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• PHP Passing Data to a Specific Class? (Data Encapsulation)

  - by Adam184

  I've learned that OOP is all about data encapsulation, but what about passing data between classes that have nothing to do with each other (would the below example be worthy of using extends)? class Dog { private $secretVar; public function getSecretVar() { $this->secretVar = 'psst... only for rainbow!'; return $this->secretVar; } } class Rainbow { public function __construct(Dog $Dog) { print_r($Dog->getSecretVar()); } } $Dog = new Dog(); $Rainbow = new Rainbow($Dog); // ... classes that don't need the $secretVar How would you encapsulate $secretVar for only classes Dog and Rainbow? As of now, anyone can call getSecretVar(), and I'm having a hard time allowing that to happen as it seems to defeat the whole point of encapsulation.

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• What is the difference between polymorphism and encapsulation ? [closed]

  - by anu

  I want to know the difference between polymorphism and encapsulation. Can you please explain with a legibly good example.

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• Vlans and subinterfaces

  - by Adeodatus

  I've inherited a moderate size network that I'm trying to bring some sanity to. Basically, its 8 public class Cs and a slew of private ranges all on one vlan (vlan1, of course). Most of the network is located throughout dark sites. I need to start separating some of the network. I've changed the ports from the main cisco switch (3560) to the cisco router (3825) and the other remote switches to trunking with dot1q encapsulation. I'd like to start moving a few select subnets to different vlans. To get some of the different services provided on our address space (and to separate customers) on to different vlans, do I need to create a subinterface on the router for each vlan and, if so, how do I get the switch port to work on a specific vlan? Keep in mind, these are dark sites and geting console access is difficult if not impossible at the moment. I was planning on creating a subinterface on the router for each vlan then setting the ports with services I want to move to a different vlan to allow only that vlan. Example of vlan3: 3825: interface GigabitEthernet0/1.3 description Vlan-3 encapsulation dot1Q 3 ip address 192.168.0.81 255.255.255.240 the connection between the switch and router: interface GigabitEthernet0/48 description Core-router switchport trunk encapsulation dot1q switchport mode trunk show interfaces gi0/48 switchport Name: Gi0/48 Switchport: Enabled Administrative Mode: trunk Operational Mode: trunk Administrative Trunking Encapsulation: dot1q Operational Trunking Encapsulation: dot1q Negotiation of Trunking: On Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) Administrative Native VLAN tagging: enabled Voice VLAN: none Administrative private-vlan host-association: none Administrative private-vlan mapping: none Administrative private-vlan trunk native VLAN: none Administrative private-vlan trunk Native VLAN tagging: enabled Administrative private-vlan trunk encapsulation: dot1q Administrative private-vlan trunk normal VLANs: none Administrative private-vlan trunk private VLANs: none Operational private-vlan: none Trunking VLANs Enabled: ALL Pruning VLANs Enabled: 2-1001 Capture Mode Disabled Capture VLANs Allowed: ALL Protected: false Unknown unicast blocked: disabled Unknown multicast blocked: disabled Appliance trust: none So, if the boxen hanging off of gi0/18 on the 3560 are on an unmanaged layer2 switch and all within the 192.168.0.82-95 range and are using 192.168.0.81 as their gateway, what is left to do, especially to gi0/18, to get this working on vlan3? Are there any recommendations for a better setup without taking everything offline?

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• Java: reusable encapsulation with interface, abstract class or inner classes?

  - by HH

  I try to encapsulate. Exeption from interface, static inner class working, non-static inner class not working, cannot understand terminology: nested classes, inner classes, nested interfaces, interface-abstract-class -- sounds too Repetitive! Exception 'illegal type' from interface apparently because values being constants(?!) static interface userInfo { File startingFile=new File("."); String startingPath="dummy"; try{ startingPath=startingFile.getCanonicalPath(); }catch(Exception e){e.printStackTrace();} } Working code but no succes with non-static inner class import java.io.*; import java.util.*; public class listTest{ public interface hello{String word="hello word from Interface!";} public static class hej{ hej(){} private String hejo="hello hallo from Static class with image"; public void printHallooo(){System.out.println(hejo);} } public class nonStatic{ nonStatic(){} //HOW TO USE IT? public void printNonStatic(){System.out.println("Inside static class with an image!");} } public static void main(String[] args){ //INTERFACE TEST System.out.println(hello.word); //INNNER CLASS STATIC TEST hej h=new hej(); h.printHallooo(); //INNER CLASS NON-STATIC TEST nonStatic ns=new nonStatic(); ns.printNonStatic(); //IS there a way to it without STATIC? } } Output The above code works but how non-staticly? Output: hello word from Interface! hello hallo from Static class with image! StaticPrint without an image of the class! Related Nesting classes inner classes? interfacses

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• Tunneling in IPv6:

  - by JoesyXHN

  Hi, The concept of 6to4 tunneling is to do encapsulate and descapsulate an ipv6 packet through ipv4 network. The encapsulation process is: [IPv6 header][Transport Header][Application Protocol data] = encapsulation: [Ip4 Header][IPv6 header][Transport Header][Application Protocol data] I am talking from this infrastructure: Host A (IPv6) - Router R1 (dual stack) - Ipv4 net work - Router R2 (dual stack) - Host B (Ipv6) packet. The Ipv4 header in the encapsulation, which Ipv4 header is this among: Host A, Router R1, Router R2 and Host B? Thanks in advance.

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• Configuring CESoPSN using Cisco MWR 2941

