Symfony (I)：添加一个Webpage（Action，Template，Helper）

AddingaPage
Insymfony,thelogicbehindpagesisstoredintheaction,andthepresentationisintemplates.

AddinganAction

The"Hello,world!"pagewillbeaccessiblethrougha

myAction

action.Tocreateit,justaddan

executeMyAction

methodtothe

mymoduleActions

class,asshowninListing4-2.

Listing4-2-AddinganActionIsLikeAddinganExecuteMethodtotheActionClass

<?php

classmymoduleActionsextendssfActions

{

publicfunctionexecuteMyAction()

{

$today=getdate();

$this->hour=$today['hours'];

}

}

Thenameoftheactionmethodisalways

execute``Xxx``()

,wherethesecondpartofthenameistheactionnamewiththefirstlettercapitalized.

Now,ifyourequestthefollowingURL:

http://localhost/myapp_dev.php/mymodule/myAction

symfonywillcomplainthatthe

myActionSuccess.php

templateismissing.That'snormal;insymfony,apageisalwaysmadeofanactionandatemplate.

AddingaTemplate

Theactionexpectsatemplatetorenderitself.Atemplateisafilelocatedinthe

templates/

directoryofamodule,namedbytheactionandtheactiontermination.Thedefaultactionterminationisa"success,"sothetemplatefiletobecreatedforthe

myAction

actionistobecalled

myActionSuccess.php

.

Listing4-5-TheAlternativePHPSyntax,GoodforTemplates

<p>Hello,world!</p>

<?phpif($test):?>

<p><?phpechotime();?></p>

<?phpendif;?>

Listing4-4-TheUsualPHPSyntax,GoodforActions,ButBadforTemplates(不推荐)

<p>Hello,world!</p>

<?php

if($test)

{

echo"<p>".time()."</p>";

}

?>

IfyouneedtoexecutesomePHPcodeinthetemplate,youshouldavoidusingtheusualPHPsyntax,asshowninListing4-4.Instead,Listing4-5.

GatheringInformationfromtheUserwithForms

AhelperisaPHPfunctiondefinedbysymfonythatismeanttobeusedwithintemplates.ItoutputssomeHTMLcodeandisfastertousethanwritingtheactualHTMLcodebyyourself.Usingsymfonyhelpers,youcanhavethesameresultasinListing4-8withthecodeshowninListing4-9.

Listing4-9-ItIsFasterandEasiertoUseHelpersThantoUseHTMLTags

<p>Hello,world!</p>

<?phpif($hour>=18):?>

<p>OrshouldIsaygoodevening?It'salready<?phpecho$hour?>.</p>

<?phpendif;?>

<?phpechoform_tag('mymodule/anotherAction')?>

<?phpecholabel_for('name','Whatisyourname?')?>

<?phpechoinput_tag('name')?>

<?phpechosubmit_tag('Ok')?>

</form>

If,intheexampleinListing4-9,youthinkthehelperversionisnotreallyfastertowritethantheHTMLone,considerthisone:

<?php

>$card_list=array(

>'VISA'=>'Visa',

>'MAST'=>'MasterCard',

>'AMEX'=>'AmericanExpress',

>'DISC'=>'Discover');

>echoselect_tag('cc_type',options_for_select($card_list,'AMEX'));

>?>

ThisoutputsthefollowingHTML:

<selectname="cc_type"id="cc_type">

<optionvalue="VISA">Visa</option>

<optionvalue="MAST">MasterCard</option>

<optionvalue="AMEX"selected="selected">AmericanExpress</option>

<optionvalue="DISC">Discover</option>

</select>

Youshouldalwaysusethe

link_to()

helpertocreatehyperlinkstoyourapplication'sactions.

<?phpecholink_to('Ineversaymyname','mymodule/anotherAction?name=anonymous')?>

MostHelpersAcceptanOptionArgument

//Optionargumentasanassociativearray

<?phpecholink_to('Ineversaymyname','mymodule/anotherAction?name=anonymous',

array(

'class'=>'special_link',

'confirm'=>'Areyousure?',

'absolute'=>true

))?>

//Optionargumentasastring

<?phpecholink_to('Ineversaymyname','mymodule/anotherAction?name=anonymous',

'class=special_linkconfirm=Areyousure?absolute=true')?>

//Bothcallsoutputthesame

=><aclass="special_link"onclick="returnconfirm('Areyousure?');"

href="http://localhost/myapp_dev.php/mymodule/anotherAction/name/anonymous">

Ineversaymyname</a>

GettingInformationfromtheRequest

Whethertheusersendsinformationviaaform(usuallyinaPOSTrequest)orviatheURL(GETrequest),youcanretrievetherelateddatafromtheactionwiththe

getRequestParameter()

methodofthe

sfActions

object.Listing4-13showshow,in

anotherAction

,youretrievethevalueofthe

name

parameter.

Listing4-13-GettingDatafromtheRequestParameterintheAction

<?php

classmymoduleActionsextendssfActions

{

...

publicfunctionexecuteAnotherAction()

{

$this->name=$this->getRequestParameter('name');

}

}

Listing4-14showshowthe

anotherActionSuccess.php

templatewouldretrievethesame

name

parameter.

Listing4-14-GettingDatafromtheRequestParameterDirectlyintheTemplate

<p>Hello,<?phpecho$sf_params->get('name')?>!</p>

Note:TheusualPHPvariables(the

$_POST

,

$_GET

,or

$_REQUEST

)won'tworkanymore