Tutorial de CodeIgniter

8/10/2019 Tutorial de CodeIgniter

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CodeIgniter Tutorial Learn

CodeIgniter in 40 minutes

http://www.revillweb.com/tutorials/codeigniter-tutorial-learn-

codeigniter-in-40-minutes/

* can also be renamed or relocated anywhere on your server. If

* you do, use a full server path. or more info please see the user

guide:

* http://codeigniter.com/user!guide/general/managing!apps.html

*

* "# $%&I'I"( )'&)+

*

*/

application!folder application

$system_pathand $application_folderis where codeigniter will look for the

respective folders, you need to update this file so that it is pointing to where you

moved the applicationand systemfolder. Change this file to read the

following:

/*

*---------------------------------------------------------------

* ))$12 #'31% "&21

*---------------------------------------------------------------

*

* $his variable must contain the name of your system folder.

* Include the path if the folder is not in the same directory

* as this file.*
http://www.revillweb.com/tutorials/codeigniter-tutorial-learn-codeigniter-in-40-minutes/http://www.revillweb.com/tutorials/codeigniter-tutorial-learn-codeigniter-in-40-minutes/http://www.revillweb.com/tutorials/codeigniter-tutorial-learn-codeigniter-in-40-minutes/http://www.revillweb.com/tutorials/codeigniter-tutorial-learn-codeigniter-in-40-minutes/


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*/

system!path ../codeigniter/system

/*

*---------------------------------------------------------------

* &55'I6&$I#" #'31% "&21

*---------------------------------------------------------------

*

* If you want this front controller to use a different application

* folder then the default one you can set its name here. $he folder

* can also be renamed or relocated anywhere on your server. If

* you do, use a full server path. or more info please see the user

guide:

* http://codeigniter.com/user!guide/general/managing!apps.html

*

* "# $%&I'I"( )'&)+

*

*/

application!folder ../codeigniter/application

To remove index.phpfrom the URL we also need to create a .htaccessfile

with the following contents:

%ewrite1ngine on

%ewrite6ond 7 +89inde;.php


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file/codeigniter/application/config/autoload.php. $rom line )* you should

see the following:

/*

default?>password? >5&))#%3?

db>default?>database? tutorial

db>default?>dbdriver? mysHl

db>default?>dbprefi?

db>default?>pconnect? $%D1

db>default?>db!debug? $%D1db>default?>cache!on? &')1

db>default?>cachedir?

db>default?>char!set? utfE

db>default?>dbcollat? utfE!general!ci

db>default?>swap!pre?

db>default?>autoinit? $%D1

db>default?>stricton? &')1

ow that Code/gniter knows how to access our dataase and user tale, we

can no go ahead and create a model which will represent a user.

/**

* Includes the Dser!2odel class as well as the reHuired sub-classes

* JpacKage codeigniter.application.models*/

/**

* Dser!2odel etends codeigniters base 6I!2odel to inherit all

codeigniter magic+

* Jauthor 'eon %evill

* JpacKage codeigniter.application.models

*/

classDser!2odeletends6I!2odel


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L

/*

* & private variable to represent each column in the database

*/

private!id

private!username

private!password

function !!construct9=

L

parent::!!construct9=

M

/*

* )1$s N (1$s

* )ets and gets allow you to retrieve or set a private

variable on an obOect

*/

/**

I3

**/

/**

* Jreturn int >this-P!id? %eturn this obOects I3

*/

publicfunction getId9=L

returnthis-P!id

M

/**

* Jparam int Integer to set this obOects I3 to

*/

publicfunction setId9value=L


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this-P!id value

M

/**

D)1%"&21

**/

/**

* Jreturn string >this-P!username? %eturn this obOects

username

*/

publicfunction getDsername9=

L

returnthis-P!username

M

/**

* Jparam string )tring to set this obOects username to

*/

publicfunction setDsername9value=

L

this-P!username value

M

/**

5&))#%3

**/

/**

* Jreturn string >this-P!password? %eturn this obOects

password

*/

publicfunction get5assword9=

L

returnthis-P!password

M


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/**

* Jparam string )tring to set this obOects password to

*/

publicfunction set5assword9value=

L

this-P!password value

M

/*

* 6lass 2ethods

*/

/**

* 6ommit method, this will comment the entire obOect to

the database

*/

publicfunction commit9=

L

data array9

usernameP this-P!username,

passwordP this-P!password

=

if9this-P!id P 0= L

//e have an I3 so we need to update this

obOect because it is not new

if9this-Pdb-Pupdate9user, data, array9id

P this-P!id=== Lreturntrue

M

M elseL

//e dont have an I3 meaning it is new and not

yet in the database so we need to do an insert

if9this-Pdb-Pinsert9user, data== L

//"ow we can get the I3 and update the

newly created obOectthis-P!id this-Pdb-Pinsert!id9=


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returntrue

M

M

returnfalse

M

M

Save the aove code as a file called user_model.phpwithin

the/codeigniter/application/modelsdirectory.

