We had the following code to retrieve data of type TYPE through a model, which is a custom proxy model. This is required by the next QSortFilterProxyModel to make the decision about filtering of elements. The code is actually combined from 2 functions: in the project we usually have some arbitrary index related to some ROW and use it to retrive the data from another predefined column which contains TYPE data.
QModelIndex index = sourceModel()->index(row, COLUMN1, sourceParent); /* sourceParent is always'invalid' - retrieving data from top-level items*/
ModelIndex sibling = index.sibling(row, COLUMN2);
return sibling.data(Qt::EditRole).value<TYPE>();
This worked fine with Qt4 but when moved to Qt5 sibling became 'invalid'. I wonder what has happened, taking into account that the data is actually there, which I see, by changing the code to the following
return sourceModel()->index(sourceRow, COLUMN2, sourceParent).data(Qt::EditRole).value<TYPE>();
-works fine
Looking at the implementation of sibling(), I cannot tell what makes it return an invalid index in your case. Comparing with the Qt4 implementation, maybe it's around the IndexMap use.
But why don't you simply use your solution with sourceModel()->index(sourceRow, COLUMN2, sourceParent), since it already seems to be what you actually want to do?
Related
I'm planning to overwrite a Field value using pandas but that does not seem to work. Am i missing anything as part of the code below?
`for row_no in range(df.shape[0]):
rowIndex = df.index[row_no]
if re.search('Fex|Process|PIP|VIP|Generic|Mobility', df.loc[rowIndex].VPC_Sub_Cat, re.I):
print(df.loc[rowIndex].Headline)
print(df.loc[rowIndex].VPC_Sub_Cat)
print(df.loc[rowIndex].Final_Result)
df.loc[rowIndex].Final_Result = 0
print(df.loc[rowIndex].Final_Result)
break`
The output that I get after running this piece of code is:
This is the description of the issue...
VPC-Generic
1
1
Also can i achieve the same thing using a function and applying that on a data frame? kindly let me know.
df.loc[rowIndex].Final_Result is equals to (in most situation though...)
df.loc[rowIndex]['Final_Result']
This will cause a chained assignment (see here #Warning)
Whether a copy or a reference is returned for a setting operation, may depend on the context. This is sometimes called chained assignment and should be avoided. See Returning a View versus Copy.
And then from Returning a view versus a copy
But it turns out that assigning to the product of chained indexing has inherently unpredictable results.
So using df.loc[rowIndex, 'Final_Result'] to make sure that the value you assigned is view, not copy.
As far as I understand, it is not possible in Appian to dynamically construct (process) variable names, just like you would do e.g. with bash using backticks like MY_OBJECT=pv!MY_CONS_`extract(valueOfPulldown)`. Is that correct? Is there a workaround?
I have set of Appian constants, let's call them MY_CONS_FOO, MY_CONS_BAR, MY_CONS_LALA, all of which are e.g. refering to an Appian data store entity. I would like to write an Appian expression rule which populates another variable MY_OBJECT of the same type (here: data store entity), depending e.g. of the options of a pull-down menu having the possible options stored in an array MY_CONS_OPTIONS looking as follows
FOO
BAR
LALA
I could of course build a lengthy case-structure which I have to maintain in addition to MY_CONS_OPTIONS, so I am searching for a more dynanmic approach using the extract() function depending on valueOfPulldown as the chosen value of the pulldown-menu.
Edit: Here the expression-rule (in pseudo-code) I want to avoid:
if (valueOfPulldown = 'FOO') then MY_OBJECT=pv!MY_CONS_FOO
if (valueOfPulldown = 'BAR') then MY_OBJECT=pv!MY_CONS_BAR
if (valueOfPulldown = 'LALA') then MY_OBJECT=pv!MY_CONS_LALA
The goal is to be able to change the data store entity via pulldown-menu.
This can help you find what is behind your constant.
fn!typeName(fn!typeOf(cons!YOUR_CONSTANT)).