  - by Rayne

  I'm trying to configure CESoPSN on two Cisco MWR 2941 routers, but the alarm LED lights are always lit. My configuration is modeled after this sample configuration. My setup is as follows: On the Cisco MWRs, E1 0/5 is configured to be CESoPSN, E1 0/9 is configured to be CESoPSN (CAS mode), and E1 0/7 is configured to be SAToP. The two MWRs are connected to each other via the GigabitEthernet port 0/2. The GigE ports are configured as a vlan because the ports are L2 ports and cannot be assigned an IP address directly. The two Cisco MWRs are connected to a traffic simulator, i.e. the traffic simulator will play out E1 traffic to MWR 1 and record the output traffic from MWR 2. On my traffic simulator, when it's connected to the E1 ports 0/5 and 0/9 (both CESoPSN configurations), the "Remote" alarm is on. However, when connected to the E1 ports 0/7 (SAToP configuration), no alarms were on. The GigE connection seems to be working fine (both LED lights on the 2 ports are green). The SAToP configuration seems to be fine too (Left LED is green, right LED is off on both E1 0/7 ports). However, both CESoPSN configurations seem to be not working (Left LED is green, right LED is yellow on both E1 0/5 and 0/9 ports). I don't know if there's anything wrong with my configuration for the CESoPSN, as I'm very new to this. The relevant portions of the configuration are as follows: MWR 1: controller E1 0/5 clock source internal cem-group 5 timeslots 1-31 description E1 CESoPSN example ! controller E1 0/7 clock source internal cem-group 7 unframed description E1 SATOP example ! controller E1 0/9 mode cas clock source internal cem-group 9 timeslots 1-24 description E1 CESoPSN CAS example ! interface Loopback0 ip address 30.30.30.1 255.255.255.255 ! interface GigabitEthernet0/2 switchport access vlan 100 mpls ip ! interface CEM0/5 no ip address cem 5 xconnect 30.30.30.2 305 encapsulation mpls ! ! interface CEM0/7 no ip address cem 7 xconnect 30.30.30.2 307 encapsulation mpls ! ! interface CEM0/9 no ip address cem 9 signaling inband-cas xconnect 30.30.30.2 309 encapsulation mpls ! ! interface Vlan100 ip address 50.50.50.1 255.255.255.0 no ptp enable mpls ip ! no ip classless ip forward-protocol nd ip route 30.30.30.2 255.255.255.255 50.50.50.2 ! MWR 2: controller E1 0/5 clock source internal cem-group 5 timeslots 1-31 description E1 CESoPSN example ! controller E1 0/7 clock source internal cem-group 7 unframed ! controller E1 0/9 mode cas clock source internal cem-group 9 timeslots 1-24 description E1 CESoPSN CAS example ! interface Loopback0 ip address 30.30.30.2 255.255.255.255 ! interface GigabitEthernet0/2 switchport access vlan 100 mpls ip ! interface CEM0/5 no ip address cem 5 xconnect 30.30.30.1 305 encapsulation mpls ! ! interface CEM0/7 no ip address cem 7 xconnect 30.30.30.1 307 encapsulation mpls ! ! interface CEM0/9 no ip address cem 9 signaling inband-cas xconnect 30.30.30.1 309 encapsulation mpls ! ! interface Vlan100 ip address 50.50.50.2 255.255.255.0 no ptp enable mpls ip ! no ip classless ip forward-protocol nd ip route 30.30.30.1 255.255.255.255 50.50.50.1 ! If anyone is familiar with CESoPSN configurations, please advise.

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• Can't configure frame relay T1 on Cisco 1760

  - by sonar

  For the past few days I've been trying to configure a data T1 via a Frame Relay. Now I've been pretty unsuccessful at it, and it's been a while, since I've done this so please bare with me. The ISP provided me the following information: 1. IP address 2. Gateway address 3. Encapsulation Frame Relay 4. DLCI 100 5. BZ8 ESF (I think the bz8 was supposed to be b8zs) 6. Time Slot (1 al 24). And what I have configured up until now is the following: interface Serial0/0 ip address <ip address> 255.255.255.252 encapsulation frame-relay service-module t1 timeslots 1-24 frame-relay interface-dlci 100 sh service-module s0/0 (outputs): Module type is T1/fractional Hardware revision is 0.128, Software revision is 0.2, Image checksum is 0x73D70058, Protocol revision is 0.1 Receiver has no alarms. Framing is **ESF**, Line Code is **B8ZS**, Current clock source is line, Fraction has **24 timeslots** (64 Kbits/sec each), Net bandwidth is 1536 Kbits/sec. Last module self-test (done at startup): Passed Last clearing of alarm counters 00:17:17 loss of signal : 0, loss of frame : 0, AIS alarm : 0, Remote alarm : 2, last occurred 00:10:10 Module access errors : 0, Total Data (last 1 15 minute intervals): 0 Line Code Violations, 0 Path Code Violations 0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins 0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs Data in current interval (138 seconds elapsed): 0 Line Code Violations, 0 Path Code Violations 0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins 0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs sh int: FastEthernet0/0 is up, line protocol is up Hardware is PQUICC_FEC, address is 000d.6516.e5aa (bia 000d.6516.e5aa) Internet address is 10.0.0.1/24 MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 100Mb/s, 100BaseTX/FX ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:20:00, output 00:00:00, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog 0 input packets with dribble condition detected 191 packets output, 20676 bytes, 0 underruns 0 output errors, 0 collisions, 1 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out Serial0/0 is up, line protocol is down Hardware is PQUICC with Fractional T1 CSU/DSU MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation FRAME-RELAY, loopback not set Keepalive set (10 sec) LMI enq sent 157, LMI stat recvd 0, LMI upd recvd 0, DTE LMI down LMI enq recvd 23, LMI stat sent 0, LMI upd sent 0 LMI DLCI 1023 LMI type is CISCO frame relay DTE FR SVC disabled, LAPF state down Broadcast queue 0/64, broadcasts sent/dropped 2/0, interface broadcasts 0 Last input 00:24:51, output 00:00:05, output hang never Last clearing of "show interface" counters 00:27:20 Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: weighted fair Output queue: 0/1000/64/0 (size/max total/threshold/drops) Conversations 0/1/256 (active/max active/max total) Reserved Conversations 0/0 (allocated/max allocated) Available Bandwidth 1152 kilobits/sec 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 23 packets input, 302 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 1725 input errors, 595 CRC, 1099 frame, 0 overrun, 0 ignored, 30 abort 246 packets output, 3974 bytes, 0 underruns 0 output errors, 0 collisions, 48 interface resets 0 output buffer failures, 0 output buffers swapped out 4 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up Serial0/0.1 is down, line protocol is down Hardware is PQUICC with Fractional T1 CSU/DSU MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation FRAME-RELAY Last clearing of "show interface" counters never Serial0/0.100 is down, line protocol is down Hardware is PQUICC with Fractional T1 CSU/DSU Internet address is <ip address>/30 MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation FRAME-RELAY Last clearing of "show interface" counters never And everything seems to be accounted for to me, but apparently I'm missing something. My issue is that I'm stuck on interface up, line protocol down, so the T1 doesn't go up. Any ideas? Thank you,

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• JavaScript Class Patterns &ndash; In CoffeeScript

