I'm using prototype and have some divs with id p1 p2 p3...
In these divs I have some divs with id d1 d2 d3...
I would like to use $ to get the specified d element, in the specified p element.
If I'm given the values 3 and 4 I should be able to go $('p3').$('d4')
This syntax doesn't work of course.
There's an easy way to do this with jQuery so I'm assuming this exists in prototype
Unfortunately, prototype's $ function doesn't chain, as it returns an extended HTMLElement object and $ is a window method. However, you could use the $$ function along with a CSS selector to achieve this:
$$('#p3 #d4').first(); // Element with id 'd4' that's a descendant of an element with id 'p3'
While the $$ function returns an extended HTMLElement object just like $, it actually returns an array of them, as a CSS selector could potentially match multiple elements.
You can read about CSS selectors here.
Considering an id ("identifier") is (should be) unique, why not just use the most specific identifier you have -- the second one :
$('d4')
If your identifiers are not unique, they are not identifiers... And they shouldn't be used as the "id" attribute of your divs...
Actually, if you have something like this :
p1
d1
d2
p2
d1
d2
d3
p3
d1
Your "pX" can be id (they are unique), but your "dX" shouldn't be ids ; a solution might be to use the class to store the "dX" information.
A bit like this, I suppose :
id=p1
class=d1
class=d2
id=p2
class=d1
class=d2
class=d3
id=p3
class=d1
Then, you'll use the $$ function with a CSS-selector : if you want the element with a class="d2" inside the elemnt of id="p1", something like this might work :
$$('#p1 .d2');
ie :
p1 = element with id=p1
.d2 = element which has a class containing d2
Hope this is clear and helps...
This ought to work:
$('p3').select('#d4').first()
Then again, if all of your ids are unique, as they should be, why not just do this:
$('d4');
$('p3').select(new Selector('#d4'));
Related
I try to create many components depending on the value of constant elements. These elements are organized in an array of records.
Dymola prints the translation log for the example below:
But I'm sure to use fixed conditions because I only perform allowed operations on constant values.
Here is the simple example of what I wantet to do:
model ConditionalComponent
type Enum = enumeration(one,two,three);
record Tmp
parameter Integer ID;
parameter Boolean active;
end Tmp;
record TmpNamed
parameter Enum name;
extends Tmp;
end TmpNamed;
function reorder
input TmpNamed inp[:];
output Tmp out[size(inp,1)];
algorithm
for elem in inp loop
out[elem.name] := Tmp(elem.ID, elem.active);
end for;
end reorder;
constant TmpNamed testIn[:] = {
TmpNamed(Enum.two,20,true),
TmpNamed(Enum.one,10,true),
TmpNamed(Enum.three,30,true)};
constant Tmp testOut1[:] = reorder({
TmpNamed(Enum.two,20,true),
TmpNamed(Enum.one,10,true),
TmpNamed(Enum.three,30,true)});
constant Tmp testOut2[:] = reorder(testIn);
constant Boolean active1 = testOut1[Enum.one].active;
constant Boolean active2 = testOut2[Enum.one].active;
Real t1=0 if testOut1[Enum.one].active;
//Real t2=0 if testOut2[Enum.one].active;
//Real t3=0 if active1;
//Real t4=0 if active2;
end ConditionalComponent;
The function reorder is intended to ease the management of large lists of named active components. Normally the constant testOut2 is used and created within the package ConditionalComponent. But for testing purposes ConditionalComponent is a model here. Actually I only want to use the line
Real t2=0 if testOut2[choice].active;
parameter Enum choice = Enum.one;
within other components, that have a parameter of type Enum. The declarations for t1, t3, t4 are only some tests that work, depending on what is left uncommented.
For example leaving the declaration for t1 and t3 uncommented works. But if one uses only the declaration for t1, it is not translated by Dymola.
The difference between t1 and t2 is, that the argument for reorder is passed directly or via the constant testIn.
I'm sure, that most parameter and constant prefixes are unnecessary and I tried hard to figure out the problem. But unfortunately I cannot decide whether Dymola is not working correctly or I did something wrong. And I've got no idea how to debug the translation process to figure it out by myself.
Can anyone tell me, what am I doing wrong?
Not something wrong, but it's just currently seen as too complicated and not handled.
A work-around is to split subscripting and element access:
constant Tmp testOut1_one=testOut1[Enum.one];
Real t1=0 if testOut1_one.active;
I am having a couple of issues to put this in a functional format.
select from tableName where i=fby[(last;i);([]column_one;column_two)]
This is what I got:
?[tableName;fby;enlist(=;`i;(enlist;last;`i);(+:;(!;enlist`column_one`column_two;(enlist;`column_one;`column_two))));0b;()]
but I get a type error.
Any suggestions?