Having in mind additional details I would do as follows:
Create separate expression that will combine details into list of Dictionary like below:
Expression results (er):
{
{dd_label: "label1", dd_value: 1, cons: "cons!YOUR_CONSTANT1" }
,{dd_label: "label2", dd_value: 2, cons: "cons!YOUR_CONSTANT2" }
}
on UI for your dropdown control use er.dd_label as choiceLabels and er.dd_value as choiceValues
when user selects value on Dropdown save dropdown value to some local variable and then use it to find your const by doing:
property( index(er, wherecontains(local!dropdownselectedvalue, tointeger(er.dd_value))), "cons")
returned value of step 3 is your constant
This might not be perfect as you still have to maintain your dictionary but you can avoid long if...else statements.
As a alternative have a look on Decisions Tables in Appian https://docs.appian.com/suite/help/21.1/Appian_Decisions.html
I have this armor table, that has three fields to identify individual designs: make, model and version.
I have to implement a search feature for our software, that lets a user search armors according to various criteria, among which their design.
Now, the users' idea of a design is a single string that contains make, model and version concatenated, so the entry is that single string. Let's say they want to look up the specifications for make FH, model TT, version 27, they'll think of (and type) "FHTT27".
We use an IQueryOver object, upon which we add successive conditions according to the criteria. For the design, our code is
z_quoQuery = z_quoQuery.And(armor => armor.make + armor.model + armor.version == z_strDesign);
Which raises an InvalidOperationException, "variable 'armor' of type 'IArmor' referenced from scope '', but it is not defined".
This is described as a bug here: https://github.com/mbdavid/LiteDB/issues/637
After a lot of trial and error, it seems that syntaxs that don't use the armor variable first raise that exception.
Obviously, I have to go another route at least for now, but after searching for some time I can't seem to find how. I thought of using something like
z_quoQuery = z_quoQuery.And(armor => armor.make == z_strDesign.SubString(0, 2).
And(armor => armor.model == z_strDesign.SubString(2, 2).
And(armor => armor.version == z_strDesign.SubString(4, 2);
Unfortunately, the fields are liable to have variable lengths. For instance, another set of values for make, model, and version might be, respectively, "NGI", "928", and "RX", that the code above would parse wrong. So I can't bypass the difficulty that way. Nor can I use a RegEx.
Neither can I make up a property in my Armor class that would concatenate all three properties, since it cannot be converted to SQL by NHibernate.
Has someone an idea of how to do it?
Maybe I should use an explicit SQL condition here, but how would it mix with other conditions?
It seems you can use Projections.Concat to solve your issue:
z_quoQuery = z_quoQuery.And(armor => Projections.Concat(armor.make, armor.model, armor.version) == z_strDesign);
Is there any Function module that can generate ABAP code.
For eg: FM takes tables name and join conditions as input and generate ABAP code corresponding to that.
Thanks
You should consider using SAPQuery. SAP documentation here: https://help.sap.com/saphelp_erp60_sp/helpdata/en/d2/cb3efb455611d189710000e8322d00/content.htm
1. Generic reports are possible.
Your problem is, that You will have to draw a strict frame of what is
generic and what not, this means, some stuff MUST be that generic, that
it will deal with WHATEVER You want to do before ( mostly the selection ) ,
during ( mostly manipulation ---> I would offer a badi for that ), and output.
This means, that there is at least the output-step, which can be valid for ALL
data resulting from the steps before.
Consider a generic ALV-table_output, there are a lot of examples in the repo.
If You want to be the stuff printed out simple as list, this might include
more work, like, how big is the structure, when Dou You wrap a line, and so on, consider using a flag which allows to toggle the type of output .
2. Generic reports are a transportable object.
This refers to point one. Define clear stages and limits. What does the report do, and what is it not able to do. Because, even if it is in customer's namespace, each modification still will be put into transport-layers. Therefore a strict definition of features/limits is necessary so that the amount of transports due to "oh, but we also need that"-statements will not become infinite.