  - by Liam McLennan

  Recently I wrote about JavaScript class patterns, and in particular, my favourite class pattern that uses closure to provide encapsulation. A class to represent a person, with a name and an age, looks like this: var Person = (function() { // private variables go here var name,age; function constructor(n, a) { name = n; age = a; } constructor.prototype = { toString: function() { return name + " is " + age + " years old."; } }; return constructor; })(); var john = new Person("John Galt", 50); console.log(john.toString()); Today I have been experimenting with coding for node.js in CoffeeScript. One of the first things I wanted to do was to try and implement my class pattern in CoffeeScript and then see how it compared to CoffeeScript’s built-in class keyword. The above Person class, implemented in CoffeeScript, looks like this: # JavaScript style class using closure to provide private methods Person = (() -> [name,age] = [{},{}] constructor = (n, a) -> [name,age] = [n,a] null constructor.prototype = toString: () -> "name is #{name} age is #{age} years old" constructor )() I am satisfied with how this came out, but there are a few nasty bits. To declare the two private variables in javascript is as simple as var name,age; but in CoffeeScript I have to assign a value, hence [name,age] = [{},{}]. The other major issue occurred because of CoffeeScript’s implicit function returns. The last statement in any function is returned, so I had to add null to the end of the constructor to get it to work. The great thing about the technique just presented is that it provides encapsulation ie the name and age variables are not visible outside of the Person class. CoffeeScript classes do not provide encapsulation, but they do provide nicer syntax. The Person class using native CoffeeScript classes is: # CoffeeScript style class using the class keyword class CoffeePerson constructor: (@name, @age) -> toString: () -> "name is #{@name} age is #{@age} years old" felix = new CoffeePerson "Felix Hoenikker", 63 console.log felix.toString() So now I have a trade-off: nice syntax against encapsulation. I think I will experiment with both strategies in my project and see which works out better.

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• Combinatorial explosion of interfaces: How many is too many?

  - by mga

  I'm a relative newcomer to OOP, and I'm having a bit of trouble creating good designs when it comes to interfaces. Consider a class A with N public methods. There are a number of other classes, B, C, ..., each of which interacts with A in a different way, that is, accesses some subset (<= N) of A's methods. The maximum degree of encapsulation is achieved by implementing an interface of A for each other class, i.e. AInterfaceForB, AInterfaceForC, etc. However, if B, C, ... etc. also interact with A and with each other, then there will be a combinatorial explosion of interfaces (a maximum of n(n-1), to be precise), and the benefit of encapsulation becomes outweighed by a code-bloat. What is the best practice in this scenario? Is the whole idea of restricting access to a class's public functions in different ways for other different classes just silly altogether? One could imagine a language that explicitly allows for this sort of encapsulation (e.g. instead of declaring a function public, one could specify exactly which classes it is visible to); Since this is not a feature of C++, maybe it's misguided to try to do it through the back door with interaces?

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• Trying to configure HWIC-3G-HSPA

  - by user1174838

  I'm trying to configure a couple of Cisco 1941 routes. The are both identical routers. Each as a HWIC-1T (Smart Serial interface) and a HWIC-3G-HSPA 3G interface. These routers are to be sent to remote sites. We have connectivity to one of the sites but if remote site A gors down we lose connectivity to remote site B. The HWIC-1T is the primary WAN interface using frame relay joining the two remote sites We want the HWIC-3G-HSPA to be usable for direct connectivity from head office to remote site B, and also the HWIC-3G-HSPA is do be used for comms between the remote sites when the frame relay is down (happens quite a bit). I initialy tried to do dynamic routing using EIGRP however in my lab setup of laptop - 1941 - 1941 - laptop, I was unable to get end to end connectivity. I later settled on static routing and have got end to end connectivity but only over frame relay, not the HWIC-3G-HSPA. The sanitized running config for remote site A: version 15.1 service tcp-keepalives-in service tcp-keepalives-out service timestamps debug datetime msec service timestamps log datetime msec service password-encryption service udp-small-servers service tcp-small-servers ! hostname remoteA ! boot-start-marker boot-end-marker ! ! logging buffered 51200 warnings enable secret 5 censored ! no aaa new-model clock timezone wst 8 0 ! no ipv6 cef ip source-route ip cef ! ip domain name yourdomain.com multilink bundle-name authenticated ! chat-script gsm "" "ATDT*98*1#" TIMEOUT 30 "CONNECT" ! username admin privilege 15 secret 5 censored ! controller Cellular 0/1 ! interface Embedded-Service-Engine0/0 no ip address shutdown ! interface GigabitEthernet0/0 ip address 192.168.2.5 255.255.255.0 duplex auto speed auto ! interface GigabitEthernet0/1 no ip address shutdown duplex auto speed auto ! interface Serial0/0/0 ip address 10.1.1.2 255.255.255.252 encapsulation frame-relay cdp enable frame-relay interface-dlci 16 frame-relay lmi-type ansi ! interface Cellular0/1/0 ip address negotiated encapsulation ppp dialer in-band dialer idle-timeout 2147483 dialer string gsm dialer-group 1 async mode interactive ppp chap hostname censored ppp chap password 7 censored cdp enable ! interface Cellular0/1/1 no ip address encapsulation ppp ! interface Dialer0 no ip address ! ip forward-protocol nd ! no ip http server no ip http secure-server ! ip route 0.0.0.0 0.0.0.0 Serial0/0/0 210 permanent ip route 0.0.0.0 0.0.0.0 Cellular0/1/0 220 permanent ip route 172.31.2.0 255.255.255.0 Cellular0/1/0 permanent ip route 192.168.3.0 255.255.255.0 10.1.1.1 permanent ip route 192.168.3.0 255.255.255.0 Cellular0/1/0 210 permanent ! access-list 1 permit any dialer-list 1 protocol ip list 1 ! control-plane ! line con 0 logging synchronous login local line aux 0 line 2 no activation-character no exec transport preferred none transport input all transport output pad telnet rlogin lapb-ta mop udptn v120 ssh stopbits 1 line 0/1/0 exec-timeout 0 0 script dialer gsm login modem InOut no exec transport input all rxspeed 7200000 txspeed 5760000 line 0/1/1 no exec rxspeed 7200000 txspeed 5760000 line vty 0 4 access-class 23 in privilege level 15 password 7 censored login local transport input all line vty 5 15 access-class 23 in privilege level 15 password 7 censored login local transport input all line vty 16 1370 password 7 censored login transport input all ! scheduler allocate 20000 1000 end The sanitized running config for remote site B: version 15.1 service tcp-keepalives-in service tcp-keepalives-out service timestamps debug datetime msec service timestamps log datetime msec service password-encryption service udp-small-servers service tcp-small-servers ! hostname remoteB ! boot-start-marker boot-end-marker ! logging buffered 51200 warnings enable secret 5 censored ! no aaa new-model clock timezone wst 8 0 ! no ipv6 cef ip source-route ip cef ! no ip domain lookup ip domain name yourdomain.com multilink bundle-name authenticated ! chat-script gsm "" "ATDT*98*1#" TIMEOUT 30 "CONNECT" username admin privilege 15 secret 5 censored ! controller Cellular 0/1 ! interface Embedded-Service-Engine0/0 no ip address shutdown ! interface GigabitEthernet0/0 ip address 192.168.3.1 255.255.255.0 duplex auto speed auto ! interface GigabitEthernet0/1 no ip address shutdown duplex auto speed auto ! interface Serial0/0/0 ip address 10.1.1.1 255.255.255.252 encapsulation frame-relay clock rate 2000000 cdp enable frame-relay interface-dlci 16 frame-relay lmi-type ansi frame-relay intf-type dce ! interface Cellular0/1/0 ip address negotiated encapsulation ppp dialer in-band dialer idle-timeout 2147483 dialer string gsm dialer-group 1 async mode interactive ppp chap hostname censored ppp chap password 7 censored ppp ipcp dns request cdp enable ! interface Cellular0/1/1 no ip address encapsulation ppp ! interface Dialer0 no ip address ! ip forward-protocol nd ! no ip http server no ip http secure-server ! ip route 0.0.0.0 0.0.0.0 Serial0/0/0 210 permanent ip route 0.0.0.0 0.0.0.0 Cellular0/1/0 220 permanent ip route 172.31.2.0 255.255.255.0 Cellular0/1/0 permanent ip route 192.168.2.0 255.255.255.0 10.1.1.2 permanent ip route 192.168.2.0 255.255.255.0 Cellular0/1/0 210 permanent ! kron occurrence PING in 1 recurring policy-list ICMP ! access-list 1 permit any dialer-list 1 protocol ip list 1 ! control-plane ! line con 0 logging synchronous login local line aux 0 line 2 no activation-character no exec transport preferred none transport input all transport output pad telnet rlogin lapb-ta mop udptn v120 ssh stopbits 1 line 0/1/0 exec-timeout 0 0 script dialer gsm login modem InOut no exec transport input all rxspeed 7200000 txspeed 5760000 line 0/1/1 no exec rxspeed 7200000 txspeed 5760000 line vty 0 4 access-class 23 in privilege level 15 password 7 censored login transport input all line vty 5 15 access-class 23 in privilege level 15 password 7 censored login transport input all line vty 16 1370 password 7 censored login transport input all ! scheduler allocate 20000 1000 end The last problem I'm having is the 3G interfaces go down after only a few minutes of inactivity. I've tried using kron to ping the local HWIC-3G-HSPA interface (cellular 0/1/0) every minute but that hasn't been successful. Manually pinging the IP assigned (by the telco) to ce0/1/0 does bring the interface up. Any ideas? Thanks

