Yet another blog about PHP, HTML and CSS

Configuring Nette in Neon

Petr 'PePa' Pavel — Mon, 18 Feb 2013 10:31:00 +0000

I bet you didn’t know it but Nette’s internal behaviour can be configured quite extensively in config.neon. Default form error messages, switching on/off debugger panels, changing mailer to use SMTP instead of mail() and so on. All of this can be set up in PHP but keeping configuration out of your code helps making it easier to read. Do have a look, it has a great potential. As usually, the documentation is pretty bare and it’s up to us to discover the whole truth. This post contains some additional information that I scavenged in forums or discovered myself.

Assign user a session namespace (session is the default storage):

services:
nette.userStorage:
setup:
– setNamespace("myName")

Install custom macros using a factory:

factories:
nette.latte:
class: NLatteFilter
setup:
– CustomMacros::install(::$service->getCompiler())

Use your own database debugger panel:

services:
nette.database.defaultConnectionPanel: NotORM_DatabasePanel

Switch mailer to SMTP/localhost in order to catch all e-mails with MailSnag:

development < common:
nette:
mailer:
smtp: true
host: localhost

Post a comment if you know more goodies.

You thought using Skype was secure?

Petr 'PePa' Pavel — Mon, 13 Aug 2012 11:25:00 +0000

Many of us send sensitive information over Skype chat in order to prevent a third party from reading it. Think login credentials for example. What you may not know is that Skype is set by default to store chat history on your hard disk. Nothing wrong with it if it weren’t in plain text!

All right, it’s not exactly plain text, it’s SQLite but that’s no obstacle for a tech savvy person. Even keyboard shy people can download a plug-in for their favourite file manager (plugins here: FAR Manager / Total Commander). But even without a SQLite browser, you can see bits and pieces of your messages. Just open the file with any text editor. Don’t take my word for it, have a look yourself (path is for Windows 7):

C:\Users\\AppData\Roaming\Skype\\main.db

If using SQLite browser, look for table Messages. You’ll find all your private messages that you’ve sent or received in the past on this computer. All it takes for someone to see them is to sit at your keyboard when it’s not locked. Or send a virus. Also, realize that the recipient of your messages has his or her copy as well.

Now that I have your attention, here comes even worse news. You can’t simply purge your history. Don’t let yourself be fooled by that sweet looking button in your Skype settings. It just doesn’t work properly. I assume it’s because the records are only marked as deleted, not physically removed from the file.

You have to physically remove the file (wiping it, if you’re extra concerned) which unfortunately also removes all of your cached profile information. You will loose groups assignment, real names of people who haven’t logged in recently, your picture profile… Don’t ask me why when this information is also stored on the server. It just happened to me. Good luck with convincing your friends or company partners to do this in order to purge your messages.

I continue to send sensitive information over Skype, I just don’t store it in the history now. Luckily, I don’t need to worry about Skype company monitoring the traffic because I’m not an interesting target. But that’s a different story ;-)

Dynamic snippets for repeated forms

Petr 'PePa' Pavel — Wed, 11 Apr 2012 19:17:58 +0000

At the time of this writing, Nette lacks a good support for dynamic snippets. You can define them wrapped in a static snippet but you can’t invalidate them individually (unless they each belong to a different control, I think). You can only invalidate the static parent snippet which means you receive all its dynamic children snippets in the payload.

If you defined only a few snippets with small amount of data in each then no big deal. If however, you have a pageful of forms, each form containing a snippet that you want updated upon the parent form submission then you have to resort to tricks. For instance, you don’t want a message “Saved” displayed in each row/form in a product administration table.

I’m going to assume that you know how to submit forms via AJAX. Your application is already working with AJAX and the only missing piece is the dynamic snippets invalidation.

The trick that I ended up using is kind of mirroring the built-in functionality. I keep track of invalidated dynamic snippets and skipping definitions of those that haven’t changed. Sounds more difficult than it is, actually.

