WEBVTT

1
00:00:01.820 --> 00:00:03.980
alright so the changes we made at the

2
00:00:03.980 --> 00:00:06.290
end of the last video enable us to send
alright so the changes we made at the

3
00:00:06.290 --> 00:00:07.910
the output to a file if you want to
end of the last video enable us to send

4
00:00:07.910 --> 00:00:10.009
using the technique we saw back in
the output to a file if you want to

5
00:00:10.009 --> 00:00:12.080
Section 10 when we were writing to
using the technique we saw back in

6
00:00:12.080 --> 00:00:13.190
files
Section 10 when we were writing to

7
00:00:13.190 --> 00:00:14.749
alright so let's make sure that it still
files

8
00:00:14.749 --> 00:00:16.369
works and that it looks the same as it did
alright so let's make sure that it still

9
00:00:16.369 --> 00:00:18.679
before so now we can send the output to
works and that it looks the same as it did

10
00:00:18.679 --> 00:00:20.689
a file and see how it displays in a
before so now we can send the output to

11
00:00:20.689 --> 00:00:22.730
browser so lets actually do that so what
a file and see how it displays in a

12
00:00:22.730 --> 00:00:25.400
we're going to do is after the
browser so lets actually do that so what

13
00:00:25.400 --> 00:00:28.609
tag the paragraph tag we're going to do
we're going to do is after the

14
00:00:28.609 --> 00:00:35.690
....
tag the paragraph tag we're going to do

15
00:00:35.690 --> 00:00:41.690
....
....

16
00:00:41.690 --> 00:00:44.390
...
....

17
00:00:44.390 --> 00:00:47.600
....
...

18
00:00:47.600 --> 00:00:51.199
...
....

19
00:00:51.199 --> 00:00:57.199
....
...

20
00:00:57.199 --> 00:00:59.149
and we'll just open the project pane so
....

21
00:00:59.149 --> 00:01:00.170
we can see that the file gets
and we'll just open the project pane so

22
00:01:00.170 --> 00:01:02.359
created for us now if you are using
we can see that the file gets

23
00:01:02.359 --> 00:01:03.980
linux or mac do make sure you add the
created for us now if you are using

24
00:01:03.980 --> 00:01:06.740
dot HTML file extension even if you
linux or mac do make sure you add the

25
00:01:06.740 --> 00:01:07.909
wouldn't normally do that and I'll
dot HTML file extension even if you

26
00:01:07.909 --> 00:01:09.530
explain why in a minute
wouldn't normally do that and I'll

27
00:01:09.530 --> 00:01:11.119
now we can send the output of the
explain why in a minute

28
00:01:11.119 --> 00:01:13.520
display method to a file by adding test
now we can send the output of the

29
00:01:13.520 --> 00:01:16.460
_doc as the named perimeter in the
display method to a file by adding test

30
00:01:16.460 --> 00:01:18.710
call to display and you saw me do that on line
_doc as the named perimeter in the

31
00:01:18.710 --> 00:01:23.900
69 so let's just run this you can
call to display and you saw me do that on line

32
00:01:23.900 --> 00:01:25.850
see that was very quick and then the
69 so let's just run this you can

33
00:01:25.850 --> 00:01:29.450
file test.HTML appeared now intelliJ
see that was very quick and then the

34
00:01:29.450 --> 00:01:31.759
understands about HTML so i can
file test.HTML appeared now intelliJ

35
00:01:31.759 --> 00:01:33.170
right-click the test file in the project
understands about HTML so i can

36
00:01:33.170 --> 00:01:37.460
pane the context menu their is an open in
right-click the test file in the project

37
00:01:37.460 --> 00:01:40.640
browser down here and that's why I
pane the context menu their is an open in

38
00:01:40.640 --> 00:01:42.020
mentioned that you should include the
browser down here and that's why I

39
00:01:42.020 --> 00:01:44.540
file extension linux and osx don't
mentioned that you should include the

40
00:01:44.540 --> 00:01:46.340
rely on the file extension to decide
file extension linux and osx don't

41
00:01:46.340 --> 00:01:47.869
what to do with the file but
rely on the file extension to decide

42
00:01:47.869 --> 00:01:49.399
intelliJ has adopted the windows
what to do with the file but