+nd that is all there is to a model- The aove code is well commented andshould make sense ut lets go over it section y section. Lets start with the

private variales.

R/1+T@ 1+R/+7L@S

private !id

private !username

private !password

These variales simple provide a place for us to store the data from their

matching column in the dataase, you can call them anything you like ut it

makes sense to call them the same thing as the dataase column to avoid

confusion.

S@TS A B@TS

public function getDsername9=

L

return this-P!id

M


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public function setDsername9value=

L

this-P!username value

M

ou can look at sets and gets as an interface to the o2ect that the model is

representing. =e have private variales as opposed to pulic so that they

cannot e modified outside the models scope. This allows us to use set and get

methods to control what can e set and what can e got from these private

variales. $or e9ample, you could always cast to integer to ensure that a private

variale would always e so, something you could not do if you were e9posing

the local variales to the outside world. +nother e9ample is if one of these

private variales was a date, you could ensure that a formatted date was

always provided via the get method for this variale, saving formatting the value

every time you needed it.

C(00/T/B T4@ (7D@CT

public function commit9=

L

data array9

username P this-P!username,

password P this-P!password

=

if 9this-P!id P 0= L

//e have an I3 so we need to update this

obOect because it is not new

if 9this-Pdb-Pupdate9user, data, array9id

P this-P!id=== L

return true

M

M else L


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//e dont have an I3 meaning it is new and not

yet in the database so we need to do an insert

if 9this-Pdb-Pinsert9user, data== L

//"ow we can get the I3 and update the

newly created obOect

this-P!id this-Pdb-Pinsert!id9=

return true

M

M

return false

M

(viously at some point we are going to want to save the o2ect&s data ack to

the dataase. =e create a method called commit which simply does that. This

method checks to see if it has an />, if it does then an entry for this o2ect

already e9ists within the dataase. /f the o2ect already e9ists in the dataase

then it needs to perform an update. /f the o2ect doesn&t already have an /> then

it does not currently have a dataase entry. /f there is no entry it needs to create

a new one and then, using the myS8L function insert_id!which returns the />

of the last inserted row# to then update the o2ect so it will then only perform

updates and not insert a new entry every time a commit is performed.

0(>@L $+CT(R

=e are going to create a very simple factory which is asically a collection of

methods within a lirary that we can reuse to create o2ects with our model.

This separates out methods such as getUser, createUser, etcfrom within the

model, ensuring that the model can strictly represent the dataase row. Take a

look at the following code:

if 9 + defined9A&)15&$== eit9"o direct script access allowed=

class Dseractory L


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private !ci

function !!construct9=

L

//hen the class is constructed get an instance of codeigniter

so we can access it locally

this-P!ci N get!instance9=

//Include the user!model so we can use it

this-P!ci-Pload-Pmodel9user!model=

M

public function getDser9id 0= L

//&re we getting an individual user or are we getting them all

if 9id P 0= L

//(etting an individual user

Huery this-P!ci-Pdb-Pget!where9user, array9id

P id==

//6hecK if any results were returned

if 9Huery-Pnum!rows9= P 0= L

//5ass the data to our local function to create

an obOect for us and return this new obOect

return this-Pcreate#bOectrom3ata9Huery-

Prow9==

M

return false

M else L

//(etting all the users Huery this-P!ci-Pdb-Pselect9*=-Pfrom9user=-

Pget9=



//6reate an array to store users

users array9=

//'oop through each row returned from the Huery

foreach 9Huery-Presult9= as row= L


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L

//hen the class is constructed get an instance of codeigniter

so we can access it locally

this-P!ci N get!instance9=

//Include the user!model so we can use it

this-P!ci-Pload-Pmodel9user!model=

M

4ere we are creating a private variale called $_ci, short for codeigniterwhich

is where we are going to store an instance of codeigniterso we have access to

all its resources. The reason codeigniteris like this is ecause you may want

to create liraries that do not re'uire any of the codeigniterfunctionality

therefore why include the e9tra ulkE Codeigniteris very lean rememer-

Learn more aout creating liraries in codeigniterhere.

Then, within the__construct!of the lirary !which is called when the class is

instantiated# we gra this codeigniterinstance and store it in this variale. ow

we can access all of codeigniter&s magic, for e9ample: $this"#_ci"#db"

#select%&!"#fromuser&!"#get!'

