Does anyne know how expression engine deals with a negative offset in a list of channel entries in EE?
as in
offset="-1"
If you use offset="-1" in {exp:channel:entries}, you'll get a major MySQL error (assuming you're logged in as a super admin or are capable of seeing errors).
It's unclear what your goal is from your question. If you expect a negative offset to reverse the order (like PHP string functions), you can use use the opposite sort value. The default is desc, so sort="asc" would be the reverse. Use a positive offset="X" to skip X entries.
If you're expecting an offset like in PHP array_slice where you're still going "forward" but a negative offset starts you X entries from the end, I don't believe there's a direct comparison.
The goal was to work with the preceding chanel entry on the same page as the current channel entry.
I managed to do it instead by pulling out the relevant entry_ids and processing them in php and then put them back in with a fixed_order attribute
Related
I have different commands my program is reading in (i.e., print, count, min, max, etc.). These words can also include a number at the end of them (i.e., print3, count1, min2, max6, etc.). I'm trying to figure out a way to extract the command and the number so that I can use both in my code.
I'm struggling to figure out a way to find the last element in the string in order to extract it, in Smalltalk.
You didn't told which incarnation of Smalltalk you use, so I will explain what I would do in Pharo, that is the one I'm familiar with.
As someone that is playing with Pharo a few months at most, I can tell you the sheer amount of classes and methods available can feel overpowering at first, but the environment actually makes easy to find things. For example, when you know the exact input and output you want, but doesn't know if a method already exists somewhere, or its name, the Finder actually allow you to search by giving a example. You can open it in the world menu, as shown bellow:
By default it seeks selectors (method names) matching your input terms:
But this default is not what we need right now, so you must change the option in the upper right box to "Examples", and type in the search field a example of the input, followed by the output you want, both separated by a ".". The input example I used was the string 'max6', followed by the desired result, the number 6. Pharo then gives me a list of methods that match that:
To get what would return us the text part, you can make a new search, changing the example output from number 6 to the string 'max':
Fortunately there is several built-in methods matching the description of your problem.
There are more elegant ways, I suppose, but you can make use of the fact that String>>#asNumber only parses the part it can recognize. So you can do
'print31' reversed asNumber asString reversed asNumber
to give you 31. That only works if there actually is a number at the end.
This is one of those cases where we can presume the input data has a specific form, ie, the only numbers appear at the end of the string, and you want all those numbers. In that case it's not too hard to do, really, just:
numText := 'Kalahari78' select: [ :each | each isDigit ].
num := numText asInteger. "78"
To get the rest of the string without the digits, you can just use this:
'Kalahari78' withoutTrailingDigits. "Kalahari"6
As some of the Pharo "OGs" pointed out, you can take a look at the String class (just type CMD-Return, type in String, hit Return) and you will find an amazing number of methods for all kinds of things. Usually you can get some ideas from those. But then there are times when you really just need an answer!
I have a dataset with data collected from a form that contains various date and value fields. Not all fields are mandatory so blanks are possible and
in many cases expected, like a DeathDate field for a patient who is still alive.
How do I best represent these blanks in the data?
I represent DeathDate using xsd:dateTime. Blanks or empty spaces are not allowed. All of these are flagged as invalid when validating using Jena RIOT:
foo:DeathDate_1
a foo:Deathdate ;
time:inXSDDatetime " "^^xsd:dateTime .
foo:DeathDate_2
a foo:Deathdate ;
time:inXSDDatetime ""^^xsd:dateTime .
foo:DeathDate_3
a foo:Deathdate ;
time:inXSDDatetime "--"^^xsd:dateTime .
I prefer to not omit the triple because I need to know if it was blank on the source versus a conversion error during construction of my RDF.
What is the best way to code these missing values?
You should represent this by just omitting the triple. That's the meaning of a triple that's "not present": it's information that is (currently) unknown.
Alternatively, you can choose to give it the value "unknown"^^xsd:string when there's no death date. The solution in this case is to not datatype it as an xsd:dateTime, but just as a simple string. It doesn't have to be a string of course, you could use any kind of "special" value for this, e.g. a boolean false - just as long as it's a valid literal value that you can distinguish from actual death dates. This will solve the parsing problem, but IMHO if you do this, you are setting yourself up for headaches in processing the data further down the line (because you will need to ask queries over this data, and they will have to take two different types of values into account, plus the possibility that the field is missing).
I prefer to not omit the triple because I need to know if it was blank
on the source versus a conversion error during construction of my RDF.
This sounds like an XY problem. If there are conversion errors, your application should signal that in another way, e.g. by logging an error. You shouldn't try to solve this by "corrupting" your data.
I'm new to ANTL4 and I can't seem to figure out how to get lexer actions to perform properly.
I have a code snippet that looks for input text:
SIZE10 : [a-zA-Z]* {getText().length() <= 10}?
I would expect that it does not match any combinations of letters that are over 10 letters long, however what this does is treat a 10+ letter string as two different tokens, instead of just nullifying the whole set of 10+ letters. How can I get this action to nullify the whole set of letters?
In addition, where can I go to see all the different token functions I can use (other than getText())? The documentation about lexer actions is really poor. In general, I'm having a hard time figuring out what resources can give me a definitive list of everything in the language. Even an entry point into the source code for me to read would be good at this point. The documentation is too general/basic for me.