Consider using the following function, adjust from the buildQuery function given in the whitepaper on Parse Trees. This is a pretty useful tool for quickly developing in q, this version is an improvement on that given in the linked whitepaper, having been extended to handle updates by reference (i.e., update x:3 from `tab)
\c 30 200
tidy:{ssr/[;("\"~~";"~~\"");("";"")] $[","=first x;1_x;x]};
strBrk:{y,(";" sv x),z};
//replace k representation with equivalent q keyword
kreplace:{[x] $[`=qval:.q?x;x;"~~",string[qval],"~~"]};
funcK:{$[0=t:type x;.z.s each x;t<100h;x;kreplace x]};
//replace eg ,`FD`ABC`DEF with "enlist`FD`ABC`DEF"
ereplace:{"~~enlist",(.Q.s1 first x),"~~"};
ereptest:{((0=type x) & (1=count x) & (11=type first x)) | ((11=type x)&(1=count x))};
funcEn:{$[ereptest x;ereplace x;0=type x;.z.s each x;x]};
basic:{tidy .Q.s1 funcK funcEn x};
addbraks:{"(",x,")"};
//where clause needs to be a list of where clauses, so if only one whereclause need to enlist.
stringify:{$[(0=type x) & 1=count x;"enlist ";""],basic x};
//if a dictionary apply to both, keys and values
ab:{$[(0=count x) | -1=type x;.Q.s1 x;99=type x;(addbraks stringify key x),"!",stringify value x;stringify x]};
inner:{[x]
idxs:2 3 4 5 6 inter ainds:til count x;
x:#[x;idxs;'[ab;eval]];
if[6 in idxs;x[6]:ssr/[;("hopen";"hclose");("iasc";"idesc")] x[6]];
//for select statements within select statements
//This line has been adjusted
x[1]:$[-11=type x 1;x 1;$[11h=type x 1;[idxs,:1;"`",string first x 1];[idxs,:1;.z.s x 1]]];
x:#[x;ainds except idxs;string];
x[0],strBrk[1_x;"[";"]"]
};
buildSelect:{[x]
inner parse x
};
We can use this to create the functional query that will work
q)n:1000
q)tab:([]sym:n?`3;col1:n?100.0;col2:n?10.0)
q)buildSelect "select from tab where i=fby[(last;i);([]col1;col2)]"
"?[tab;enlist (=;`i;(fby;(enlist;last;`i);(flip;(lsq;enlist`col1`col2;(enlist;`col1;`col2)))));0b;()]"
So we have the following as the functional form
?[tab;enlist (=;`i;(fby;(enlist;last;`i);(flip;(lsq;enlist`col1`col2;(enlist;`col1;`col2)))));0b;()]
// Applying this
q)?[tab;enlist (=;`i;(fby;(enlist;last;`i);(flip;(lsq;enlist`col1`col2;(enlist;`col1;`col2)))));0b;()]
sym col1 col2
----------------------
bah 18.70281 3.927524
jjb 35.95293 5.170911
ihm 48.09078 5.159796
...
Glad you were able to fix your problem with converting your query to functional form.
Generally it is the case that when you use parse with a fby in your statement, q will convert this function into its k definition. Usually you should just be able to replace this k code with the q function itself (i.e. change (k){stuff} to fby) and this should run properly when turning the query into functional form.
Additionally, if you check out https://code.kx.com/v2/wp/parse-trees/ it goes into more detail about parse trees and functional form. Additionally, it contains a script called buildQuery which will return the functional form of the query of interest as a string which can be quite handy and save time when a functional form is complex.
I actually got it myself ->
?[tableName;((=;`i;(fby;(enlist;last;`i);(+:;(!;enlist`column_one`column_two;(enlist;`column_one;`column_two)))));(in;`venue;enlist`venueone`venuetwo));0b;()]
The issues was a () missing from the statement. Works fine now.
**if someone wants to add a more detailed explanation on how manual parse trees are built and how the generic (k){} function can be replaced with the actual function in q feel free to add your answer and I'll accept and upvote it
DECLARE A,B;
DECLARE Annotation C(Annotation firstA, Annotation secondA,...);
"token1|token2|...|tokenn" -> A;
"token3|token4" -> B;
A A B {->MARK(C,1,3)};
I did with GATHER
(A COMMA A B) {-> GATHER(C,1,4,"firstA"=1,"secondA" = 3,"B"=4)};
But how about in case of unknown sequence of A type? as below, how can it be possible to store all A in features? The number of features are also unknown. In plan java, we declare String array and can add element, but in Ruta seems to be no as such process.
(A (COMMA A)+ B) {-PARTOF(C) -> GATHER(C,beginPosition,endPosition,"firstA"=1,"secondA" = 3,"thirdA"=?,so on)};
Annotations in UIMA refer to the complete span, from the begin offset to the end offset. So, if you want to specify something with two elements, then a simple annotation is not sufficient. You cannot create an annotation of the type C that covers the first A and the B but not the second A.
However, you can store the important information in feature values. How to implement it depends on various things.
If there are always exactly two annotation you want to remember, then add two features to type C and assign the feature values in the given rule, e.g., by CREATE(C,1,3,"first" = A, "second" = B ).
You can also use different actions like GATHER, or use one FSArray feature in order to store the annotations.
