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How do I avoid capturing self in blocks when implementing an API?
...Complete];
}
The __block keyword marks variables that can be modified inside the block (we're not doing that) but also they are not automatically retained when the block is retained (unless you are using ARC). If you do this, you must be sure that nothing else is going to try to execute the block ...
Load local JSON file into variable
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If you pasted your object into content.json directly, it is invalid JSON. JSON keys and values must be wrapped in double quotes (" not ') unless the value is numeric, boolean, null, or composite (array or object). JSON cannot contain functions or undefined values. Below is your object as v...
CSS: How to have position:absolute div inside a position:relative div not be cropped by an overflow:
...ext/css">
/* Positioning */
#box1 { overflow: hidden }
#box2 { position: absolute }
#box3 { position: absolute; top: 10px }
/* Styling */
#box1 { background: #efe; padding: 5px; width: 125px }
#box2 { background...
How to set the text color of TextView in code?
In XML, we can set a text color by the textColor attribute, like android:textColor="#FF0000" . But how do I change it by coding?
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What is the advantage of using REST instead of non-REST HTTP?
...ons about how to use HTTP . I wonder which advantage these conventions provide. Does anyone know?
14 Answers
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Can't access object property, even though it shows up in a console log
...ess, but on the very next line of code, I can't access it with config.col_id_3 (see the "undefined" in the screenshot?). Can anyone explain this? I can get access to every other property except field_id_4 as well.
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What is the colon operator in Ruby?
...bols have the distinct feature that any two symbols named the same will be identical:
"foo".equal? "foo" # false
:foo.equal? :foo # true
This makes comparing two symbols really fast (since only a pointer comparison is involved, as opposed to comparing all the characters like you would in a st...
SQLAlchemy: What's the difference between flush() and commit()?
...abase until they are committed (if your program aborts for some reason in mid-session transaction, any uncommitted changes within are lost).
The session object registers transaction operations with session.add(), but doesn't yet communicate them to the database until session.flush() is called.
se...
Generate a random number in the range 1 - 10
Since my approach for a test query which I worked on in this question did not work out, I'm trying something else now. Is there a way to tell pg's random() function to get me only numbers between 1 and 10?
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How to select the row with the maximum value in each group
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A dplyr solution:
library(dplyr)
ID <- c(1,1,1,2,2,2,2,3,3)
Value <- c(2,3,5,2,5,8,17,3,5)
Event <- c(1,1,2,1,2,1,2,2,2)
group <- data.frame(Subject=ID, pt=Value, Event=Event)
group %>%
group_by(Subject) %>%
summarize(max.pt = max(...