Notice that I define invalidSnippets in startup().

class Admin_ProductPresenter extends NPresenter {
protected function startup() {
parent::startup();
// this is better placed into BasePresenter
$this->template->isAjax = $this->isAjax();
$this->template->invalidSnippets = array();
}
public function renderDefault() {
// load products from db
// and set defaults with $this["productForm-$productId"]->setDefaults($data);
}
public function createComponentProductForm() {
// create your repeated forms
return new NMultiplier(function() {
return new ProductForm();
});
}
}

When processing form submission in ProductForm::process(), I take the form’s unique identificator and use it to mark all its snippets as invalidated.

class ProductForm extends NAppForm {
public function __construct($parent = null, $name = null) {
// form elements are added here
$this->onSuccess[] = callback($this, ‘process’);
}
public function process(NAppForm $form) {
$values = $form->getValues();
// update the product in db
if ($this->presenter->isAjax()) {
$this->presenter->invalidateControl("products");
// invalidate the wrapping static snippet
// $this->presenter->invalidateControl("message-".$productId);
// it makes no sense to invalidate the dynamic snippet – it doesn’t do anything
$productId = $values[‘productId’];
$this->presenter->template->invalidSnippets[$productId] = true;
$this->presenter->template->message = ‘Saved.’;
} else {
$this->presenter->flashMessage("Saved.");
$this->presenter->redirect(‘this’);
}
}
}

Reaching from ProductForm over to the parent presenter’s template is smelly but let’s keep it short here. You can attach another method to onSuccess[] and do the presenter related stuff in your presenter’s method.

And here’s the template. Notice that I define the snippets themselves only if they are needed. That is during the initial non-AJAX rendering or if they have been invalidated.

{snippet products}
{* this is the static wrapper that Nette needs to allow dynamic snippets *}
{foreach $products as $product}
{var $productId = $product['id']}
{form productForm-$productId}
{input name} {* your form elements *}
{input save} {* something to submit the form with *}
{* wrapper: only define if invalidated or during the initial rendering *}
{if isset($invalidSnippets[$productId]) || !$isAjax}
{snippet message-$productId span}
{isset($message) ? $message}
{/snippet}
{/if}
{/form}
{/foreach}
{/snippet}

You can define as many dynamic snippets as you want just make sure their name is unique (e.g. “something-$productId”) and you wrapped them with the if statement.

There’s also an alternative way, a completely different approach which ignores all the above. And that’s to detect a submitted form in the presenter and only work with its product further on. The added benefit is reduced server load – you don’t process information for other products only to throw it away at the end. The same for the template – define only this particular product’s form.

Converting hexadecimal RGB code to decimal with a bookmarklet

Petr 'PePa' Pavel — Thu, 22 Mar 2012 16:23:08 +0000

Many applications use the default Windows colour picker which unfortunately, doesn’t support hexa codes. Use this bookmarklet to convert and copy the decimal values from your browser to the picker. No need to bullshit around, here’s the thing :-)

Drag this onto your bookmark toolbar:
RGB hex2dec

Here’s the code for the curious souls out there. Nothing interesting. Just using built-in functionality of parseInt().

hexa = prompt(‘Enter a hexadecimal RGB code (# optional):’);
if (hexa.charAt(0) == ‘#’) {
hexa = hexa.substring(1,7);
}
var r = parseInt(hexa.substring(0,2), 16);
var g = parseInt(hexa.substring(2,4), 16);
var b = parseInt(hexa.substring(4,6), 16);
prompt(hexa, r + ‘ ‘ + g + ‘ ‘ + b);

Using NCache to store image thumbnails

Petr 'PePa' Pavel — Wed, 30 Nov 2011 09:33:19 +0000

There are many ways to handle image thumbnails. Sites with heavy traffic generate resized copies right after the original image is uploaded. Light traffic sites on the other hand, prefer to wait until the thumbnail is actually requested. Nette offers a few creative ways to handle this:

You can use .htaccess to catch requests for non-existent thumbnails and redirect them to your script.
Following the same theme, you can also use your ErrorPresenter to generate the thumbnail and override the response code (so that it’s not 404).
An unusual solution is to use a helper and generate the thumbnail when rendering your template.
Or simply use a presenter action.

In any of these cases, you need to decide where you’re going to store the thumbnail and how you’re going to delete/update it when the main image changes. This is where you can use the excellent built-in caching aparatus.

