal components and minimal time spent having to learn how to make things work together.
In summary, I'd suggest you consider:
Symfony Components (You might want a few more depending on your
final solution).
Doctrine2
Twig
Symfony4

Ajax loading for complex projects

My problem is actually not the ajax loading itself, more the capability to load it without javascript. I mean, I cope easily when I code my whole project just based on ajax-availability OR just without the use of ajax.
//EDIT: Although Arend already had a more or less valid answer, at the same time 'there is no direct answer to this question'. However, I'd like to see some other approaches of developers for scenarios like mine though! Even just a few links can help!
Basically I just get frustrated, coding everything twice on the same page to make sure that both users without and with Javascript enabled have the same experience. It's annoying and I was always wondering how others solve this problem.
When I update for example two divs with dependency on the same variables, it gets messy. Here's an example:
non-js-version
require 'classobject.class.php';
$another_var = 'something';
$class = new classobject($_POST['variable']); // just an example to show that this is dynamic - I'm aware of injection!
$function = $class->returnsth(); // returns 1
if(isset($_POST)) {
echo '<div id="one">Module 1 says:'; $require 'module_one.php'; echo '</div>';
echo '<br /><br />';
echo '<div id="two">Module 2 says:'; $require 'module_two.php'; echo '</div>';
}
Now in module_two.php and module_two.php I have code that executes differently depending on the return variable of $function.
Like:
if($function >= 1 && another_var != 'something') {
// do stuff
}
else {
// do other stuff
}
Now as this works easily with a reload, when I want to load the two modules on keyUp/enter/submit or whatever, I have basically a few problems:
I have to send the $_POST variables manually to the modules to use them
I have to re-execute the class & it's methods and make a link (require_once) to them in each of the module-files.
As $another_var is not existent in the modules, I'd have to send this variable to each modules, too (with post for example) and then before it can be used, I'd have to 'change' it like $another_var = $_POST['another_var'];
I find this mildly annoying and I wonder how you guys do that. I hope my way of coding is not too silly, but I can't think of another way. It's probably hard to relate to my very basic example, but to bring a whole project with the code would be too much. To sum it up, I'm looking for a better way to code and clean this mess up - there must be a way! I thought about sessions, but for compatability I don't want to rely on them either (if someone doesn't allow cookies).
In case you can't relate to what I'm trying to accomplish with that way of having my code assembled, I'll explain a scenario I'm facing quite a lot (not important if you already understand my misery):
Basically I have my index.php page where everything gets executed, with the html body and css styling and so on. This page expects some variables, that get set from the page that requires the index (like $another_var in my example).
Now other variables can get set too (from a form for example). Depending on that different classes and methods load new variables (arrays) that get used in while-loops in my modules to echo everything out.
Hope that's not too abstract. Think of a booking system where some variables are set from the page you are coming from (the event you want to book) and then a few more things get set by the user (a timespan, some preferences,...). In the end it's supposed to show results from the database all the way to the end-result - you can say the user narrows the results from step to step.
There is no direct answer to your question, but there is some food for thought.
Seperation of concerns
You can think about if you can perhaps seperate your buisness logic and layout logic. Often the use of a template engine can help greatly with that. I've had positive experiences with for example Twig or Smarty (was some time ago, not sure how they measure up right now). It requires you to write your code in a (less linear) way, but more logical.
A typical example of an OOP like seperation of concerns might be something like this:
$this->setParam('Myparam','myvalue');
if ($this->isAjax())
{
$this->setTemplate('ajax.php');
$this->setLayout(false);
} else {
$this->setTemplate('normal.php');
$this->setLayout('Mylayout');
}
return $this->render();
It is an imaginative situation, which can be found in many MVC like applications and frameworks. The main idea is that you should have the possibility to seperate your layout from your data. I would suggest looking at some of the modern frameworks for inspiration (like symfony, codeigniter, zend framework).
Glossary / Often applied concepts in a decoupled PHP application
Here is a quick list of concepts that can be used.
Example mvc in php: http://www.phpro.org/tutorials/Model-View-Controller-MVC.html
Note: I don't really like the implementation. I much more prefer the existing frameworks. I do like the explanation in total of this tutorial. E.g. for me this link is for learning, not for implementing.
