The Whiteboard

overexchange

10:23 AM

thank you

Ixrec

hi

overexchange

hai

Ixrec

so you had questions about Javascript objects?

overexchange

If I ignore proto inher, how would you create obejcts in javascript?

yes

Ixrec

the simplest way is using object literals, which I believe are basically the same as Python dictionary literals

var x = {
d_number: 3,
d_foo: function() { return this.d_number; }
};

and this is essentially the same thing as the first code snippet in your question

overexchange

10:27 AM

so you created an object with its state(value 3) and behaviour and x point to that object

correct?

Ixrec

yep

overexchange

ok

Ixrec

I believe most dynamic scriping languages allow this to some degree

JS also has some syntactic sugar; instead of a "class" keyword when defining the class it has a "new" keyword when constructing objects

overexchange

If you are writing similar code for account, then I would say creating abstraction account using objects, corrct?

Ixrec

typically you'd use it like this:
var Foo = function(initialValue) {
this.d_number = initialValue;
this.d_foo = function() { return this.d_number; }
}
var f = new Foo(3);
var g = new Foo(5);

I'm not sure I know exactly what you're referring to there but something like that yes

a more typical phrase might be using objects to encapsulate the account's data

overexchange

10:32 AM

when I say abstraction, it is the method to create barrier between representation and usage

Ixrec

incidentally, prototypal inheritance simply turns that example into this:
var Foo = function(initialValue) {
this.d_number = initialValue;
}
Foo.prototype.d_foo = function() { return this.d_number; }

var f = new Foo(3);
var g = new Foo(5);

overexchange

in my first code represe is dispatch = {'balance': 0, 'withdraw': withdraw, 'deposit': deposit}

Ixrec

sure, that specific type of abstraction I'd normally use "encapsulation" for, but all these terms are vague buzzwords so whatever works for you

not sure why I was using the d_ prefix on a public method in those examples, but too late now

overexchange

so how do you introduce inheritance with such first approach?

Did you get my question?

Ixrec

the short answer is that prototypes are transitive, iirc you can do something like Bar.prototype.prototype = Foo.prototype and then doing Bar.d_foo will eventually find d_foo on Foo's prototype

I forget exactly how this works because almost no one "hooks up" prototypes manually like that, even in plain Javascript we rely on Object.create() to do that part

developer.mozilla.org/en-US/docs/Web/JavaScript/… coves this in a lot of detail

overexchange

10:42 AM

python syntax would help me, because we do not have prototype concept in python

Is prototype concept introduce to provide ineritance in javascript?

Ixrec

yeah, prototypal inheritance is unusual, I'm pretty sure Python does not have it

Javascript is probably the only "mainstream" language using it

it has a lot of strange and interesting consequences that can be useful or dangerous

overexchange

I see that you introduce the attribute(d_number) without prototype syntax but method Foo.prototype.d_foo = funtionc(){}. why is that?

Ixrec

"without proto"?

ah

the difference is that there is only one prototype, even when multiple objects share that prototype

if I did Foo.prototype.number = 3;, then there would only be one "number" shared among all instances of Foo, which is not what we want

whereas for a public method, we typically want there to be only one implementation shared by all instances of Foo, rather than each Foo object carrying around its own separate implementation

overexchange

ok

some thing like static member in java class

Ixrec

partly for performance reasons (all those extra function literals waste time and memory) and partly because those are the desired semantics

the static analogy unfortunately does not work; static methods are called without any object instance to be called on

a method on the prototype chain still is being called on a specific object

overexchange

10:48 AM

ya

Ixrec

you can see why people might find this weird and confusing

I have to go now, but one last thing I wanted to mention

overexchange

Bar.prototype.prototype = Foo.prototype looks horrible syntax to learn as a beginner

ok

Ixrec

you can also add things to the prototypes of built-in object types in javascript, eg
Array.prototype.getFirst = function() { return this[0]; }

whether this is useful or extremely dangerous is controversial

yeah, use Object.create()

g2g now

overexchange

ok thank you

Jimmy Hoffa

1:00 PM

ugh do not use inheritance in JavaScript..