A complete example with a FSArray:
DECLARE A, B;
DECLARE Annotation C (FSArray as, B b);
"A" -> A;
"B" -> B;
(A (COMMA A)+ B){-PARTOF(C) -> CREATE(C, "as" = A, "b" = B)};
If applied on a text like "A, A, A B", the last rule creates one annotation of type C that stores three A annotations in the feature "as" and one B annotation in the feature "b"
I have a Matlab structure like this:
Columns.T21=6;
Columns.ws21=9;
Columns.wd21=10;
Columns.u21=11;
Is there some elegant way I can give the value and return the field name? For instance, if I give 6 and it would return 'T21.' I know that fieldnames() will return all the field names, but I want the fieldname for a specific value. Many thanks!
Assuming that the structure contains fields with scalar numeric values, you can use this struct2array based approach -
search_num = 6; %// Edit this for a different search number
fns=fieldnames(Columns) %// Get field names
out = fns(struct2array(Columns)==search_num) %// Logically index into names to find
%// the one that matches our search
Goal:
Construct two vectors from your struct, one for the names of fields and the other for their respective values. This has analogy to the dict in Python or map in C++, where you have unique keys being mapped to possibly non-unique values.
Simple Solution:
You can do this very simply using the various functions defined for struct in Matlab, namely: struc2cell() and cell2mat()
For the particular element of interest, say 1 of your struct Columns, get the names of all fields in the form of a cell array, using fieldnames() function:
fields = fieldnames( Columns(1) )
Similarly, get the values of all the fields of that element of Columns, in the form of a matrix
vals = cell2mat( struct2cell( Columns(1) ) )
Next, find the field with the corresponding value, say 6 here, using the find function and convert the resulting 1x1 cell into a char using cell2mat() function :
cell2mat( fields( find( vals == 6 ) ) )
which will yield:
T21
Now, you can define a function that does this for you, e.g.:
function fieldname = getFieldForValue( myStruct, value)
Advanced Solution using Map Container Data Abstraction:
You can also choose to define an object of the containers.map class using the field-names of your struct as the keySet and values as valueSet.
myMap = containers.Map( fieldnames( Columns(1) ), struct2cell( Columns(1) ) );
This allows you to get keys and values using corresponding built-in functions:
myMapKeys = keys(myMap);
myMapValues = values(myMap);
Now, you can find all the keys corresponding to a particular value, say 6 in this case:
cell2mat( myMapKeys( find( myMapValues == 6) )' )
which again yields:
T21
Caution: This method, or for that matter all methods for doing so, will only work if all the fields have the values of the same type, because the matrix to which we are converting vals to, need to have a uniform type for all its elements. But I assume from your example that this would always be the case.
Customized function/ logic:
struct consists of elements that contain fields which have values, all in that order. An element is thus a key for which field is a value. The essence of "lookup" is to find values (which are non-unique) for specific keys (which are unique). Thus, Matlab has a built-in way of doing so. But what you want is the other way around, i.e. to find keys for specific values. Since its not a typical use case, you need to write up your own logic or function for it.
Suppose your structure is called S. First extract all the field names into an array:
fNames=fieldnames(S);
Now define a following anonymous function in your code:
myfun=#(yourArray,desiredValue) yourArray==desiredValue;
Then you can get the desired field name as:
desiredFieldIndex=myfun(structfun(#(x) x,S),3) %desired value is 3 (say)
desiredFieldName=fNames(desiredFieldIndex)
Alternative using containers.Map
Assuming each field in the structure contains one scalar value as in the question (not an array).
Aim is to create a Map object with the field values as keys and the field names as values
myMap = containers.Map(struct2cell(Columns),fieldnames(Columns))
Now to get the fieldname for a value index into myMap with the value
myMap(6)
ans =
T21
This has the advantage that if the structure doesn't change you can repeatedly use myMap to find other value-field name pairs
Although I know about splats, still I can't quite grasp the last line from the following code:
class Borrowable extends Decorator
constructor: (#libraryItem) ->
removeBorrower: (borrower) ->
#borrowers[t..t] = [] if ( t = #borrowers.indexOf(borrower) ) > -1
Btw, this code was copied from https://github.com/aksharp/Design-Patterns/blob/master/CoffeeScript/Decorator.coffee
Im assuming this is Destructuring Assignment, still I can't quite get my head around what's it's happening behind the scenes.
Could you help clarify this?
Let's have a closer look at the last line:
#borrowers[t..t] = [] if ( t = #borrowers.indexOf(borrower) ) > -1
I'm not sure if this form counts as Destructuring Assignment, probably it is.
First, it calls #borrowers.indexOf(borrower) to check that borrower is present inside of the #borrowers array and to get it's index.
It's conventional to use borrower in #borrowers form instead of #borrowers.indexOf(borrower) > -1, but in this case we need index of an element as well.
If borrower is present in #borrowers, it gets the part of the #borrowers array between indexes t and t
#borrowers[t..t]
which is the [borrower], and assigns it to the empty array [], thus removing the borrower from #borrowers array.
Here is js-like equivalent of this assignment:
#borrowers.splice t, 1