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• How to measure code quality? [closed]

  - by Lo Wai Lun

  Is there a methodology or any objective standard to determine whether the code of the project is well-written? How to measure in a structural and scientific manner to access the quality of the code? Many people say code review is important and always do encapsulation and data abstraction to ensure the quality. How can we determine the quality? Can a structural, organised software design diagrams drawn implies good quality of code ? If we type the code with good cautions of encapsulation and data abstraction, why review anyway?

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• Is functional programming a superset of object oriented?

  - by Jimmy Hoffa

  The more functional programming I do, the more I feel like it adds an extra layer of abstraction that seems like how an onion's layer is- all encompassing of the previous layers. I don't know if this is true so going off the OOP principles I've worked with for years, can anyone explain how functional does or doesn't accurately depict any of them: Encapsulation, Abstraction, Inheritance, Polymorphism I think we can all say, yes it has encapsulation via tuples, or do tuples count technically as fact of "functional programming" or are they just a utility of the language? I know Haskell can meet the "interfaces" requirement, but again not certain if it's method is a fact of functional? I'm guessing that the fact that functors have a mathematical basis you could say those are a definite built in expectation of functional, perhaps? Please, detail how you think functional does or does not fulfill the 4 principles of OOP.

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• Cisco 891w multiple VLAN configuration