To keep the demonstration simple, I’m going to use the simplest of the pack, a presenter action. This goes into your BasePresenter.

public function sendResampled($model, $id, $attribute, $width, $height) {
$entity = $model->getById($id);
// a simple database query that returns a single row with the given id
if (!$entity[‘id’]) {
throw new NBadRequestException("Entity no longer exists.", 404);
// the whole database record is gone
}
$fullFilePath = $model->getUploadedFile($id, $attribute, $entity[$attribute]);
// a custom model method that returns full path to the main image file
if ($fullFilePath === false) {
throw new NBadRequestException("This entity has no image.", 404);
}
/*
* Now the interesting part: storing a thumbnail in NCache
*/
$configurator = NEnvironment::getConfigurator();
$cache = new NCache($configurator->container->cacheStorage, ‘ResizedImages’);
// ResizedImages is my own identificator – change to whatever you please
$cache->clean();
// deletes all timed-out/orphaned thumbnails; this call can go into cron instead
$key = get_class($model)."|$id|$attribute|${width}x${height}";
$cachedImage = $cache->load($key);
if ($cachedImage !== NULL) {
$image = NImage::fromString($cachedImage);
} else {
$wwwDir = NEnvironment::getVariable(‘wwwDir’);
$image = NImage::fromFile($wwwDir . $fullFilePath)->resize($width, $height, NImage::FILL)->crop(0, 0, $width, $height);
$cache->save($key, $image->toString(), array(
NCache::EXPIRE => ‘+ 2 months’,
NCache::SLIDING => TRUE,
NCache::FILES => $wwwDir . $fullFilePath
// if the source file changes, clear its cached thumbnail
));
}
print $image->send();
$this->terminate();
}

This is how you then call it from your regular presenter:

class GalleryPhotoPresenter extends BasePresenter {
public function renderPhoto($id, $width = null, $height = null) {
$this->sendResampled(new GalleryPhotoModel, $id, ‘image_file_name’, (isset($width) ? $width : 150), (isset($height) ? $height : 200));
}
}

n:src – the missing twin brother of n:href

Petr 'PePa' Pavel — Wed, 23 Nov 2011 08:56:39 +0000

As you have probably guessed by now, I love Nette. The more it hurts when I see the documentation lag behind the quality of the framework. Although I don’t understand why Latte built-in macros don’t include n:src when the oh-so-useful n:href is there my main concern however, is that nowhere in the documentation you’ll find detailed information on how to add it yourself. You’re condemned to endlessly search through forum again and crawl through various outdated subdomains of nette.org.

Here’s my solution to the n:src alias based on a post in the cookbook and the built-in n:href macro. You can also take a peek an another post of mine on how to tweak your forms using macros. As always, hopefully it’ll save you some time.

This goes into your BasePresenter:

public function templatePrepareFilters($template) {
$latte = new NLatteFilter;
$set = new NMacroSet($latte->parser);
$set->addMacro(‘@src’, create_function(
‘NMacroNode $node, $writer’,
‘extract(NCFix::$vars['.NCFix::uses(array('me'=>new NUIMacros($latte->parser))).'], EXTR_REFS);
return \’ ?> src="\’ . $me->macroLink($node, $writer) . \’ ?>"\’;
’));
$template->registerFilter($latte);
}

Yes, the code does has a high wtf factor. Just look at the n:href macro, this isn’t my invention :-) I still don’t think I fully understand it but it does the trick and does so reusing the built-in macro as much as possible.

Repeated forms on the same page

Petr 'PePa' Pavel — Tue, 22 Nov 2011 11:03:55 +0000

Often you want the user to have a form not just for one entity but for all of them on the same page. A form for each product in the same category, for example. I’m not talking about multiple different forms but multiple instances of the same form.

This topic has been discussed in the Nette forum so many times that it’s really a shame that it’s still missing in the documentation. Frustrated after an hour spent reading outdated forum posts, I offer here a complete solution based on one of the posts.