Silex
For a simple decoupled php micro-framework I would really recommend silex, by the makes of symfony2. It's easy to implement, and to learn, but contains mainy of the concepts described here; and uses all the php 5.3+ goodies such as namespacing and closures.
see: http://silex.sensiolabs.org/
Frontcontroller Pattern
Only have one, and one only point of entry for your code. I usually only have one, and one only point in your application. Usually a frontcontroller 'dispatches' the request to the rest of the application
http://en.wikipedia.org/wiki/Front_Controller_pattern
Routing
A routing system is often used in combination with the frontcontroller pattern. It basically describes which URL is connected to which module / controller. This allows you to change the way people access your app without changing the urls.
See: https://stackoverflow.com/questions/115629/simplest-php-routing-framework
Controller
A controller is the place where buisness logic is applied. Getting the data from the database, checking privileges, setting the template, setting the layout, etc. (although this is also moved outside the controller if it becomes too big of a seperate concern).
Model
The model basically is the layer in which use manage your database. This can be a simple class where you move all your mysql_* functions, or it can be a full-featured ORM. The main philosphy is that all the logic related to fetching and placing information in the database is seperated.
One step up: ORM
An often used method in applications are Object Relational Models, these 'map' SQL records to PHP objects. Doctrine and Propel are two of these well worked out libraries. I heavily rely on these systems in my development. In this sense, the doctrine or propel part will represent the model layer.
Doctrine: http://www.doctrine-project.org/
Propel: http://www.propelorm.org/
Other ORMS: Good PHP ORM Library?
PHP ORMs: Doctrine vs. Propel
View:
The view usually consists of a templating engine. Some use plain PHP as a template, others, such as symfony create a seperate scope in which variables are placed. There are many discussions and opinions about what is best, one is right here on stackoverflow:
Why should I use templating system in PHP?
PHP vs template engine
Ones I like:
- Twig: http://twig.sensiolabs.org/
- sfTemplate: http://components.symfony-project.org/templating/
- Smarty: http://components.symfony-project.org/templating/
Decoupling mechanisms:
Event based systems
Using events in your can help to seperate the code. For example if you want to send an email after a record has been saved, events are a good solution to do that; in general the model should not have to know about email. Thus events are a way to connect them: you can let your -email-send-class listen to certain records in order for them to send the right email. (Perhaps you'd rather want your e-mails send from your controller, this is probably a matter of taste).
Dependency injection
When using OOP code in PHP many relied on having singleton classes running around (configuration, etc). From an OOP point of view, this can be considered bad, because it's hard to test it, and it's not considered very elegant to have dependencies running around like that. Dependency Injection is a pattern that came form Java and is now used in the newer frameworks to get around this. It might be a bit difficult to wrap your head around, but you will see it coming back in several new frameworks.
Dependency injection in php: Dependency Injection in PHP 5.3
Frameworks:
A lot of these methods are difficult, or a lot of work to implement yourself. Many will reside to a framework for this. You may or may not need a framework. You may, or may not want to you a framework, it's your choice. But it's still useful to learn how the frameworks do it, and not try to reinvent the wheel yourself.
The no-framework php frameworks: https://stackoverflow.com/questions/694929/whats-your-no-framework-php-framework
Good habits: https://stackoverflow.com/questions/694246/how-is-php-done-the-right-way
Frameworks worth looking at (imho): CodeIgniter, Kahona, CakePHP, Symfony (1.4/2.0), Silex, Zend Franework, Yii. There are many many more, each with their dedicated fans and haters.
I wrote something like this with PHP. I already had abstracted the rendering of every page such that I define a $content variable and then require('layout.php'). The $content variable is just a big HTML string.
I wrote a PHP function to determine if request was AJAX or not.
The non-AJAX responses render the layout with $content in the middle, b/t header and footer layout content.
AJAX requests basically get this: json_encode(Array("content"=>$content)). And I use jQuery to get the HTML out of the JSON response and modify the DOM. Using json_encode() will handle escaping the string for javascript.
In the end, I effectively have AJAXified every page w/o over-engineering a complex solution.
Any browser that supports AJAX can also open a link in a new tab/window to simulate the non-AJAX request. (Or bookmark/share a link, too.)