43
00:01:49.399 --> 00:01:51.229
approach and does use the file extension
intelliJ has adopted the windows

44
00:01:51.229 --> 00:01:54.200
so if the file doesn't have a dot HTM or
approach and does use the file extension

45
00:01:54.200 --> 00:01:56.960
dot HTML extension then you won't get
so if the file doesn't have a dot HTM or

46
00:01:56.960 --> 00:01:58.939
the option to open in your browser
dot HTML extension then you won't get

47
00:01:58.939 --> 00:02:01.189
alright so in my case though i'm going
the option to open in your browser

48
00:02:01.189 --> 00:02:02.509
to choose chrome which is the one that I
alright so in my case though i'm going

49
00:02:02.509 --> 00:02:03.979
normally do when i'm recording videos
to choose chrome which is the one that I

50
00:02:03.979 --> 00:02:06.229
you can choose the default
normally do when i'm recording videos

51
00:02:06.229 --> 00:02:09.080
browser and we can see that it's
you can choose the default

52
00:02:09.080 --> 00:02:10.580
actually popped up now and it's working
browser and we can see that it's

53
00:02:10.580 --> 00:02:11.690
quite nicely
actually popped up now and it's working

54
00:02:11.690 --> 00:02:14.600
alright so that's composition now we've
quite nicely

55
00:02:14.600 --> 00:02:15.420
used both
alright so that's composition now we've

56
00:02:15.420 --> 00:02:17.700
composition and inheritance in this program
used both

57
00:02:17.700 --> 00:02:19.680
so it's a good example of the
composition and inheritance in this program

58
00:02:19.680 --> 00:02:21.660
differences between them and when you
so it's a good example of the

59
00:02:21.660 --> 00:02:24.510
use each one so getting back to our code
differences between them and when you

60
00:02:24.510 --> 00:02:30.450
now our basic classes all inherit from
use each one so getting back to our code

61
00:02:30.450 --> 00:02:32.280
tagged and when we talk about head for
now our basic classes all inherit from

62
00:02:32.280 --> 00:02:35.459
example would say that head is a tag
tagged and when we talk about head for

63
00:02:35.459 --> 00:02:38.280
similarly body is a tag and so is
example would say that head is a tag

64
00:02:38.280 --> 00:02:40.620
doctype although doc type are slightly
similarly body is a tag and so is

65
00:02:40.620 --> 00:02:42.510
different kind of tag it doesn't have a
doctype although doc type are slightly

66
00:02:42.510 --> 00:02:44.790
corresponding end tag so whenever you
different kind of tag it doesn't have a

67
00:02:44.790 --> 00:02:46.230
have a relationship that can be
corresponding end tag so whenever you

68
00:02:46.230 --> 00:02:48.269
described using is a that's an
have a relationship that can be

69
00:02:48.269 --> 00:02:49.470
indication that you should consider
described using is a that's an

70
00:02:49.470 --> 00:02:52.260
using inheritance to model the objects
indication that you should consider

71
00:02:52.260 --> 00:02:54.239
composition is used when the
using inheritance to model the objects

72
00:02:54.239 --> 00:02:57.060
relationship is described as a has a a
composition is used when the

73
00:02:57.060 --> 00:03:00.299
document has a doctype and has a body so
relationship is described as a has a a

74
00:03:00.299 --> 00:03:02.220
composition is more appropriate to model
document has a doctype and has a body so

75
00:03:02.220 --> 00:03:03.330
the document
composition is more appropriate to model

76
00:03:03.330 --> 00:03:04.799
ok there's another example of
the document

77
00:03:04.799 --> 00:03:06.630
composition being used in our body class
ok there's another example of

78
00:03:06.630 --> 00:03:09.390
so let's have a look at that HTML
composition being used in our body class

79
00:03:09.390 --> 00:03:10.980
doc object has to contain a
so let's have a look at that HTML

80
00:03:10.980 --> 00:03:14.459
doctype a head tag and a body tag so it's
doc object has to contain a

81
00:03:14.459 --> 00:03:16.860
effectively not an HTML document without
doctype a head tag and a body tag so it's

82
00:03:16.860 --> 00:03:17.580
them
effectively not an HTML document without

83
00:03:17.580 --> 00:03:19.709
so these three components are created
them

84
00:03:19.709 --> 00:03:21.480
when each instance of the class is
so these three components are created