  - by Jessica

  I'm having trouble getting my guest network up. I have VLAN 1 that contains all our network resources (servers, desktops, printers, etc). I have the wireless configured to use VLAN1 but authenticate with wpa2 enterprise. The guest network I just wanted to be open or configured with a simple WPA2 personal password on it's own VLAN2. I've looked at tons of documentation and it should be working but I can't even authenticate on the guest network! I've posted this on cisco's support forum a week ago but no one has really responded. I could really use some help. So if anyone could take a look at the configurations I posted and steer me in the right direction I would be extremely grateful. Thank you! version 15.0 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname ESI ! boot-start-marker boot-end-marker ! logging buffered 51200 warnings ! aaa new-model ! ! aaa authentication login userauthen local aaa authorization network groupauthor local ! ! ! ! ! aaa session-id common ! ! ! clock timezone EST -5 clock summer-time EDT recurring service-module wlan-ap 0 bootimage autonomous ! crypto pki trustpoint TP-self-signed-3369945891 enrollment selfsigned subject-name cn=IOS-Self-Signed-Certificate-3369945891 revocation-check none rsakeypair TP-self-signed-3369945891 ! ! crypto pki certificate chain TP-self-signed-3369945891 certificate self-signed 01 (cert is here) quit ip source-route ! ! ip dhcp excluded-address 192.168.1.1 ip dhcp excluded-address 192.168.1.5 ip dhcp excluded-address 192.168.1.2 ip dhcp excluded-address 192.168.1.200 192.168.1.210 ip dhcp excluded-address 192.168.1.6 ip dhcp excluded-address 192.168.1.8 ip dhcp excluded-address 192.168.3.1 ! ip dhcp pool ccp-pool import all network 192.168.1.0 255.255.255.0 default-router 192.168.1.1 dns-server 10.171.12.5 10.171.12.37 lease 0 2 ! ip dhcp pool guest import all network 192.168.3.0 255.255.255.0 default-router 192.168.3.1 dns-server 10.171.12.5 10.171.12.37 ! ! ip cef no ip domain lookup no ipv6 cef ! ! multilink bundle-name authenticated license udi pid CISCO891W-AGN-A-K9 sn FTX153085WL ! ! username ESIadmin privilege 15 secret 5 $1$g1..$JSZ0qxljZAgJJIk/anDu51 username user1 password 0 pass ! ! ! class-map type inspect match-any ccp-cls-insp-traffic match protocol cuseeme match protocol dns match protocol ftp match protocol h323 match protocol https match protocol icmp match protocol imap match protocol pop3 match protocol netshow match protocol shell match protocol realmedia match protocol rtsp match protocol smtp match protocol sql-net match protocol streamworks match protocol tftp match protocol vdolive match protocol tcp match protocol udp class-map type inspect match-all ccp-insp-traffic match class-map ccp-cls-insp-traffic class-map type inspect match-any ccp-cls-icmp-access match protocol icmp class-map type inspect match-all ccp-invalid-src match access-group 100 class-map type inspect match-all ccp-icmp-access match class-map ccp-cls-icmp-access class-map type inspect match-all ccp-protocol-http match protocol http ! ! policy-map type inspect ccp-permit-icmpreply class type inspect ccp-icmp-access inspect class class-default pass policy-map type inspect ccp-inspect class type inspect ccp-invalid-src drop log class type inspect ccp-protocol-http inspect class type inspect ccp-insp-traffic inspect class class-default drop policy-map type inspect ccp-permit class class-default drop ! zone security out-zone zone security in-zone zone-pair security ccp-zp-self-out source self destination out-zone service-policy type inspect ccp-permit-icmpreply zone-pair security ccp-zp-in-out source in-zone destination out-zone service-policy type inspect ccp-inspect zone-pair security ccp-zp-out-self source out-zone destination self service-policy type inspect ccp-permit ! ! crypto isakmp policy 1 encr 3des authentication pre-share group 2 ! crypto isakmp client configuration group 3000client key 67Nif8LLmqP_ dns 10.171.12.37 10.171.12.5 pool dynpool acl 101 ! ! crypto ipsec transform-set myset esp-3des esp-sha-hmac ! crypto dynamic-map dynmap 10 set transform-set myset ! ! crypto map clientmap client authentication list userauthen crypto map clientmap isakmp authorization list groupauthor crypto map clientmap client configuration address initiate crypto map clientmap client configuration address respond crypto map clientmap 10 ipsec-isakmp dynamic dynmap ! ! ! ! ! interface FastEthernet0 ! ! interface FastEthernet1 ! ! interface FastEthernet2 ! ! interface FastEthernet3 ! ! interface FastEthernet4 ! ! interface FastEthernet5 ! ! interface FastEthernet6 ! ! interface FastEthernet7 ! ! interface FastEthernet8 ip address dhcp ip nat outside ip virtual-reassembly duplex auto speed auto ! ! interface GigabitEthernet0 description $FW_OUTSIDE$$ES_WAN$ ip address 10...* 255.255.254.0 ip nat outside ip virtual-reassembly zone-member security out-zone duplex auto speed auto crypto map clientmap ! ! interface wlan-ap0 description Service module interface to manage the embedded AP ip unnumbered Vlan1 arp timeout 0 ! ! interface Wlan-GigabitEthernet0 description Internal switch interface connecting to the embedded AP switchport trunk allowed vlan 1-3,1002-1005 switchport mode trunk ! ! interface Vlan1 description $ETH-SW-LAUNCH$$INTF-INFO-FE 1$$FW_INSIDE$ ip address 192.168.1.1 255.255.255.0 ip nat inside ip virtual-reassembly zone-member security in-zone ip tcp adjust-mss 1452 crypto map clientmap ! ! interface Vlan2 description guest ip address 192.168.3.1 255.255.255.0 ip access-group 120 in ip nat inside ip virtual-reassembly zone-member security in-zone ! ! interface Async1 no ip address encapsulation slip ! ! ip local pool dynpool 192.168.1.200 192.168.1.210 ip forward-protocol nd ip http server ip http access-class 23 ip http authentication local ip http secure-server ip http timeout-policy idle 60 life 86400 requests 10000 ! ! ip dns server ip nat inside source list 23 interface GigabitEthernet0 overload ip route 0.0.0.0 0.0.0.0 10.165.0.1 ! access-list 23 permit 192.168.1.0 0.0.0.255 access-list 100 remark CCP_ACL Category=128 access-list 100 permit ip host 255.255.255.255 any access-list 100 permit ip 127.0.0.0 0.255.255.255 any access-list 100 permit ip 10.165.0.0 0.0.1.255 any access-list 110 permit ip 192.168.0.0 0.0.5.255 any access-list 120 remark ESIGuest Restriction no cdp run ! ! ! ! ! ! control-plane ! ! alias exec dot11radio service-module wlan-ap 0 session Access point version 12.4 no service pad service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname ESIRouter ! no logging console enable secret 5 $1$yEH5$CxI5.9ypCBa6kXrUnSuvp1 ! aaa new-model ! ! aaa group server radius rad_eap server 192.168.1.5 auth-port 1812 acct-port 1813 ! aaa group server radius rad_acct server 192.168.1.5 auth-port 1812 acct-port 1813 ! aaa authentication login eap_methods group rad_eap aaa authentication enable default line enable aaa authorization exec default local aaa authorization commands 15 default local aaa accounting network acct_methods start-stop group rad_acct ! aaa session-id common clock timezone EST -5 clock summer-time EDT recurring ip domain name ESI ! ! dot11 syslog dot11 vlan-name one vlan 1 dot11 vlan-name two vlan 2 ! dot11 ssid one vlan 1 authentication open eap eap_methods authentication network-eap eap_methods authentication key-management wpa version 2 accounting rad_acct ! dot11 ssid two vlan 2 authentication open guest-mode ! dot11 network-map ! ! username ESIadmin privilege 15 secret 5 $1$p02C$WVHr5yKtRtQxuFxPU8NOx. ! ! bridge irb ! ! interface Dot11Radio0 no ip address no ip route-cache ! encryption vlan 1 mode ciphers aes-ccm ! broadcast-key vlan 1 change 30 ! ! ssid one ! ssid two ! antenna gain 0 station-role root ! interface Dot11Radio0.1 encapsulation dot1Q 1 native no ip route-cache bridge-group 1 bridge-group 1 subscriber-loop-control bridge-group 1 block-unknown-source no bridge-group 1 source-learning no bridge-group 1 unicast-flooding bridge-group 1 spanning-disabled ! interface Dot11Radio0.2 encapsulation dot1Q 2 no ip route-cache bridge-group 2 bridge-group 2 subscriber-loop-control bridge-group 2 block-unknown-source no bridge-group 2 source-learning no bridge-group 2 unicast-flooding bridge-group 2 spanning-disabled ! interface Dot11Radio1 no ip address no ip route-cache shutdown ! encryption vlan 1 mode ciphers aes-ccm ! broadcast-key vlan 1 change 30 ! ! ssid one ! antenna gain 0 dfs band 3 block channel dfs station-role root ! interface Dot11Radio1.1 encapsulation dot1Q 1 native no ip route-cache bridge-group 1 bridge-group 1 subscriber-loop-control bridge-group 1 block-unknown-source no bridge-group 1 source-learning no bridge-group 1 unicast-flooding bridge-group 1 spanning-disabled ! interface GigabitEthernet0 description the embedded AP GigabitEthernet 0 is an internal interface connecting AP with the host router no ip address no ip route-cache ! interface GigabitEthernet0.1 encapsulation dot1Q 1 native no ip route-cache bridge-group 1 no bridge-group 1 source-learning bridge-group 1 spanning-disabled ! interface GigabitEthernet0.2 encapsulation dot1Q 2 no ip route-cache bridge-group 2 no bridge-group 2 source-learning bridge-group 2 spanning-disabled ! interface BVI1 ip address 192.168.1.2 255.255.255.0 no ip route-cache ! ip http server no ip http secure-server ip http help-path http://www.cisco.com/warp/public/779/smbiz/prodconfig/help/eag access-list 10 permit 192.168.1.0 0.0.0.255 radius-server host 192.168.1.5 auth-port 1812 acct-port 1813 key ***** bridge 1 route ip