2. Generic reports are strict.
What does that mean ? You might want to parse the passed data ( table names, join-binding, selection-parameter-values ) and throw exceptions, if not properly set. Much work. You should offer a badi for that. If You do not do this, expect a dump. let it dump. In the end the user of Your report-api should know ( by documentation perhaps) how to call it. If not, a dynamic SQL-dump will be the result.
3. Generic reports might benefit from badis/exits.
This is self explanaining, I think. Especially generic/dynamic selection/modification/displaying of data should be extendable in terms of
custom-modifications. When You inspect, what a f4-search-help exit works like, You will understand, what I mean.
4. Generic coding is hard to debug, mostly a blackbox.
Self explaining, in the code-section below I can mark some of those sections.
5. Generic coding has some best prectice examples in the repo.
Do not reinvent the wheel. Check, how the se16n works by debugging it,
check how se11 works by debugging it. Check, what the SQL-Query-builder
looks like in the debugger. You will get the idea very soon,
and the copy-paste should be the most simple part of Your work.
6. That are the basic parts of what You might use.
Where clause determination and setting the params.
data lt_range type rsds_trange.
data ls_range_f type rsds_frange.
data lt_where type rsds_twhere.
data ls_where like line of lt_where.
ls_range_f = value #( sign = _sign
option = _option
low = _low
high = _high ).
.
.
.
append ls_frange to lt_range.
.
.
.
call function 'FREE_SELECTIONS_RANGE_2_WHERE'
exporting
field_ranges = lt_range
importing
where_clauses = lt_where.
You have the parameter, let us create the select-result-table.
data(lt_key) = value abap_keydescr_tab( for line in _joinfields)
( name = fieldname ) ).
data(lo_structdescr) = cast cl_abap_structdescr( cl_abap_structdescr=>describe_by_name( _struct_name ) ).
data(lo_tabledescr) = cl_abap_tabledescr=>create( line_type = lo_structdescr p_key = lt_key ).
create data ro_data type handle lo_tabledescr.
.
.
.
select (sel_st)
from (sel_bind)
into corresponding fields of table t_data
where (dyn_where).
Then assign the seelct-table-result-reference to the generic table of this select.
Do You need more hints ?
Yes, such possibility exists, but not by means of function modules. INSERT REPORT statement allows generating report by populating its code from internal text table:
INSERT REPORT prog FROM itab
[MAXIMUM WIDTH INTO wid]
{ [KEEPING DIRECTORY ENTRY]
| { [PROGRAM TYPE pt]
[FIXED-POINT ARITHMETIC fp]
[UNICODE ENABLING uc] }
| [DIRECTORY ENTRY dir] }.
I have a model:
class List:
data = ...
previous = models.ForeignKey('List', related_name='r1')
obj = models.ForeignKey('Obj', related_name='nodes')
This is one direction list containing reference to some obj of Obj class. I can reverse relation and get some list's all elements refering to obj by:
obj.nodes
But how Can I get the very last node? Without using raw sql, genering as little SQL queries by django as can.
obj.nodes is a RelatedManager, not a list. As with any manager, you can get the last queried element by
obj.nodes.all().reverse()[0]
This makes sense anyway only if there is any default order defined on the Node's Meta class, because otherwise the semantic of 'reverse' don't make any sense. If you don't have any specified order, set it explicitly:
obj.nodes.order_by('-pk')[0]
len(obj.nodes)-1
should give you the index of the last element (counting from 0) of your list
so something like
obj.nodes[len(obj.nodes)-1]
should give the last element of the list
i'm not sure it's good for your case, just give it a try :)
I see this question is quite old, but in newer versions of Django there are first() and last() methods on querysets now.
Well, you just can use [-1] index and it will return last element from the list. Maybe this question are close to yours:
Getting the last element of a list in Python
for further reading, Django does not support negative indexing and using something like
obj.nodes.all()[-1]
will raise an error.
in newer versions of Django you can use last() function on queryset to get the last item of your list.
obj.nodes.last()
another approach is to use len() function to get the index of last item of a list
obj.nodes[len(obj.nodes)-1]