85
00:03:21.480 --> 00:03:24.959
created in the init method you can see
when each instance of the class is

86
00:03:24.959 --> 00:03:26.280
its doing that down here starting on line
created in the init method you can see

87
00:03:26.280 --> 00:03:29.579
47 now body object has any number of
its doing that down here starting on line

88
00:03:29.579 --> 00:03:32.609
tags and maybe empty that would make for
47 now body object has any number of

89
00:03:32.609 --> 00:03:34.680
a very interesting document but it would
tags and maybe empty that would make for

90
00:03:34.680 --> 00:03:37.709
actually conform to the specification so
a very interesting document but it would

91
00:03:37.709 --> 00:03:39.570
we don't create any objects when body
actually conform to the specification so

92
00:03:39.570 --> 00:03:41.910
instances are created instead we just
we don't create any objects when body

93
00:03:41.910 --> 00:03:44.220
create an empty list ready to contain
instances are created instead we just

94
00:03:44.220 --> 00:03:47.250
the tags when they're added you can see
create an empty list ready to contain

95
00:03:47.250 --> 00:03:49.620
that code for that here on line 32 now
the tags when they're added you can see

96
00:03:49.620 --> 00:03:51.600
when a tag is added to the body by
that code for that here on line 32 now

97
00:03:51.600 --> 00:03:53.400
calling the body classes add_
when a tag is added to the body by

98
00:03:53.400 --> 00:03:56.489
tag method a new tag objects created then
calling the body classes add_

99
00:03:56.489 --> 00:03:59.160
appended to the list now this is also
tag method a new tag objects created then

100
00:03:59.160 --> 00:04:01.980
composition but now the body class has
appended to the list now this is also

101
00:04:01.980 --> 00:04:04.769
its own attributes isn't just composed
composition but now the body class has

102
00:04:04.769 --> 00:04:06.510
of its composite classes
its own attributes isn't just composed

103
00:04:06.510 --> 00:04:08.220
it has an underscore body _
of its composite classes

104
00:04:08.220 --> 00:04:10.829
contents data attribute and a method
it has an underscore body _

105
00:04:10.829 --> 00:04:12.690
called add underscore tag
contents data attribute and a method

106
00:04:12.690 --> 00:04:14.459
alright so at this point anything else
called add underscore tag

107
00:04:14.459 --> 00:04:16.620
to say about this wil all be repetition
alright so at this point anything else

108
00:04:16.620 --> 00:04:19.019
so it's time for a challenge to
to say about this wil all be repetition

109
00:04:19.019 --> 00:04:21.090
consolidate what we covered to give you
so it's time for a challenge to

110
00:04:21.090 --> 00:04:23.669
a bit of a chance to apply it at the
consolidate what we covered to give you

111
00:04:23.669 --> 00:04:26.039
moment ahead class doesn't create a
a bit of a chance to apply it at the

112
00:04:26.039 --> 00:04:28.350
document header with anything in it
moment ahead class doesn't create a

113
00:04:28.350 --> 00:04:30.120
so your challenge is to modify the
document header with anything in it

114
00:04:30.120 --> 00:04:32.670
program so that the head class can
so your challenge is to modify the

115
00:04:32.670 --> 00:04:35.790
include a title tag and your HTML should
program so that the head class can

116
00:04:35.790 --> 00:04:37.050
look something like this
include a title tag and your HTML should

117
00:04:37.050 --> 00:04:38.760
although there's no need to include
look something like this

118
00:04:38.760 --> 00:04:40.680
line-breaks indenting I've just done
although there's no need to include

119
00:04:40.680 --> 00:04:42.840
that to make it easy to read but the
line-breaks indenting I've just done

120
00:04:42.840 --> 00:04:45.030
text for the title will be passed to the
that to make it easy to read but the

121
00:04:45.030 --> 00:04:47.580
html dot classes init method where
text for the title will be passed to the

122
00:04:47.580 --> 00:04:49.860
the documents created alright so that's
html dot classes init method where

123
00:04:49.860 --> 00:04:51.960
the challenge see how you go with that
the documents created alright so that's

124
00:04:51.960 --> 00:04:53.760
pause the video and I'll see you when
the challenge see how you go with that