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• Multiple vlans access to shared pbx system

  - by Matt

  I'm new to networking and was looking for some assistance. First off I'm using packet tracer to diagram my scenario as I will be receiving my equipment next week to deploy. Hardware to be used: 2 catalyst 3560 switches all connect to a sonic wall router I have two companies that work in the same office space. I need to keep these companies separate on their own vlan. They will however need to share the phone system. (Packet tracer file uploaded to give those who have the time to see what I put together.) http://dl.dropbox.com/u/86234623/network%20build.pkt Here is my current test scenario: on switch 0 I have: company A on vlan 2 computers 172.16.1.100 and 101 255.255.0.0 FA0/10 FA0/11 company B on vlan 3 computers 172.16.2.102, 255.255.0.0 FA0/12 PBX on a trunk port 172.16.0.5, 255.255.0.0 FA0/5 trunk port on FA0/1 to connect the switches on switch 1 I have: company A on vlan 2 computers 172.16.1.102, 255.255.0.0 company B on vlan 3 computers 172.16.2.100 and 101, 255.255.0.0 trunk port on FA0/1 to connect the switches I can ping the respective computers on the same vlan but cant ping company A to B which is what I want. However neither company can talk (ping) the PBX. Here are the commands I used to configure what I have: switch 0 en conf t vlan 2 name A vlan 3 name B int fa0/10 switchport mode access switchport access vlan 2 int fa0/11 switchport mode access switchport access vlan 2 int fa0/12 switchport mode access switchport access vlan 3 int fa0/5 switchport trunk encapsulation dot1q switchport mode trunk switchport trunk allowed vlan 1-3 int fa0/1 (to connect the switches) switchport trunk encapsulation dot1q switchport mode trunk switchport trunk allowed vlan 1-3 Switch 1 en conf t vlan 2 name A vlan 3 name B int fa0/10 switchport mode access switchport access vlan 3 int fa0/11 switchport mode access switchport access vlan 3 int fa0/12 switchport mode access switchport access vlan 2 int fa0/1 (to connect the switches) switchport trunk encapsulation dot1q switchport mode trunk switchport trunk allowed vlan 1-3

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• VRF Internet Gateway Multiple External IP's 1 Internal IP to AWS

  - by user223903

  Trying to setup VRF for the first time and its not working for me even though I keep reading everything online. IP's are different to real life. I have an Internet connection which I can ping to my router in the current setup below 195.45.73.22 I have a block of ip addresses 195.45.121.0/27 I want to setup multiple VPN's to AWS so need to have multiple external ip's thus the block of IP addresses. I have setup the 2nd and 3rd IP address but can not ping them from external. Any help would be grateful. Bryan ip source-route ! ip vrf Internet rd 1:1 route-target export 1:1 route-target import 1:1 ip vrf AWSSydney1 rd 2:2 route-target export 2:2 route-target import 2:2 route-target import 1:1 ip vrf AWSSydney2 rd 3:3 route-target export 3:3 route-target import 3:3 route-target import 1:1 ip cef no ip domain lookup no ipv6 cef multilink bundle-name authenticated interface FastEthernet0/0 description Vocus Internet no ip address speed 100 full-duplex interface FastEthernet0/0.1 encapsulation dot1Q 1 native ip address 195.45.73.22 255.255.255.252 interface FastEthernet0/0.2 encapsulation dot1Q 2 ip vrf forwarding AWSSydney1 ip address 195.45.121.1 255.255.255.224 interface FastEthernet0/0.3 encapsulation dot1Q 3 ip vrf forwarding AWSSydney2 ip address 195.45.121.2 255.255.255.224 interface FastEthernet0/1 description LAN_SIDE ip address 10.0.0.5 255.255.255.0 speed 100 full-duplex no mop enabled ip forward-protocol nd ip route 0.0.0.0 0.0.0.0 195.45.73.21 ip route vrf Internet 0.0.0.0 0.0.0.0 195.45.73.21

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• lacp, cicso 3550, 3560, help with configuration

