I would like to know if there is a message I can override in Pharo so that my custom classes display more descriptive information in the inspector/debuger much like simple variable types do, like Integers or Strings. For instance:
Instead of that, I would like it to show a more custom and informative description consisting of its internal variales so as to have a tighter/tidier view of the variables instead of having to click on it and open another chart (therefore losing sight of the information on the previous chart). I know you can increase the amount of charts shown below, but that is not the point of the question. I would like to achieve something like this:
I have browsed the pharo forums and found nothing, I have also tried overriding over 30 methods hoping that one of them changed the output. Only the class message seemed to change the output, but I could only return an instance of Metaclass and besides messing with this message would break a lot of stuff. Finally I tried to reverse engineer the debugger and then the inspector to see at which point is the table constructed and what values are used or which messages are sent to build said values, but it was just too much for me, the callstack kept growing and I couldn't even scratch the surface.
Luckily, doing this in any Smalltalk is very easy. Types inherited from Object are expected to answer to the message printString, and ultimately printOn: aStream. Those messages are expected to give a description of the object. So, you should just override printOn: in your class (printString uses printOn:) and all the browsers and inspectors will automatically use it. There other possibilities in Pharo, if you want to provide more complex information in different tabs, but I think printOn: will suffice for you.
An example would be:
MyPoint>>printOn: aStream
aStream nextPut: ${.
x printOn: aStream.
aStream nextPutAll: ', '
y printOn: aStream.
aStream nextPut: $}
In Smalltalk, every time you observe something you don't like or understand, you ask the question: Which message is doing this?
In your case, the question would be: Which message creates the string a MyPoint that I see everywhere?
Next, to answer your question you need to find a good place for inserting a halt and then debug from there until you find the culprit. To do this just find the simplest expression that would reproduce the issue and debug it. In your case the right-click command in the Playground will do. So,
Write and select (MyPoint on: 14 and: -5) halt in a Playground.
Right-click and issue the Print it command (I'm assuming you already checked that this command produces the string 'a MyPoint').
Debug
Go over the evaluation of #DoIt, which answers the result
Continue this way alternating between Into and Over to make sure you follow the result to where it's being taken
Eventually you will reach the implementation of Object >> #printString. Bingo!
Now you can open a System Browser and take a look at this method, study how it's been implemented in different classes, etc. Your investigation should show you that the most basic message for printing is #printOn:. You may also want to take a look at other implementors so to better understand what people usually do. (Bear in mind that writing good #printOn:s is a minimalist art)
Overriding printOn: will work for simple cases where you want to just change description.
Pharo allows a lot more than that!
Due the extensible (moldable) nature of our inspector, you do not need to override a method to get your own visualisation of the object.
For example, look this array visualisation:
This is obtained adding this method to Collection:
gtInspectorItemsIn: composite
<gtInspectorPresentationOrder: 0>
^ composite fastList
title: 'Items';
display: [ self asOrderedCollection ];
beMultiple;
format: [ :each | GTObjectPrinter asTruncatedTextFrom: each ];
send: [ :result |
result
ifNil: [ nil ]
ifNotNil: [ result size = 1
ifTrue: [ result anyOne ]
ifFalse: [ self species withAll: result ]
]
]
if you browse for senders of gtInspectorPresentationOrder: you will see there are already a lot of special visualisations in the image.
You can take those as an example on how to create your own, adapted exactly to what you need :)
Related
I am creating many games using Lua and LOVE2D, but whenever I implement a new function and want to test it out, or simply want to know a value of a variable in Lua, I either display it on the game screen or just hope that it works.
Now my question is...
IS THERE A WAY TO DISPLAY SOME INFO, such as A VARIABLE VALUE or something else into the terminal or somewhere else? Just like console.log in javascript which displays some content in the javascript console in the browser. So, is there a way to do this is Lua?? using LOVE2D?
I am using a Mac, so I have a terminal and not a command prompt. Is there a way to display some content there? Anywhere else would also be fine, I just need to see if those values are as expected or not.