125
00:04:53.760 --> 00:04:58.230
you get back ok so the basic approach
pause the video and I'll see you when

126
00:04:58.230 --> 00:05:00.000
this challenge will probably be the same
you get back ok so the basic approach

127
00:05:00.000 --> 00:05:02.370
for all solutions but you may well have
this challenge will probably be the same

128
00:05:02.370 --> 00:05:03.960
a different implementation to my
for all solutions but you may well have

129
00:05:03.960 --> 00:05:06.450
solution as always that's fine
a different implementation to my

130
00:05:06.450 --> 00:05:09.330
the real test is does it work if you get
solution as always that's fine

131
00:05:09.330 --> 00:05:11.010
the correct HTML produced then
the real test is does it work if you get

132
00:05:11.010 --> 00:05:12.180
congratulations
the correct HTML produced then

133
00:05:12.180 --> 00:05:15.180
alright so if you read through the basic
congratulations

134
00:05:15.180 --> 00:05:18.210
HTML structure that we looked in the
alright so if you read through the basic

135
00:05:18.210 --> 00:05:20.100
browser earlier you may have noticed
HTML structure that we looked in the

136
00:05:20.100 --> 00:05:21.360
that the head can contain a few
browser earlier you may have noticed

137
00:05:21.360 --> 00:05:23.520
different tags so you may have made the
that the head can contain a few

138
00:05:23.520 --> 00:05:27.060
head class behave like a body class with
different tags so you may have made the

139
00:05:27.060 --> 00:05:29.130
an add_tag method to add new content
head class behave like a body class with

140
00:05:29.130 --> 00:05:31.710
to the head element that's fine it's
an add_tag method to add new content

141
00:05:31.710 --> 00:05:33.720
probably the way you do things so that
to the head element that's fine it's

142
00:05:33.720 --> 00:05:36.450
the program correctly reflects the HTML
probably the way you do things so that

143
00:05:36.450 --> 00:05:39.090
specification the challenge we asked for
the program correctly reflects the HTML

144
00:05:39.090 --> 00:05:41.580
a title so for my solution i'm just
specification the challenge we asked for

145
00:05:41.580 --> 00:05:43.620
going to add a title and nothing more
a title so for my solution i'm just

146
00:05:43.620 --> 00:05:45.240
so the first step is to modify the head
going to add a title and nothing more

147
00:05:45.240 --> 00:05:49.560
class and we need to modify the init
so the first step is to modify the head

148
00:05:49.560 --> 00:05:51.900
method to take another argument which
class and we need to modify the init

149
00:05:51.900 --> 00:05:53.910
effectively will be the title going to
method to take another argument which

150
00:05:53.910 --> 00:05:57.210
come up here we're going to put....
effectively will be the title going to

151
00:05:57.210 --> 00:06:01.860
....
come up here we're going to put....

152
00:06:01.860 --> 00:06:05.520
...
....

153
00:06:05.520 --> 00:06:09.630
...
...

154
00:06:09.630 --> 00:06:12.840
....
...

155
00:06:12.840 --> 00:06:14.100
...
....

156
00:06:14.100 --> 00:06:16.440
...
...

157
00:06:16.440 --> 00:06:18.540
....
...

158
00:06:18.540 --> 00:06:23.700
...
....

159
00:06:23.700 --> 00:06:27.540
....so this creates a new
...

160
00:06:27.540 --> 00:06:30.750
tag with the name title and the contents
....so this creates a new

161
00:06:30.750 --> 00:06:32.760
being the text that was passed in to the
tag with the name title and the contents

162
00:06:32.760 --> 00:06:35.430
init method now the head contents are
being the text that was passed in to the

163
00:06:35.430 --> 00:06:37.560
then set to this the string
init method now the head contents are

164
00:06:37.560 --> 00:06:39.810
representation of this new tag now we
then set to this the string

165
00:06:39.810 --> 00:06:41.740
can improve that slightly
representation of this new tag now we

166
00:06:41.740 --> 00:06:43.539
if the title doesn't contain any text
can improve that slightly

167
00:06:43.539 --> 00:06:45.130
then we really don't want an empty tag
if the title doesn't contain any text

168
00:06:45.130 --> 00:06:47.949
inside the head so we can give the title
then we really don't want an empty tag

169
00:06:47.949 --> 00:06:50.199
parameter a default value than test
inside the head so we can give the title

170
00:06:50.199 --> 00:06:52.690
this before creating the tag
parameter a default value than test

171
00:06:52.690 --> 00:06:54.340
let's go ahead and do that i'm going to
this before creating the tag

172
00:06:54.340 --> 00:06:58.810
put....
let's go ahead and do that i'm going to

173
00:06:58.810 --> 00:07:00.099
...
put....