CakePHP for big projects

We are evaluating some PHP Frameworks for a productive website. CakePHP looks pretty interesting but we have no clue if it fits our needs.
Basically when you check the documentation and the tutorials for CakePHP it looks really promising. Nevertheless there were always some things that bugged me with frameworks so far, maybe someone who already used CakePHP in a productive project could answer this questions for me?
Writing/Reading data for single records looks pretty neat in CakePHP. What happens if you want to read data from multiple tables with complex conditions, group by, where clauses? How does CakePHP handle it?
Scaffolding looks pretty nice for basic administration interfaces. How easy is it to customize this stuff. Let's say I have a foreign key on one of my tables. When I create a scaffolding page, does CakePHP automatically create a dropdown list for me with all the possible items? What if I want to filter the possible items? Let's say I want to combine two fields into one field in the view part, but when I edit it, I should be able to edit both of those fields individually. Does this work?
Do you think you were faster in development with CakePHP than with let's say plain PHP?
I've used CakePHP, Zend Framework and I've also written applications "from the ground up" with nothing more than homegrown classes and such. To that I'd like to mention that I use CakePHP regularly so, take that as you will.
(Writing/reading data, complex conditions) You can certainly do everything you mentioned. Others are correct in that it attempts to abstract away SQL operations for you. I've yet to have a query that I couldn't translate into Cake's "parlance"; complex geospatial queries, joins, etc.
(Scaffolding, complex conditions) The scaffolding is really only meant to serve as a "jump start" of sorts to help make sure your model associations and such are setup correctly and should not be used as a permanent solution. To that end, yes it will do a fairly good job at introspecting your relationships and providing relevant markup.
(Faster development) Of course. There is a large community with a vast number of plugins or examples out there to help get you started. Regardless of what you pick, choosing a framework will almost certainly make you "faster" if only for handling the minutiae that comes with setting up an application.
It really depends on your definition of "large". Are you referring to big datasets? A very complex domain model? Or just lots and lots of different controllers/actions?
Writing/Reading data.
Anything you can do with plain SQL you can do in CakePHP. It may not always be very nice to do, but at it's worst it's no worse than straight SQL.
But you really shouldn't be thinking about queries. You should be thinking about your domain model. CakePHP implements the active record pattern. It works very well if your domain model maps nicely to an active record pattern. But if it does not, then I would not recommend CakePHP. If your domain model doesn't map to Active Record then you will spend a lot of time fighting the Cake way of doing things. And that's no fun. You would be much better off with a framework that implements a Data Mapper pattern (e.g. Zend).
Scaffolding
Scaffolding is temporary. It does handle foreign keys (if you define them in the model as well as in the database) but that's it. You can't modify the scaffolding. But, you can bake them!
When you bake a controller or view then you're basically writing the scaffold to a file as a jump-off point for your own implementation. After baking, you can do anything that you want. The downside of baking is that it doesn't update anymore when the models or database changes. So, if you bake a controller and views and you add fields to your model, then you need to add those fields manually to your controller and view code.
speed of development
In my case, I'm a lot faster developing a website in CakePHP then in plain code. But only if Active Record suits the application! See my first point. Even then, Cake is probably still faster, but I would be faster still with a better suiting framework.
Some other thoughts
large datasets
If you have very large datasets and big query results then Cake can be a problem. A find() operation wants to return an associative array, so all the rows are read, parsed and converted to arrays. If your result set is too large you will run out of memory. CakePHP does not implement ResultSet objects like many other Active Record implementations and that is a definite downside. You end up manually paging through your own data with subqueries. Yuck. Wich brings me to my next point:
arrays
Learn to love them because CakePHP does. Everything is an array and often they are large, complex and deep. It gets really annoying after a while. You can't add functions to arrays so your code is more messy than if CakePHP would have used nested object instances. The functions you can add to those objects can help keep your code clean.
oddities and inconsistencies
CakePHP has some real nasty stinkers hidden deep within. If Active Record suits your application then you will probably never run into them, but if you try to mold CakePHP into something more complex, then you will have to fight these. Some examples:
HABTM through a custom model uses the definition from the other side of the relationship that you're working on.
Some really odd places where your before/after triggers aren't called (e.g. not from an updateAll)
odd Model->field() behavior. It always queries from the database. So, be careful about updating model data without immediately saving it to the database. Some CakePHP functions fetch data from Model->$_data and some use Model->field(). The result may be entirely different resulting in some very hard to track down bugs.
In short
I would highly recommend CakePHP even for "large" sites, as long as your domain model fits nicely on top of Active Record. If not, pick a different framework.
Since you are asking for opinions, then I have to say that I advise AGAINST CakePHP.
My biggest gripe with it, is that it's still using PHP4 (written in and code generated). So, why go backwards? It is compatible for PHP5, but the framework itself revolves around PHP4.
I would recommend taking a look at Symfony or Zend. Symfony being the best if you want more structure in place - it forces you to adhere to the MVC structure that it has established.
The alternative is Zend, but it's more of a 'do-it-yourself' framework, or rather more of a set of libraries. You need to put it all together yourself, and it doesn't have any strict structure like Symfony.
There are obviously other frameworks, but I recommend the fore-said. Another one that you may want to look at is Codeigniter.
CakePHP tries to abstract away the database, so you write very little SQL (however, you write a lot of SQL snippets).
The basic process is to define your models, then define the relationship between models (hasOne, belongsTo, hasMany, hasAndBelongsToMany). You can put any conditions or default ordering on these associations you like. Then, whenever you fetch a row from the database, any associated rows are automatically fetched with it. It's very easy and powerful.
Everything comes with a bunch of configuration options, giving further flexibility. For example, when fetching data there is a recursion option which takes an integer. This value is how many associations deep Cake should fetch data. So if you wanted to fetch a user with all their associated data, and all the joined data to THAT, it's trivial.
Pretty much anything can be overridden on defined on the fly, and you can always fall back to writing your own SQL, so there's nothing Cake prevents you from doing...
I've not found much use for scaffolding. The answer to your question is yes, it'll auto populate joined dropdowns, etc. But I've never used it as a basis to build an interface. I tend to use a database tool to populate data early on rather than scaffolding.
I've built and also maintain several web-apps on CakePHP, and it is without question faster than 'rolling your own'. But I think that's true of any decent framework!
Unfortunately one of the weaker points is the documentation. Often you need to Google for answers as the official documentation is a bit hit-and-miss at times.
Just go with Yii framework, it's the best in this category.
(Note: This is a subjective question. You are asking for opinions. So I hope you don't mind if I give mine.)
(Edit: Ops. I mixed Cake with CI)
I used Code Igniter a while back. It did everything it should and was fairly easy to understand. However, for big projects, it lacked features. Many CI proponents say that this is it's strength as it keeps it fast and can make little RAM. This is true.
However, after developing one application with it, I found myself looking elsewhere so I would not have to write code that must have been written before. I looked at CakePHP and found it too restrictive and automagical. In particular, I needed some kind of ACL functionality. This lead me to Zend Framework. I learned that it is loosely coupled. I can include only the files I need. I can also make use of Zend_Application for large projects. It's object oriented design is a must when developing and maintaining large projects.
Yes, CI and CakePHP helped me to develop faster than with plain PHP. However, there are much more powerful frameworks. I hear and see good things about Symphony. There are quite a few more. I'm sure others will point them out.