  - by Flamewires

  Hey all this is a repost from a question I asked on the cisco forums but never got a useful reply. Hey I'm trying to convert the FreeBSD servers at work to dual-gig lagg links from regular gigabit links. Our production servers are on a 3560. I have a small test environment on a 3550. I have achieved fail-over, but am having troubles achieving the speed increase. All servers are running gig intel (em) cards. The configs for the servers are: BSDServer: #!/bin/sh #bring up both interfaces ifconfig em0 up media 1000baseTX mediaopt full-duplex ifconfig em1 up media 1000baseTX mediaopt full-duplex #create the lagg interface ifconfig lagg0 create #set lagg0's protocol to lacp, add both cards to the interface, #and assign it em1's ip/netmask ifconfig lagg0 laggproto lacp laggport em0 laggport em1 ***.***.***.*** netmask 255.255.255.0 The switches are configured as follows: #clear out old junk no int Po1 default int range GigabitEthernet 0/15 - 16 # config ports interface range GigabitEthernet 0/15 - 16 description lagg-test switchport duplex full speed 1000 switchport access vlan 192 spanning-tree portfast channel-group 1 mode active channel-protocol lacp **** switchport trunk encapsulation dot1q **** no shutdown exit interface Port-channel 1 description lagginterface switchport access vlan 192 exit port-channel load-balance src-mac end obviously change 1000's to 100's and GigabitEthernet to FastEthernet for the 3550's config, as that switch has 100Mbit speed ports. With this config on the 3550, I get failover and 92Mbits/sec speed on both links, simultaneously, connecting to 2 hosts.(tested with iperf) Success. However this is only with the "switchport trunk encapsulation dot1q" line. First, I do not understand why I need this, I thought it was only for connecting switches. Is there some other setting which this turns on that is actually responsible for the speed increase? Second, This config does not work on the 3560. I get failover, but not the speed increase. Speeds drop from gig/sec to 500Mbit/sec when I make 2 simultaneous connections to the server with or without the encapsulation line. I should mention that both switches are using source-mac load balancing. In my test I am using Iperf. I have the server(lagg box) setup as the server(iperf -s), and the client computers are client(iperf -c server-ip-address), so the source mac(and IP) are different for both connections. Any ideas/corrections/questions would be helpful, as the gig switches are what I actually need the lagg links on. Ask if you need more information.

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• Why do I have to manually 'Restart Management Network' on vSphere 5 host after reboot to get networking available?

  - by growse

  I've got a couple of vSphere 5.0 hosts in a small lab environment here and I've noticed a strange behaviour. When on of the hosts gets rebooted, it is unresponsive to the network until I log into the ESX console, Press F2 to customize and select Restart management network. Once this is done, the networking works perfectly as expected. Each host has two NICs which are trunked together using Etherchannel to a Cisco 3750. The link is also a .1q VLAN trunk and the management network is configured on VLAN121 with the VM traffic configured on VLAN118. Why would the host be completely dead to the world until I physically kick it? Edit Sample switch config for trunk: interface Port-channel2 description Blade 1 EtherChannel Trunk switchport trunk encapsulation dot1q switchport mode trunk end ! ! interface GigabitEthernet4/0/1 description Bladecenter1 CPM 1A switchport trunk encapsulation dot1q switchport mode trunk speed 1000 duplex full channel-group 2 mode on end Vswitch teaming settings: Management port group settings:

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• Good SQL error handling in Strored Procedure

  - by developerit

  When writing SQL procedures, it is really important to handle errors cautiously. Having that in mind will probably save your efforts, time and money. I have been working with MS-SQL 2000 and MS-SQL 2005 (I have not got the opportunity to work with MS-SQL 2008 yet) for many years now and I want to share with you how I handle errors in T-SQL Stored Procedure. This code has been working for many years now without a hitch. N.B.: As antoher "best pratice", I suggest using only ONE level of TRY … CATCH and only ONE level of TRANSACTION encapsulation, as doing otherwise may not be 100% sure. BEGIN TRANSACTION; BEGIN TRY -- Code in transaction go here COMMIT TRANSACTION; END TRY BEGIN CATCH -- Rollback on error ROLLBACK TRANSACTION; -- Raise the error with the appropriate message and error severity DECLARE @ErrMsg nvarchar(4000), @ErrSeverity int; SELECT @ErrMsg = ERROR_MESSAGE(), @ErrSeverity = ERROR_SEVERITY(); RAISERROR(@ErrMsg, @ErrSeverity, 1); END CATCH; In conclusion, I will just mention that I have been using this code with .NET 2.0 and .NET 3.5 and it works like a charm. The .NET TDS parser throws back a SQLException which is ideal to work with.

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• When are Getters and Setters Justified

  - by Winston Ewert

  Getters and setters are often criticized as being not proper OO. On the other hand most OO code I've seen has extensive getters and setters. When are getters and setters justified? Do you try to avoid using them? Are they overused in general? If your favorite language has properties (mine does) then such things are also considered getters and setters for this question. They are same thing from an OO methodology perspective. They just have nicer syntax. Sources for Getter/Setter Criticism (some taken from comments to give them better visibility): http://www.javaworld.com/javaworld/jw-09-2003/jw-0905-toolbox.html http://typicalprogrammer.com/?p=23 http://c2.com/cgi/wiki?AccessorsAreEvil http://www.darronschall.com/weblog/2005/03/no-brain-getter-and-setters.cfm http://www.adam-bien.com/roller/abien/entry/encapsulation_violation_with_getters_and To state the criticism simply: Getters and Setters allow you to manipulate the internal state of objects from outside of the object. This violates encapsulation. Only the object itself should care about its internal state. And an example Procedural version of code. struct Fridge { int cheese; } void go_shopping(Fridge fridge) { fridge.cheese += 5; } Mutator version of code: class Fridge { int cheese; void set_cheese(int _cheese) { cheese = _cheese; } int get_cheese() { return cheese; } } void go_shopping(Fridge fridge) { fridge.set_cheese(fridge.get_cheese() + 5); } The getters and setters made the code much more complicated without affording proper encapsulation. Because the internal state is accessible to other objects we don't gain a whole lot by adding these getters and setters. The question has been previously discussed on Stack Overflow: http://stackoverflow.com/questions/565095/java-are-getters-and-setters-evil http://stackoverflow.com/questions/996179

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• Single Responsibility Principle - How Can I Avoid Code Fragmentation?