=e have two methods within our factory, the main method is get user:

public function getDser9id 0= L

//&re we getting an individual user or are we getting them all

if 9id P 0= L

//(etting an individual user

Huery this-P!ci-Pdb-Pget!where9user, array9id

P id==



//5ass the data to our local function to create

an obOect for us and return this new obOect

return this-Pcreate#bOectrom3ata9Huery-

Prow9==
http://ellislab.com/codeigniter/user-guide/general/creating_libraries.htmlhttp://ellislab.com/codeigniter/user-guide/general/creating_libraries.html


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M

return false

M else L

//(etting all the users

Huery this-P!ci-Pdb-Pselect9*=-Pfrom9user=-

Pget9=




users array9=



//5ass the row data to our local

function which creates a new user obOect with the data provided and

add it to the users array

users>? this-

Pcreate#bOectrom3ata9row=

M

//%eturn the users array

return users

M

return false

M

M

This method allows us to pass a parameter of $idso we can retrieve a specific

user o2ect, or if we do not provide an /> it will get all of the user o2ects for us.Lets walk through the more complicated side of this method, getting all users:

//(etting all the users

Huery this-P!ci-Pdb-Pselect9*=-Pfrom9user=-Pget9=




users array9=


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//5ass the row data to our local function which

creates a new user obOect with the data provided and add it to the

users array

users>? this-Pcreate#bOectrom3ata9row=

M

//%eturn the users array

return users

M

return false

$irstly we 'uery the user tale and return all rows !$(uery ) $this"#_ci"#db"

#select%&!"#fromuser&!"#get!'#. =e then check to see if there are any

results using the $(uery"#num_rows!method which will return the numer of

results. /f the numer is F then we return false and end e9ecution. /f the numer

of rows is greater than F then we create an array called usersand then loop

through every row returned in the 'uery: foreach $(uery"#result! as $row! *.

$or each returned row we then call our local method:

public function create#bOectrom3ata9row= L

//6reate a new user!model obOect

user new Dser!2odel9=

//)et the I3 on the user model

user-PsetId9row-Pid=

//)et the username on the user model

user-PsetDsername9row-Pusername=

//)et the password on the user model

user-Pset5assword9row-Ppassword=

//%eturn the new user obOect

return user

M


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This method takes the row data and creates a new user o2ect using the

user"model class we created earlier. /t then sets the appropriate values from

the dataase row onto this o2ect and then returns the o2ect to the calling

method.

(nce the calling method receives the new o2ect it adds it to the $usersarray.

(nce it has iterated through each of the returned rows it returns

the $usersarray. Simple-

ow we have a way of representing a dataase row using a model and a way to

get a set of o2ects represented y the codeignitermodel using a lirary, letsmove on to something you can see-

+lease note that the user factory needs to be saed within

the/codeigniter/application/librariesdirectory.

CONTROLLERS

+ controller decides what to display and how to display it. =ithin

the/codeingiter/application/controllerscreate a file called users, which looks

like this:

if 9 + defined9A&)15&$== eit9"o direct script access allowed=

class Dsers etends 6I!6ontroller L

public function inde9=

L

echo $his is the inde+

M

public function show9userId 0=

L

userId 9int=userId


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echo $his is show users+

if 9userId P 0= L

echo Dser I3: LuserIdM

M

M

M

This is not the final version of our controller, we are 2ust going to use this to

demonstrate and help you understand how the controllers in codeigniterwork.

/f you navigate to your site, lets say the URL you are using

is http-//localhost-/, then navigate to: http-//localhost-/usersand

you should see the following:

The indexmethod within the controller is what the controller will fall ack on if

there has een no other method specified within the URL, so ecause we 2ust

went to/usersthe inde9 method is called. ow, navigate

to: http-//localhost-/users/showand you should see the following:


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4ere you can see that y specifying showas the second URL section we are

calling the show method within the controller. ow, navigate

to: http-//localhost-/users/show/0and see the following:

=ith the third section we have passed in a user /> which the show method

picks up and displays on the screen. =e can pass any numer of parameters to

a codeignitercontroller method. ow you understand

how codeigniterscontrollers work we can move on and make the users

controller a little more practical.

Change the show method to look like elow:


L

//&lways ensure an integer

userId 9int=userId


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//'oad the user factory

this-Pload-Plibrary9Dseractory=

//6reate a data array so we can pass information to the

view

data array9

users P this-Puserfactory-PgetDser9userId=

=

//3ump out the data array

var!dump9data=

M

+s always the code is well commented so it should e easy to follow. The main

thing that this method is doing now, is loading the user factory so we can

retrieve user o2ects using the lirary and model we created earlier. =e store

the results within an array which we will eventually pass to a view and then 2ust

for now we are dumping the results so we can see how they look. Bo ahead

and navigate to: http-//localhost-/users/showand you should see the

following:

array97= L >users?P array94= L >0?P obOect9Dser!2odel=QCC 9R=

L >!id:Dser!2odel:private?P string97= 7

>!username:Dser!2odel:private?P string9S= (andalf

>!password:Dser!2odel:private?P string9T= iamwhite+ M >7?P

obOect9Dser!2odel=QCR 9R= L >!id:Dser!2odel:private?P string97=

C >!username:Dser!2odel:private?P string9U= Ailbo

>!password:Dser!2odel:private?P string970= bagginses+ M >C?P

obOect9Dser!2odel=QC4 9R= L >!id:Dser!2odel:private?P string97=

R >!username:Dser!2odel:private?P string9V= (ollum

>!password:Dser!2odel:private?P string9E= precious M >R?P

obOect9Dser!2odel=QCU 9R= L >!id:Dser!2odel:private?P string97=

4 >!username:Dser!2odel:private?P string9U= arwen

>!password:Dser!2odel:private?P string97U=

tolodannangalad M M M


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The aove output is a dump of an array of user models which are presenting

every user within our user tale, if you navigate

to: http-//localhost-/users/show/0and view the following output:

array97= L >users?P obOect9Dser!2odel=Q7T 9R=

L >!id:Dser!2odel:private?P string97= 7

>!username:Dser!2odel:private?P string9S= (andalf

>!password:Dser!2odel:private?P string9T= iamwhite+ M M

ou can see that the results are 2ust for the user with user /> ; as this is whatwe have specified within the URL, try changing the user /> and see what

happens.

ow you should have a pretty good understanding as to how we can re'uest

and retrieve data from the dataase in a complete o2ect oriented manner. Lets

move onto the final section and create some views-

VIEWS

+ view is simple how the data is presented to the user, typically consisting of the

4T0L and other client side code. =e are going to create a view which will take

the data array we created in our controller in the previous section and list out all

the users it is given. =ithin/codeingiter/application/iewscreate a file

called show_users.phpwith the following code:

//6hecK to see if users could be found

if 9users + &')1= L

//6reate the $2' table header

echo WWW$2'

Wtable border7P


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WtrP

WthPI3 QW/thP

WthPDsernameW/thP

WthP5asswordW/thP

W/trP

$2'

//3o we have an array of users or Oust a single user

obOectX

if 9is!array9users= NN count9users== L

//'oop through all the users and create a row

for each within the table

foreach 9users as user= L

echo WWW$2'

WtrP

WtdPLuser-PgetId9=MW/tdP

WtdPLuser-

PgetDsername9=MW/tdP

WtdPLuser-

Pget5assword9=MW/tdP

W/trP

$2'

M

M else L

//#nly a single user obOect so Oust create onerow within the table

echo WWW$2'

WtrP

WtdPLusers-

PgetId9=MW/tdP

WtdPLusers-

PgetDsername9=MW/tdP


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WtdPLusers-

Pget5assword9=MW/tdP

W/trP

$2'

M

//6lose the table $2'

echo WWW$2'

W/tableP

$2'

M else L

//"ow user could be found so display an error messsage

to the user

echo WWW$2'

WpP& user could not be found with the specified

user I3Q, please try again.W/pP

$2'

M

7efore we take a look at this code in any detail, we need to update our

controller to load the view and provide it with the user data it needs. Change the

show method within the users controller to e as follows:


L

//&lways ensure an integer

userId 9int=userId

//'oad the user factory

this-Pload-Plibrary9Dseractory=

//6reate a data array so we can pass information to the

view

data array9


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users P this-Puserfactory-PgetDser9userId=

=

//'oad the view and pass the data to it

this-Pload-Pview9show!users, data=

M

+ll we have changed is we are now using this codeigniterload functionality

!$this"#load"#iew!# to load the view we have created. The first parameter is

the name of the file within the views directory we want to load, the second is an

array of data we want to pass to the view. ote that any key within

the $dataarray will ecome a variale within the view. So in this e9ample to

access the $data12users23value, we simple use $userswithin the view.

ow we have the controller loading the view and we understand how to access

the data we have passed to it from within the view, lets walk through the code.

$irstly we check to see if the Gusers variale is not false, if the factory cannot

find a user with the specified /> then it will return false. =e handle this and then

display an error message to the user: 5+ user could not e found with the

specified user />H, please try again.6.

/f the Gusers variale is not false and has some data we then need to check to

see if it is a single user !an /> has een specified# or it is an array of multiple

users. /f it is multiple users we then loop through each user and create a row

with their data within the 4T0L tale.

if it is 2ust a single user then we 2ust create a single row with the user data.

Simple, as, that-

CONCLUSION

ow you have completed this codeigniter tutorialyou should now have a good

understanding of how codeigniterworks. ou should know how to set%


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up codeigniterincluding all the configuration, create models, views and

controllers along with liraries and know how to load and use them successfully

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