Next time you get the hankering to do so, stick yourself with a pin until the sensation passes

Ixrec

it's pretty rare for me to use inheritance in any language; in Javascript I think I've only ever done it when someone else's API forced me to

being able to pass function literals around is just so much more flexible and expressive (at least with what I'm doing)

user55340

3:07 PM

'Optimal' US road trip

user55340

3:30 PM

rsi could use delete votes... everything is closed.

Duga

5:07 PM

I'm voting to close this question as off-topic because it is about legal issues, and Stack Overflow is not in the position to give out legal advice. It might be better on Programmers Stack Exchange instead. — Kevin Brown 26 secs ago

Duga

5:22 PM

We do accept some licensing questions on Programmers.SE, but most legal questions are off-topic, because we aren't equipped to give legal advice either. This one might be okay, though it seems to have gotten a good answer here already. — Ixrec 1 min ago

durron597

7:28 PM

38

Q: Would you purchase hardware with your own money to use at work to do your job better?

At work, I was given a reasonably-spec'ed machine (dual quad 2GHz, 4GB RAM, 160GB 7200RPM drive, Win7), but it was lacking in a few places (HDD / RAM). The IT staff was OK with me replacing hardware with my own, so now I'm sporting an SSD and an extra 8GB of RAM (so I can run multiple Visual Stu...

^^ the last job-satisfaction with no CVs on it.

Ixrec

no I would not

and unfortunately I already used all my CVs on work-environment today

durron597

@Ixrec I had 7 left after my 20 reviews and I used them on 7/8 job-satisfaction

I want to kill the small tags quickly so it makes my life easier to make the status post ;)

Ixrec

for some silly reason I expected work-environment to be one of the smaller ones

tomorrow I'll check a few more before picking a target

durron597

Well the number is there in the status post

Ixrec

I started from the meta thread

durron597

7:32 PM

Yeah I've been using the chatroom to keep the numbers. I don't think Thomas wants me to put numbers in the meta thread because he's edited them out in the past.

probably because they never stay accurate for more than an hour.

plus, these links have "closed:no locked:no", which they don't have in the meta thread.

Ixrec

yeah, I know all these things, I don't know why I didn't use the pinned chat links today

probably juggling this with too many other tasks

durron597

@Ixrec I hear ya

gnat

8:06 PM

can we please point some... X-rays towards this "question"

Ixrec

I have done what little I can (downvote)

Jimmy Hoffa

8:38 PM

0

Q: How can I learn WPF Adorner

Just like the topic, I would like to learn how to use Adorners in WPF, but all the online resources I see only try to treat a particular problem and do not actually teach you to learn, I have taken a look at the MSDN site, and I do not really like it

c# .net wpf

user55340

9:30 PM

Heh...

user55340

Question from '10 was reposted here (back in '10) and never closed on SO...

user55340

1

Q: Required skills for a senior level ActionScript/Flex developer

I'm looking to take my Actionscript knowledge to the next level and I've been having trouble finding what it takes to become a senior level AS developer. From my searching this has what I've come up with so far: Component Creation Memory Usage Debugging/Profiling AS specific usage of OOP Corre...

job-definition actionscript senior-developer

user55340

1

Q: Required skills for a senior level ActionScript/Flex developer

I'm looking to take my Actionscript knowledge to the next level and I've been having trouble finding what it takes to become a senior level AS developer. From my searching this has what I've come up with so far: Component Creation Memory Usage Debugging/Profiling AS specific usage of OOP Corr...

flex actionscript-3 actionscript

durron597

9:44 PM

ChrisF edited the STCI tag out of this one, but didn't historical lock it and left it pending:

109

Q: You're hired to fix a small bug for a security-intensive site. Looking at the code, it's filled with security holes. What do you do?

I've been hired by someone to do some small work on a site. It's a site for a large company. It contains very sensitive data, so security is very important. Upon analyzing the code, I've noticed it's filled with security holes - read, lots of PHP files throwing user get/post input directly into m...

php security sql-injection

André

gawd, Android development is so clunky

Duga

@AshutoshNarang you could accept the answer that you think worked better for you, it seems that the one you accepted is the one that worked, but also remember that this site is visited by programmers seeking for solutions and they often use answers from previous questions. — iharob 6 secs ago

Anonymous

10:00 PM

@André battling with the slow simulator?