Form definition goes into /app/forms/ProductForm.php

class ProductForm extends NAppForm {
var $parent; // used in process()
public function __construct($parent = null, $name = null) {
parent::__construct($parent, $name);
$this->parent = $parent;
$this->addText(‘title’, ‘Heading:’);
…
$this->onSuccess[] = callback($this, ‘process’);
}
public function process($form) {
$values = $form->getValues();
…
$this->parent->flashMessage(‘Product saved.’);
$this->parent->redirect(…);
}
}

Here’s how you use it in your presenter:

class ProductPresenter extends NPresenter {
// this needs to go into action, not render
public function actionDefault() {
$products = …;
foreach ($products as $product) {
$this->_createProductForm($product);
}
$this->template->products = $products;
}
protected function _createProductForm($product) {
$form = new ProductForm($this, ‘ProductForm_’.$product[‘id’]);
$form->setDefaults($product);
}
}

And the final piece of the puzzle, your template:

New product form:
{form ProductForm}
{label title /} {input title, autofocus => TRUE}
{input save, value => ‘Create’}
{input body}
{/form}
Existing products:
{foreach $products as $product}
{var formName = ‘ProductForm_’ . $product['id']}
{form $formName}
{label title /} {input title}
{input save}
{input body}
{/form}
{/foreach}

As always, if it doesn’t work for you, check your Nette version and compare it with the tag below.

Refreshing current user’s identity

Petr 'PePa' Pavel — Wed, 09 Nov 2011 13:49:41 +0000

Nette stores current user’s identity in session. There are a few situations when you want to reload the identity or change it completely. For example, the user updates his profile and you want the change reflected in the page header. Or a super administrator is allowed to re-authenticate as a different user without having to know the other user’s password.

NUser has a convenient method called setIdentity() but unfortunately, it’s declared as private so you can’t use it. The solution is either to loop through the current identity and update its fields one by one, or do it nice and clean with a custom authenticator. Let me show you.

Here’s the looping method. It just does the job.

$values = array(‘id’ => 123, ‘name’ => ‘Joe Sixpack’, ‘role’ => ‘administrator’);
$currentIdentity = $this->parent->getUser()->getIdentity();
foreach ($values as $attribute => $value) {
$currentIdentity->$attribute = $value;
}

And here’s the custom authenticator. One for refreshing updated profile and another one for swapping identities.

class DummyAuthenticator implements IAuthenticator {
public function authenticate(array $credentials) {
list($values) = $credentials;
return new NIdentity($values[‘id’], null, $values);
}
}
// in presenter
$user = $this->getUser();
$newValues = UserModel::getById($user->getIdentity()->id);
$user->setAuthenticator(new DummyAuthenticator);
$user->login($newValues);

In this example, the authenticator actually does some job – it verifies that the current user is allowed to change his identity. It’s in fact authorization, not authentication, but that’s not the point here.

class ReAuthenticator implements IAuthenticator {
public function authenticate(array $credentials) {
list($currentIdentity, $newUserId) = $credentials;
$newUser = UserModel::getById($newUserId);
if (($currentIdentity->role == ‘administrator’) && in_array($newUser[‘role’], array(‘consultant’, ‘manager’))) {
return new NIdentity($newUser[‘id’], null, $newUser);
}
if (($currentIdentity->role == ‘consultant’) && ($newUser[‘role’] == ‘manager’)) {
return new NIdentity($newUser[‘id’], null, $newUser);
}
throw new NAuthenticationException("Insufficient permissions.", self::NOT_APPROVED);
}
}
// in presenter
try {
$user = $this->getUser();
$user->setAuthenticator(new ReAuthenticator);
$user->login($user->getIdentity(), 1234);
} catch (NAuthenticationException $e) {
…
}

Testing for unique value during form validation

Petr 'PePa' Pavel — Mon, 07 Nov 2011 19:07:52 +0000

Let’s talk about what happens when a user signs up for a new account. He fills in his nickname, e-mail address and password and clicks Register. When validating the e-mail address you need to check for at least three things:

the user provided one
the syntax is all right – the e-mail is formally valid and can in fact exist (which doesn’t mean it really exists)
the address hasn’t been used yet for some other account

So far not very difficult.

The tricky part comes when you allow the user to edit his profile. He can change any of the three values. When he submits the edit form the situation is one step more difficult than during registration. The e-mail address has in fact already been used – for the very user that is submitting the form. That is not the tricky part. The fun is how to get the user id when validating his e-mail address.