Use a conf.lua file to enable the console, then you should be able to use a standard print(). You can read the wiki entry here.
Note: You have to run Lua and Love2D via the terminal for this to work. Running Lua and Love2D like this is required for the print statements to show:
/Applications/love.app/Contents/MacOS/love "/Users/myuser/Desktop/love2d-test-proj"
You just need to add a conf.lua file to the same location where your main.lua. Your file may be as simple as this:
function love.conf(t)
t.console = true
end
But feel free to copy the whole configuration file from the above link and edit what you need.
I can't be completely sure about this, because I have no access to Mac, but the console is disabled by default and even on Windows, no prints are shown until you turn it on.
Alternatively You can also display debug info in the game itself like some games do.
What I like to do is add something like debugVariable = {} for logging events that happen in each loop and debugPermanent = {} for events that happen rarely. Possibly add convenience functions for writing to the variables:
function debugAddVariable(str)
table.insert(debugVariable, str)
end
--..and similarly for debugPermanent
Now a function to draw our debug info:
function debugDraw()
love.graphics.push() --remember graphics state
love.graphics.origin() --clear any previous transforms
love.graphics.setColor(--[[select color for debug info]])
love.graphics.setFont(--[[select font for debug info]])
for i, v in ipairs(debugPermanent) do
love.graphics.print(v)
love.graphics.translate(0, --[[fontHeight]])
end
for i, v in ipairs(debugVariable) do
love.graphics.print(v)
love.graphics.translate(0, --[[fontHeight]])
end
debugVariable = {} --clear debugVariable to prepare it for the next loop
love.graphics.pop() --recall graphics state
end
And we just call this draw function at the end of our love.draw() and the texts should appear.
Obviously, this method can be refined further and further almost infinitely, displaying specific variables, and adding graphs for some other variables to clarify the information you want to show, but that's kind of outside of the scope of the question.
Lastly Feel free to check here for debug libraries submitted by users.
I have several processes with almost same flow like "Get some parameters, extract data from database according to them and upload them to target". The parameters vary slightly across processes as well as targets but only a bit. Most of the process is the same. I would like to extract those differences to parameter-context and dynamically load them. My idea is to have parameters defined following way and then using them.
So core of question is:
How to dynamically choose which parameter group load and use?
Having several parameter contexts with same-named/different-valued parameters and dynamically switching them would be probably the best, but it is not possible as far as I know.
Also duplicating flows is out-of-the-table. Any error correction would be spread out over several places and maintenance would be a nightmare.
Moreover, I know I can do it like "In GenetrateFlowFile for process A set value1=#{A_value1} and in GenetrateFlowFile for process B set value1=#{B_value1}. But this is tedious, error-prone and scales kinda bad. Not speaking of situation when I can have dozens of parameters and several processes. Also it is a kind of hardcoding, not configuring...
I was hoping for something like defining group=A and then using it like value1=#{ ${ group:append('_value1') } } but this does not work - it is evaluated as parameter literally named ${ group:append('_value1') }.
TL;DR: Use evaluateELString().
The actual solution is to set in GenetrateFlowFile processor group=A and in next UpdateAttribute processor set the following:
value1=${ group:prepend('hash{ '):append('_value1 }'):replace('hash', '#'):evaluateELString() }
The magic being done here is "Take value of group slap around it #{ and _value1 } to make it valid NiFi Expression Language statement and then evaluate it." (Notice - the word hash and function replace is there since I didn´t manage to escape the # char right before {.)
If you would like to have your value1 at the beginning of the statement then you can use following code. The result is same, it is easier to use (often-changed value value1 is at the beginning of the statement) and is less readable "what is really going on?"-wise.
value1=${ literal('value1'):prepend('_'):prepend(${ group }):prepend('hash{ '):append(' }'):replace('hash', '#'):evaluateELString() }
(It's been a while since I've been here.)
