Widget in flutter similar to android <merge> - flutter-layout

Is there a widget similar with <merge> tag in android?
It has multiple widgets as its children, but behave same with this widget's parent, something like:
Row(children: [a, X(children: [c1, c2, c3]), b], (a, c1, c2, c3, b) are all in a row;
Column(children: [a, X(children: [c1, c2, c3]), b], (a, c1, c2, c3, b) are all in a column;
Wrap(children: [a, X(children: [c1, c2, c3]), b], (a, c1, c2, c3, b) are all in a wrap;


Flutter utilizes widget which are composable as such there is no need for Xml tags like Merge or FrameLayout, wrap your widget on one page with a stateless or stateful widget and include the class name in the parent build function.

Related

Cassandra soft deletes on tables with only partial partition key known

I have multiple tables with a combination of A, B, C entities as part of partition keys.
Table 1: columns A, B, C, D, E, F, G, H
Primary key ((A, B, C, Date), D, E)
rows-> A1, B1, C1, 07-09-2020, D1, E1 ....
A1, B1, C1, 07-10-2020, D1, E1 ....
A1, B2, C1, 07-10-2020, D2, E1 ....
.....
Table 2: columns A, B, C, D, E, F, G, H
Primary key ((B, C, Created_timestamp, A), D, E)
rows-> B1, C1, 07-09-2020 05:02:01Z, A1, D1, E1 ....
B1, C1, 07-10-2020 02:02:01Z, A1, D1, E1 ....
B2, C1, 07-10-2020 06:02:01Z, A1, D2, E1 ....
.....
Table 3: columns A, B, C, D, E, F, G, H
Primary Key ((B, A), C)
rows -> B1, A1, C1 ...
B2, A1, C2 ...
....
Table 4: columns A, B, C, D, E, F, G, H
Primary Key ((F, C), A)
rows -> F1, C1, A1 ...
F1, C2, A1 ...
....
Now let's say if A1 is to be deleted in the system then all rows corresponding to A1 in all the tables should be marked as deleted (no TTL is to be used).
P.S - By pointing to above tables all I wanted to show was the position of A varies in the partition key and as well as in the primary key as a whole.

When deleting record for Table 1, at least the values of column A,B,C are known. So I think you need another 2 look up tables to achieve it
Lookup Table for Table 2
Columns - A, B, C,D, E, Created_timestamp
Primary key - ((A, B, C), Created_timestamp, D, E)
Lookup Table for Table 4
Columns - F, C, A
Primary key - ((A, C), F)
Once you have fetched the primary keys for table 2 and table 4, you have the primary keys for them to delete it,

Add variable amount of columns to a table

I am doing a project where I am not sure how many columns I will need.
For example, one column I might have is,
(1, xyz, c1, c2, c3, c4)
and the other might have
(2, xyz, c1, c2, c3, c4, c5, c6)
I am not sure what to do, thanks!

Output text Yes or No if cell has a, and (b or C) and d in Excel

Cell a1 has letters a, b, c, d, e. I want to output in cell a2 yes or no based on what is identified in cell a1.
I can do: output yes if a, and b, and C are found in a1 by:
=IF(AND(ISNUMBER(SEARCH("*a*",A1)),ISNUMBER(SEARCH("*b*",A1)),ISNUMBER(SEARCH("*c*",A1))),"yes","no")
But I cannot do: output yes if a, and (b or C), and D are found in a1...
What formulae modification should I make?

Consider:
=IF(AND(ISNUMBER(SEARCH("a",A1)),ISNUMBER(SEARCH("b",A1)),OR(ISNUMBER(SEARCH("c",A1)),ISNUMBER(SEARCH("d",A1)))),"yes","no")

You can use and() and or() too.
=IF(AND(ISNUMBER(SEARCH("a", A1)),
OR(ISNUMBER(SEARCH("b", A1)), ISNUMBER(SEARCH("c", A1))),
ISNUMBER(SEARCH("d", A1))), "yes", "no")

Get all combinations of the first column's value and other column's value

I have an irregular table in Excel:
A A1 A2 A3
B B1
C C1 C2 C3 C4
...
How can I get the following its representation?
A A1
A A2
A A3
B B1
C C1
C C2
C C3
C C4
...

This answer in SuperUser to Transform horizontal table layout to vertical table using VBA appears to give exactly what you are looking for.
The code is self explanatory by virtue of working step by step.
Hope it helps.

UML diagram - Composition

Could someone help me out with this UML diagram?
Given this UML diagram, suppose that at runtime, we have created objects a1 and a2 from class A, b1 and b2 from class B, c1 and c2 from class C, d1 and d2 from class D, e1 and e2 from class E. Which one of these situations could happen at runtime?
a. e1 contains d1, and d1 contains e2, and e2 contains b2
b. a1 contains c1, and c1 contains d1
c. b1 contains d1, and d1 contains e2
d. c1 contains a1, and a1 contains b1
I haven't been able to solve this, as I tend to think that both b) and d) are possible.

a) is the correct answer.
b) is false, as a1 can't contain anything
c) is false, because b1 can't contain anything
d) is false, a1 can't contain anything
Description: C and it's children (D,E) can contain any class of this hierarchy as it can contain children of A

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