Without further ado, here’s the code:
(using NotORM initiated in BaseModel constructor)

class UserPresenter extends BasePresenter {
function createComponentAddEditForm($name) {
…
$form->addText(‘email’, ‘E-mail:’)
->setRequired(‘Please provide your e-mail address.’)
->addRule(NFORM::EMAIL, "Sorry, this doesn’t seem to be a valid e-mail address.")
->addRule(‘BaseModel::uniqueEmail’, ‘This e-mail is already registered.’);
$form->addHidden(‘id’);
…
}
}
abstract class BaseModel extends NObject {
static function uniqueEmail(NTextBase $control) {
// —————————————————————-
$email = $control->getValue();
$values = $control->getParent()->getValues();
$me = new self;
$queryBase = $me->db->users->where(‘email’, $email);
// Test for any record with given e-mail address
if (empty($values[‘id’])) {
return ($queryBase->count("*") == 0);
}
// Test for any record with given address – that isn’t this record
return ($queryBase->where(‘NOT id’, $values[‘id’])->count("*") == 0);
}

Tweaking your forms

Petr 'PePa' Pavel — Fri, 09 Sep 2011 13:55:39 +0000

Nette forms documentation lacks information about enhancing your forms while still using the default renderer. I offer here a list of solutions for the most common needs, using getControlPrototype(), getLabelPrototype(), getSeparatorPrototype() and setOption().

The code goes into your form factory method in the presenter. Using the default renderer means you can’t tweak the look in your template, you have to do it when you define the form.

Formatting

Very often it’s needed to add a css style or class to a field or its label. You can modify other elements too though. For instance, you can automatically place user’s text cursor into a particular field after the page loads.

$form->addText(‘subject’, ‘Subject:’)
->getControlPrototype()->class(‘wideField’)->autofocus(true);
$form->addTextArea(‘terms’, ‘Terms and Conditions:’)
->getLabelPrototype()->style(‘white-space: nowrap;’);

Radio buttons on a single line

Default renderer will place each radio button/label pair on a new line. What happens in terms of Nette is that it uses a line break as a separator. Here’s how to remove (or replace) the separator.

$options = array(‘one’ => "One", ‘two’ => "Two");
$form->addRadioList(‘type’, ‘Type:’, $options)
->getSeparatorPrototype()->setName(NULL);

Read-only

Make a form field (or a set of form fields) read-only – aka disabled. This field’s value will then not appear among $form->getValues().

$form[‘type’]->setDisabled(true);

Description

Piece of text or html element printed after the form field.

$form->addText(‘password’, ‘Password:’)
->setOption(‘description’, "Leave empty if you don’t want to change.");

Will be rendered as

Leave empty…

What if you want the description to start on a new line? Or be something else than a plain text?

$form->addText(‘password’, ‘Password:’)
->setOption(‘description’,
NHtml::el(‘div’)->setHtml(
NHtml::el(‘small’)->setText("Leave empty if you don’t want to change.")
)
);

Printing a description with form macros

When rendering your forms semi-manually with macros {form}, {label} and {input} you may also need to print the description. Nette doesn’t ship with any handy macro for that purpose but you can create your own. Best place would be your BasePresenter:

public function templatePrepareFilters($template) {
$latte = new NLatteFilter;
$set = new NMacroSet($latte->parser);
$set->addMacro(
‘description’,
‘$__desc = $form[%node.word]->getOption("description"); echo %escape($__desc);’
);
$template->registerFilter($latte);
}

Additional information on defining your own Latte macros. Don’t expect much though, it’s pretty brief.

Other things you can set with setOption()

(taken from API for Nette\Forms\ControlGroup)

label: String or Html object – Setting this option only makes sense for a group where it replaces a label defined previously with addGroup()
container: Html object – Again, only makes for a group. Good for wrapping it with a DIV for example.
description: String or Html object – Displayed after the form field, inside of a fieldset when talking about a group. Doesn’t work for buttons (addSubmit/addButton)
visual: Wraps a group with a fieldset when true.
embedNext: Understands the next group as a child when true, or as a sibling if false (default).

(Nette\Forms\Rendering\DefaultFormRenderer)

class: css class
id: id attribute