174
00:07:00.099 --> 00:07:10.720
...
...

175
00:07:10.720 --> 00:07:12.160
alright next thing we need to do is
...

176
00:07:12.160 --> 00:07:15.940
modify the HTML dot class now first it
alright next thing we need to do is

177
00:07:15.940 --> 00:07:18.069
needs a parameter to the init method to
modify the HTML dot class now first it

178
00:07:18.069 --> 00:07:20.919
accept the title and we'll use a named
needs a parameter to the init method to

179
00:07:20.919 --> 00:07:22.479
parameter with the default value here as
accept the title and we'll use a named

180
00:07:22.479 --> 00:07:25.150
well that way a document can be created
parameter with the default value here as

181
00:07:25.150 --> 00:07:28.630
without providing a title so come
well that way a document can be created

182
00:07:28.630 --> 00:07:33.550
down to the html doc the init Method...
without providing a title so come

183
00:07:33.550 --> 00:07:35.860
...
down to the html doc the init Method...

184
00:07:35.860 --> 00:07:41.169
...
...

185
00:07:41.169 --> 00:07:45.159
...now the html .
...

186
00:07:45.159 --> 00:07:46.780
class doesn't have to do anything with
...now the html .

187
00:07:46.780 --> 00:07:48.969
the title it's just passing it on to the
class doesn't have to do anything with

188
00:07:48.969 --> 00:07:50.979
head class when it creates a new head
the title it's just passing it on to the

189
00:07:50.979 --> 00:07:53.080
object and that should be all we need to
head class when it creates a new head

190
00:07:53.080 --> 00:07:55.630
do I'm going to start by making sure we haven't
object and that should be all we need to

191
00:07:55.630 --> 00:07:57.250
broken anything so i'm going to run the
do I'm going to start by making sure we haven't

192
00:07:57.250 --> 00:08:01.509
program if we don't got any errors that is a
broken anything so i'm going to run the

193
00:08:01.509 --> 00:08:03.940
good sign and what i can do is open the
program if we don't got any errors that is a

194
00:08:03.940 --> 00:08:05.949
project pane I can also double-click
good sign and what i can do is open the

195
00:08:05.949 --> 00:08:08.349
that if i wanted to open the HTML file
project pane I can also double-click

196
00:08:08.349 --> 00:08:10.030
in the default browser but I'm going to
that if i wanted to open the HTML file

197
00:08:10.030 --> 00:08:12.340
right click it open a browser and choose
in the default browser but I'm going to

198
00:08:12.340 --> 00:08:16.270
chrome again that's it opening up now
right click it open a browser and choose

199
00:08:16.270 --> 00:08:18.940
in a new tab if we have a look at the
chrome again that's it opening up now

200
00:08:18.940 --> 00:08:22.750
HTML so far so good we haven't past a title
in a new tab if we have a look at the

201
00:08:22.750 --> 00:08:24.550
in so we haven't got a title and the
HTML so far so good we haven't past a title

202
00:08:24.550 --> 00:08:26.319
head tags up there on line three
in so we haven't got a title and the

203
00:08:26.319 --> 00:08:29.199
so that's good that's working so let's
head tags up there on line three

204
00:08:29.199 --> 00:08:31.090
see now if it works when we do passing a
so that's good that's working so let's

205
00:08:31.090 --> 00:08:32.919
title and i'll provide that when we
see now if it works when we do passing a

206
00:08:32.919 --> 00:08:36.159
create the HTML doc instance go back
title and i'll provide that when we

207
00:08:36.159 --> 00:08:37.060
to the code again
create the HTML doc instance go back

208
00:08:37.060 --> 00:08:40.839
so where we need to change this is on line
to the code again

209
00:08:40.839 --> 00:08:44.500
67 let's just make that....
so where we need to change this is on line

210
00:08:44.500 --> 00:08:48.579
....all right we'll run
67 let's just make that....