How to Stop Wasting Time in PHP

As a programmer, I love developing algorithms. I love to take a problem and work out a clean, efficient, readable, elegant solution. I seem to find, however, that the majority of my time is spent validating and cleaning form data, and passing it along to prepare various SQL statements. Perhaps this is "just the way it is" but I suspect I may be doing it wrong.
What do you do to avoid the deathtrap of endlessly validating input and building database interactions? Do you use a third-party library? Write your own library? Or is that simply the way it is?
Most people abstract out a lot of the form validation and database transactions using some kind of framework. One example is the Zend framework Forms. I've seen people write their own libraries to add similar functionality.
For example, I've written my own simple library for smaller clients as well (just making each form element it's own class with a Basic "element" base class), a set of validation classes, and a Form class to wrap the elements. The form class calls the validate methods for each element and turns their data into an array that can be fed to a database class.
Your best bet is to figure out the needs for the websites and forms you are building. (Complex forms may be too difficult to abstract out). But simple forms could have their coding process stream lined without much difficulty.
If you're not using a framework (or can't), then you should definitely check out the php Filter methods: http://php.net/manual/en/book.filter.php
They're built in as of PHP 5.2
I've yet to see a good DB extraction outside of a framework, but the PDO abstraction layer is a good start ( http://php.net/manual/en/book.pdo.php )
P.S. I use Drupal too, when I can. The webform module in particular makes all this ridiculously easy.
I use Drupal for that, but you may prefer using some framework.

Is there any php framework which exactly reflect the msaccess

I am fond of dbstructure definition of msaccess which lets defining at once and creating the data entry forms, datatables and reports at once easily.
I have been searching for some framework which would generate the data entry forms, data tables and reports easily. I guess the only thing I need to define is complete datatable structure.
Is there any like that or better one than that?
EDIT:
well i am afraid that PHP frameworks have been limited to programmers only. I would like to extend it with some automated functions like autoform in msaccess which would generate data entry form, auto report for data listing. So that my development time would be again some less. I found doctrine nearly matching my specification but not sure as i haven't fully explored doctrine
Cake offers both "hard" (bake) and "soft" scaffolding, which should be very close to what you want. It's still only meant as a quick proof-of-concept tool and to get you up and running faster so you can concentrate on programming the business logic. It's not meant as a hands-off solution nor to be used in production.
What you seem to be looking for is a database frontend like phpMyAdmin or SQL Buddy, not a PHP framework.
Symfony provides an admin generator that builds all the forms on the fly and it will also update itself when you change your db schema. It is based on doctrine which you say you looked at so that would make things a bit easier for you.

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