EDIT: I've figured out how to send a RuntimeException, but I don't know where to get the elements needed for a proper RecognitionException.
The predicate in a rule directs the parsing process in a way that allows to match only partial input (like in your case) or essentially switch off a part of the grammar depending on certain conditions. In your case the SIZE10 rule is matched until the predicate returns false. Everything up to this event is then returned as a match for SIZE10. After that lexing continues at the point it ended for the previous token and if that is again a letter it will again match SIZE10 as long as the predicate says it is correct. That's a bit different than what you would expect (e.g. using the predicate as an all or nothing switch).
However, if you instead want to match the full set of letters first and then check if the length is <= 10 you can do this in a listener. You can hook into the exitSIZE10() event and reject the match by throwing a recognition exception.
For the usable functions in your actions see the API documentation for ANTLR. For instance here is the one for Token which shows you other possibilities beside getText(). In your action, consider the context you have. In a lexer rule you deal with a Token, hence getText() etc. work on the token. In a parser rule you have a ParserContext instead, which also has a getText() function but that works differently (collecting all child contexts text into a comma separated list).
I am newest in Lucene.
I'm using Lucene.NET version 2.9.4.
What is the difference between these queries?
the first is:
title:hello AND tags:word
the second is:
+title:hello +tags:word
I testing a software, and I note that the first returns 3 records, and the second returns many records.
I observe that the first returns records where title and tags fields are fuel, but the second returns records where title and tags can be empty.
Is it the difference?
There is no difference between the two. clause1 AND clause2 is effectively shorthand for +clause1 +clause2
Similarly: clause1 clause2 = clause1 OR clause2
Note, there is really no equivalent for +clause1 clause2 using the boolean operators.
Are you sending the query over the Internet, if you are and not urlencoding the request correctly it could be misinterting the '+' as an encoded space and therefore lucene just runs the second query as if the +'s not there which would just OR the two parts and give the results you get.
title:hello tags:word
I have a LaTeX document where I'd like the numbering of floats (tables and figures) to be in one numeric sequence from 1 to x rather than two sequences according to their type. I'm not using lists of figures or tables either and do not need to.
My documentclass is report and typically my floats have captions like this:
\caption{Breakdown of visualisations created.}
\label{tab:Visualisation_By_Types}
A quick way to do it is to put \addtocounter{table}{1} after each figure, and \addtocounter{figure}{1} after each table.
It's not pretty, and on a longer document you'd probably want to either include that in your style sheet or template, or go with cristobalito's solution of linking the counters.
The differences between the figure and table environments are very minor -- little more than them using different counters, and being maintained in separate sequences.
That is, there's nothing stopping you putting your {tabular} environments in a {figure}, or your graphics in a {table}, which would mean that they'd end up in the same sequence. The problem with this case (as Joseph Wright notes) is that you'd have to adjust the \caption, so that doesn't work perfectly.
Try the following, in the preamble:
\makeatletter
\newcounter{unisequence}
\def\ucaption{%
\ifx\#captype\#undefined
\#latex#error{\noexpand\ucaption outside float}\#ehd
\expandafter\#gobble
\else
\refstepcounter{unisequence}% <-- the only change from default \caption
\expandafter\#firstofone
\fi
{\#dblarg{\#caption\#captype}}%
}
\def\thetable{\#arabic\c#unisequence}
\def\thefigure{\#arabic\c#unisequence}
\makeatother
Then use \ucaption in your tables and figures, instead of \caption (change the name ad lib). If you want to use this same sequence in other environments (say, listings?), then define \the<foo> the same way.
My earlier attempt at this is in fact completely broken, as the OP spotted: the getting-the-lof-wrong is, instead of being trivial and only fiddly to fix, absolutely fundamental (ho, hum).
(For the afficionados, it comes about because \advance commands are processed in TeX's gut, but the content of the .lof, .lot, and .aux files is fixed in TeX's mouth, at expansion time, thus what was written to the files was whatever random value \#tempcnta had at the point \caption was called, ignoring the \advance calculations, which were then dutifully written to the file, and then ignored. Doh: how long have I know this but never internalised it!?)
Dutiful retention of earlier attempt (on the grounds that it may be instructively wrong):
No problem: try putting the following in the preamble:
\makeatletter
\def\tableandfigurenum{\#tempcnta=0
\advance\#tempcnta\c#figure
\advance\#tempcnta\c#table
\#arabic\#tempcnta}
\let\thetable\tableandfigurenum
\let\thefigure\tableandfigurenum
\makeatother
...and then use the {table} and {figure} environments as normal. The captions will have the correct 'Table/Figure' text, but they'll share a single numbering sequence.
Note that this example gets the numbers wrong in the listoffigures/listoftables, but (a) you say you don't care about that, (b) it's fixable, though probably mildly fiddly, and (c) life is hard!
I can't remember the syntax, but you're essentially looking for counters. Have a look here, under the custom floats section. Assign the counters for both tables and figures to the same thing and it should work.
I'd just use one type of float (let's say 'figure'), then use the caption package to remove the automatically added "Figure" text from the caption and deal with it by hand.