Anonymous

also, good evening everyobdy

Ixrec

evening

Anonymous

does anybody write and understand perl?

Anonymous

I'd ask around in SO, but most of those folks only do JS/any other language that became popular after 2005

Ixrec

I don't, but if no one in here does you could try the PPCG guys chat.stackexchange.com/rooms/240/the-nineteenth-byte

Anonymous

10:09 PM

hmm codegolf... how could I forget that last bastion of perl programmers haha... thanks!

Ixrec

it's literally the only place I've ever seen people write actual Perl code =)

Anonymous

@Ixrec haha well... code golfing doesn't exactly encourage people to write modern and correct perl

Telastyn

I used perl like 15 years ago

Anonymous

@Telastyn have you ever had to deal with one of the most typical problems? ie: parse this html table

André

10:29 PM

@PatoSáinz, battling a non compliant JRE, so many edge cases

Duga

It would probably be better fit at Programmers SE — michaelpri 35 secs ago

André

Just use a regex @PatoSáinz

Telastyn

@PatoSáinz - no, did mostly command line automation stuff. I expect cpan has a hojillion html parsers.

Anonymous

@André oh god you have to see the table I'm trying to parse

Anonymous

it's a bloody mess

Anonymous

10:32 PM

of course I've done my homework with HTML::TableExtract, other modules and web services

Anonymous

hell I even searched if IBM Watson had a table churning service

Anonymous

paste.c99.nl/ocnAU.html

Anonymous

there's an example table

Anonymous

it's a mess

Anonymous

what I want to produce out of that table is, for example, a nice array with all the grades (under the "NotaX" headers) of a given subject (say, "Matemáticas")

Anonymous

10:34 PM

@André cue the typical StackOverflow: "don't use regexes for HTML" advice

André

It was a joke :-)

Anonymous

@André hahaha I see

André

I don't want cthulhu waking up

Telastyn

doesn't seem that substandard

Anonymous

@Telastyn so how would you tackle it? I don't know where to start

Telastyn

10:38 PM

grab some lib to parse the html into bits, write a little bit of code to extract the data I want from the tree, liberally hardcoding "there will be one table, and I expect it to be in this shape" logic

Anonymous

@Telastyn can you please elaborate more into your idea? It's been over a year since I last wrote code and I'm kind of starting slow

Telastyn

so I expect to be able to find a library for most any language that will give you a tree from the parsed html

html -> body -> table -> ...

Anonymous

yes, there's a library like that

Telastyn

I would then write some code akin to: "find first table in body (or explode horribly); Get rows 1-max (assuming first row is header); For each row, find first child of each cell that has content (as opposed to tags) and add to list"

very literal

very fragile

run, compare output to expected and tweak as necessary.

import data, then discard code.

Anonymous

luckily, all the tables I have to parse are in this exact same awful form

Anonymous

10:43 PM

so one literal fragile script is all it takes

Anonymous

if only I had access to the database that spews out that data

Anonymous

there's not even an API so I mean... actual DB access

Telastyn

shrug if it were nice, it'd be done already.

Anonymous

@Telastyn even the tables some of the obscure USGov sites show you aren't as horrible

Telastyn

shrug

Robert Harvey

11:10 PM

This question...

0

Q: Are the Repository Pattern and Active Record pattern compatible?

Currently I am developing a webapp where I have defined models implementing the Active Record pattern. Each model also is defined by an interface that specifies the Entity properties and makes it easy to inject it into other classes, specially useful for unit testing. I am looking forward to impl...

design-patterns patterns-and-practices architectural-patterns entity activerecord

He's talking about injecting a data access mechanism into a repository, so that the repository can retrieve data from the database. But if you want to do that, you would have to write your data access mechanisms to conform to a particular interface so that you could inject the desired one into the repository.

The repository is the place where you define your API for the consumer. So, rather than have some sort of IRetrieve interface that the repository accepts into the constructor, wouldn't it make more sense to have separate IRepository implementations, each of which uses a different database access mechanism?

In other words, isn't an API that conforms to some IDatabaseRetrievalMechanism interface essentially the same thing as a Repository?

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