  - by Dean Chalk

  I'm working on a team where the team leader is a virulent advocate of SOLID development principles. However, he lacks a lot of experience in getting complex software out of the door. We have a situation where he has applied SRP to what was already quite a complex code base, which has now become very highly fragmented and difficult to understand and debug. We now have a problem not only with code fragmentation, but also encapsulation, as methods within a class that may have been private or protected have been judged to represent a 'reason to change' and have been extracted to public or internal classes and interfaces which is not in keeping with the encapsulation goals of the application. We have some class constructors which take over 20 interface parameters, so our IoC registration and resolution is becoming a monster in its own right. I want to know if there is any 'refactor away from SRP' approach we could use to help fix some of these issues. I have read that it doesn't violate SOLID if I create a number of empty courser-grained classes that 'wrap' a number of closely related classes to provide a single-point of access to the sum of their functionality (i.e. mimicking a less overly SRP'd class implementation). Apart from that, I cannot think of a solution which will allow us to pragmatically continue with our development efforts, while keeping everyone happy. Any suggestions ?

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• JavaScript Class Patterns Revisited: Endgame

  - by Liam McLennan

  I recently described some of the patterns used to simulate classes (types) in JavaScript. But I missed the best pattern of them all. I described a pattern I called constructor function with a prototype that looks like this: function Person(name, age) { this.name = name; this.age = age; } Person.prototype = { toString: function() { return this.name + " is " + this.age + " years old."; } }; var john = new Person("John Galt", 50); console.log(john.toString()); and I mentioned that the problem with this pattern is that it does not provide any encapsulation, that is, it does not allow private variables. Jan Van Ryswyck recently posted the solution, obvious in hindsight, of wrapping the constructor function in another function, thereby allowing private variables through closure. The above example becomes: var Person = (function() { // private variables go here var name,age; function constructor(n, a) { name = n; age = a; } constructor.prototype = { toString: function() { return name + " is " + age + " years old."; } }; return constructor; })(); var john = new Person("John Galt", 50); console.log(john.toString()); Now we have prototypal inheritance and encapsulation. The important thing to understand is that the constructor, and the toString function both have access to the name and age private variables because they are in an outer scope and they become part of the closure.

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• Philosophy behind the memento pattern

  - by TheSilverBullet

  I have been reading up on memento pattern from various sources of the internet. Differing information from different sources has left me in confusion regarding why this pattern is actually needed. The dofactory implementation says that the primary intention of this pattern is to restore the state of the system. Wiki says that the primary intention is to be able to restore the changes on the system. This gives a different impact - saying that it is possible for a system to have memento implementation with no need to restore. And that ability of restore is a feature of this. OODesign says that It is sometimes necessary to capture the internal state of an object at some point and have the ability to restore the object to that state later in time. Such a case is useful in case of error or failure. So, my question is why exactly do we use this one? Is it to save previous states - or to promote encapsulation between the Caretaker and the Memento? Why is this type of encapsulation so important? Edit: For those visiting, check out this Implementation!

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• Encapsulating code in F# (Part 2)

  - by MarkPearl

  In part one of this series I showed an example of encapsulation within a local definition. This is useful to know so that you are aware of the scope of value holders etc. but what I am more interested in is encapsulation with regards to generating useful F# code libraries in .Net, this is done by using Namespaces and Modules. Lets have a look at some C# code first… using System; namespace EncapsulationNS { public class EncapsulationCLS { public static void TestMethod() { Console.WriteLine("Hello"); } } } Pretty simple stuff… now the F# equivalent…. namespace EncapsulationNS module EncapsulationMDL = let TestFunction = System.Console.WriteLine("Hello") ()   Even easier… lets look at some specifics about F# namespaces… Namespaces are open. meaning you can have multiple source files and assemblies can contribute to the same namespace. So, Namespaces are a great way to group modules together, so the question needs to be asked, what role do modules play. For me, the F# module is in many ways similar to the vb6 days of modules. In vb6 modules were separate files and simply allowed us to group certain methods together. I find it easier to visualize F# modules this way than to compare them to the C# classes. However that being said one is not restricted to one module per file – there is flexibility to have multiple modules in one code file however with my limited F# experience I would still recommend using the file as the standard level of separating modules as it is very easy to then find your way around a solution. An important note about interop with F# and other .Net languages. I wrote a blog post a while back about a very basic F# to C# interop. If I were to reference an F# library in a C# project (for instance ‘TestFunction’), in C# it would show this method as a static method call, meaning I would not have to instantiate an instance of the module.

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• c# vocabulary

  - by foxjazz

  I have probably seen and used the word Encapsulation 4 times in my 20 years of programming.I now know what it is again, after an interview for a c# job. Even though I have used the public, private, and protected key words in classes for as long as c# was invented. I can sill remember coming across the string.IndexOf function and thinking, why didn't they call it IndexAt.Now with all the new items like Lambda and Rx, Linq, map and pmap etc, etc. I think the more choices there is to do 1 or 2 things 10 or 15 differing ways, the more programmers think to stay with what works and try and leverage the new stuff only when it really becomes beneficial.For many, the new stuff is harder to read, because programmers aren't use to seeing declarative notation.I mean I have probably used yield break, twice in my project where it may have been possible to use it many more times. Or the using statement ( not the declaration of namespace references) but inline using. I never really saw a big advantage to this, other than confusion. It is another form of local encapsulation (oh there 5 times used in my programming career) but who's counting?  THE COMPUTERS ARE COUNTING!In business logic most programming is about displaying lists, selecting items in a list, and sending those choices to some other system or database to keep track of those selections. What makes this difficult is how these items relate to one, each other, and two externally listed items.Well I probably need to go back to school and learn c# certification so I can say I am an expert in c#. Apparently using all aspects of c# (even unsafe code) in my programming life, doesn't make me certified, just certifiable.This is a good time to sign off:Fox-jazzy

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• What is the correct Qt idiom for exposing signals/slots of contained widgets?

  - by Tyler McHenry

  Suppose I have a MyWidget which contains a MySubWidget, e.g. a custom widget that contains a text field or something. I want other classes to be able to connect to signals and slots exposed by the contained MySubWidget instance. Is the conventional way to do this: Expose a pointer to the MySubWidget instance through a subWidget() method in MyWidget Duplicate the signals and slots of MySubWidget in the MyWidget class and write "forwarding" code Something else? Choice 1 seems like the least code, but it also sort of breaks encapsulation, since now other classes know what the contained widgets of MyWidget are and might become dependent on their functionality. Choice 2 seems like it keeps encapsulation, but it's a lot of seemingly redundant and potentially convoluted code that kind of messes up the elegance of the whole signals and slots system. What is normally done in this situation?

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