211
00:08:48.579 --> 00:08:53.709
again in a browser or open in browser and
....all right we'll run

212
00:08:53.709 --> 00:08:55.089
look at the source
again in a browser or open in browser and

213
00:08:55.089 --> 00:08:58.269
okay for some reason we haven't got a
look at the source

214
00:08:58.269 --> 00:08:59.439
a title lets just go back and check our
okay for some reason we haven't got a

215
00:08:59.439 --> 00:09:04.449
code ok looking at the code
a title lets just go back and check our

216
00:09:04.449 --> 00:09:06.069
definitely got the title in there and we go
code ok looking at the code

217
00:09:06.069 --> 00:09:08.620
back down I'll go back up i should say
definitely got the title in there and we go

218
00:09:08.620 --> 00:09:09.490
to the head
back down I'll go back up i should say

219
00:09:09.490 --> 00:09:12.220
we've definitely got the title
to the head

220
00:09:12.220 --> 00:09:15.069
arguments showing init method and we're
we've definitely got the title

221
00:09:15.069 --> 00:09:18.129
definitely creating a tag and that should all
arguments showing init method and we're

222
00:09:18.129 --> 00:09:19.839
be ok as far as I'm concerns just try
definitely creating a tag and that should all

223
00:09:19.839 --> 00:09:24.370
running it again and go back to browser
be ok as far as I'm concerns just try

224
00:09:24.370 --> 00:09:25.930
what we need to do is need to open it
running it again and go back to browser

225
00:09:25.930 --> 00:09:31.809
again open browser Chrome again let's
what we need to do is need to open it

226
00:09:31.809 --> 00:09:34.720
just look at the page source and it is
again open browser Chrome again let's

227
00:09:34.720 --> 00:09:36.579
....
just look at the page source and it is

228
00:09:36.579 --> 00:09:40.089
...
....

229
00:09:40.089 --> 00:09:42.670
...
...

230
00:09:42.670 --> 00:09:47.019
...ok so false alarm
...

231
00:09:47.019 --> 00:09:49.059
that was all working correctly and with
...ok so false alarm

232
00:09:49.059 --> 00:09:51.550
now got the test html containing a
that was all working correctly and with

233
00:09:51.550 --> 00:09:54.699
title tag inside the head and by the way
now got the test html containing a

234
00:09:54.699 --> 00:09:55.839
the other way we could have checked for
title tag inside the head and by the way

235
00:09:55.839 --> 00:09:58.240
that is if we just go back and
the other way we could have checked for

236
00:09:58.240 --> 00:10:02.230
closed down these view sources depending on
that is if we just go back and

237
00:10:02.230 --> 00:10:04.240
the browser you can actually see the
closed down these view sources depending on

238
00:10:04.240 --> 00:10:06.939
title in the browser bar but I can't the way
the browser you can actually see the

239
00:10:06.939 --> 00:10:08.259
chrome is configured on my
title in the browser bar but I can't the way

240
00:10:08.259 --> 00:10:10.029
computer right now that would be a
chrome is configured on my

241
00:10:10.029 --> 00:10:12.100
second way of doing it anyway because in
computer right now that would be a

242
00:10:12.100 --> 00:10:13.720
my case I'm still just seeing the URL of
second way of doing it anyway because in

243
00:10:13.720 --> 00:10:18.279
the document but depending on how your
my case I'm still just seeing the URL of

244
00:10:18.279 --> 00:10:20.379
browser is configured you probably see
the document but depending on how your

245
00:10:20.379 --> 00:10:22.179
the title in the browser's address bar
browser is configured you probably see

246
00:10:22.179 --> 00:10:22.959
anyway
the title in the browser's address bar

247
00:10:22.959 --> 00:10:25.179
alright so that's it that's composition
anyway

248
00:10:25.179 --> 00:10:27.339
in action in the next video we're going
alright so that's it that's composition

249
00:10:27.339 --> 00:10:28.389
to look at something that's often
in action in the next video we're going

250
00:10:28.389 --> 00:10:30.100
described as a weaker form of
to look at something that's often

251
00:10:30.100 --> 00:10:33.069
composition and that's aggregation see
described as a weaker form of

252
00:10:33.069 --> 00:10:38.819
you in the next video
composition and that's aggregation see