I've been using the first version of PHRets v1 for years, and understood it well enough to get by, but now I'm trying to understand the advantages of v2.6.2. I've got it all installed and the basics are working fine. My issues are pretty much with comprehending fine points of query syntax that goes into the rets=>Search() statement. (I'm much more familiar with SQL statements). Specifically, I'd like to have a query return a list of properties, EXCLUDING those which already have the status of "Sold".
Here's where I am stuck: If I start with this
`$results = $rets->Search('Property', 'A','*',['Select' => 'LIST_8,LIST_105,LIST_15,LIST_19,listing_office_shortid']);`
That works well enough. BUT I'd like to fit in a filter like:
"LIST_15 != Sold", or "NOT LIST_15=Sold"...something like that. I don't get how to fit/type that into a PHRets Search().
I like PHRets but it is so hard to find well-organized/complete documentation about specific things like this. Thanks in advance.
As in my comment above I've figured out that the filter goes in the third argument position ('*', as in the original question). The tricky thing was having to find a specific "sold" code for each class of properties and placing it in that position like so: '(LIST_15=~B4ZIT1Y75TZ)', (notice the =~ combination of characters that means "does not equal" in this context). I've found the code strings for each of the property types (not clear WHY they would need to be unique for each type of property: "Sold" is Sold for any type, after all) but the correct code for a single-family residential property (type 'A' ...at least for the MLS in which I have to search is:
$results = $rets->Search('Property', 'A','(LIST_15=~B4ZIT1Y75TZ)',['Select' => 'LIST_8,LIST_105,LIST_15,LIST_19,listing_office_shortid']);
(again, the code to go with LIST_15 will be different for the different types of properties.) I think there is a better answer that involves more naturalistic language, but this works and I guess I will have to be satisfied with it for now. I hope this is of some use to anyone else struggling with this stuff.
I am facing a debug situation like this. The oldest method I can see called is a BlockClosure newProcess.
But I need to see who originated the newProcess send. When I click over the method in the debugger method list, the stack does not expand as usually does showing the callers.
Is this possible in Pharo?
Short answer: no. A new process doesn't have any history from before its conception.
Slightly longer answer: if you're willing to do a little work you can embed a reference to the caller process in the new process by using the normal closure creation. Here's an example:
| currentStack forkedProcess |
currentStack := thisContext copyStack.
forkedProcess := [
| referenceToCaller |
referenceToCaller := currentStack.
self performOperations ] fork.
Note that this will not enhance your debugging experience since the debugger doesn't know that you have that reference. To do this you need to extend the stack of your current process (variant of the above):
forkedProcess := [
thisContext bottomContext privSender: currentStack.
self performOperations ] fork.
Be very careful when manipulating the context chain like this. You may end up in situations that are hard to understand and debug. What I've shown here is for illustration and shouldn't be used if you don't know how the system works.
I want to use primitive type for describe data structure. Like so:
# Data Structures
## Video Delete (enum[number])
+ `0` - Successful deletion.
+ `1` - Error occured.
And the output is.
{
"enum": [
1,
0
],
"$schema": "http://json-schema.org/draft-04/schema#"
}
So description is missing. I've tried to put description in different places. I did a lot of things (do not wanna talk about them). Also I've tried to add info to enum values like so:
+ `0` (number) - Successful deletion.
I do not know whether this problem deals with MSON syntax or Aglio generator.
The syntax above is supported by MSON as far as I can tell. The problem is that Aglio doesn't do anything with the description, and when I went to look into adding it I realized that it isn't really supported in JSON Schema. There seem to be two methods people use to get around that fact:
Add the enumerated value descriptions to the main description, the Olio theme 1.6.2 has support for this but the C++ parser seems to still have some bugs around this feature:
## Video Delete (enum[number]) - 0 for success, 1 for error
Use a weird oneOf syntax where you create sets of single enums with a description. I don't recommend this.
Unfortunately the first option requires work on your part and can't easily be done in Aglio. Does anyone else have a better description and some samples of MSON input -> JSON Schema output?