If I have a
type Status
= Open Time
| Closed
type alias Time = { open : Int , closed : Int , message : Maybe String }
data : List Status
and I want to update a Status record on data
and I have a function that gets me the record I want to update, how do I then update a union type, where record is a Status?
As mentioned, you cannot update a Union type since types are not mutable like in OOP. Instead, you have to replace it with a shiny brand new one and put it in its container (most often a Record).
-- the container for the Status type
type alias Store = {status: Status, name: String}
-- type that cannot be modified, only replaced with new instances
type Status
= Open Time
| Closed
type alias Time = { open : Int, closed : Int, message : Maybe String }
starbucks = openStore {name: "StarBucks", status: Closed}
-- close down the store to prevent kids from feeling cool
closeStore store =
{store | status = Closed}
-- open a store to help a multinational extract value from your country
openStore store =
{store | status = Open {open: 9, closed: 18, message: Just "Get your sugar injection here!"}}
Related
Here I have several functions that all just set a single field on a model record.
In a more dynamic language, I'd just have a single setter function and pass it the name of the field (as a string) and the value that I want to set on the model object.
Is there a way to pass the name of the field in Elm?
What's the Elm way of doing something like this?
type alias Patient =
{ id : String
, name : String
, dateOfBirth : String
, sex : String
... other fields
}
setPatientName : Patient -> String -> Patient
setPatientName patient value =
{ patient | name = value }
setPatientDateOfBirth : Patient -> String -> Patient
setPatientDateOfBirth patient value =
{ patient | dateOfBirth = value }
setPatientSex : Patient -> String -> Patient
setPatientSex patient value =
{ patient | sex = value }
... many others
-- idx is the index of the patient in the model (which is an array of patients)
-- UpdateCell is a variant of my Msg type, like this: UpdateCell Int (Patient -> String -> Patient) String
onInputHandler : Int -> (Patient -> String -> Patient) -> String -> Msg
onInputHandler idx setter inputText =
UpdateCell idx setter inputText
-- idx is the index of the patient in the model (which is an array of patients)
createTableRow : Int -> Patient -> Html Msg
createTableRow idx patient =
...
, input [ type_ "text", onInput (onInputHandler idx setPatientName), value patient.name ] []
, input [ type_ "text", onInput (onInputHandler idx setPatientDateOfBirth), value patient.dateOfBirth ] []
...
I'm currently using each of these functions as an event handler for input elements. So I need a function that I can use for handling the input event. Ideally, I'd define just a single function and use that single one for all the input elements and pass it the field I want to update on the patient record.
The short answer is "no". But this seems a bit like an XY problem. It's not clear what benefit you are trying to achieve since the full application of such a function would be longer than the equivalent record update expression:
setField "name" patient value
-- vs
{ patient | name = value }
and as a partially applied function is only slightly shorter than the equivalent anonymous function with shortened argument names:
setField "name"
-- vs
\r x -> { r | name = x }
Although the latter is significantly noisier with all the symbols.
There is also a short-hand function for getting a record field:
.name
-- vs
\r -> r.name
So there is some precedent for having a dedicated syntax for setter functions too, but unfortunately there is not. Likely because it would complicate the language, and the syntax in particular, for relatively little benefit. I'm therefore curious about what you're actually trying to accomplish.
Edit after question update:
Putting functions in the Msg is a very bad idea because it goes against the Elm Architecture. It makes the state transition opaque and won't work very well with the debugger. When something goes wrong you can still see the state before and after, but you'll have trouble understanding what happened, and why it happened, because that information is encoded in an opaque function which probably isn't the one it should be.
You'll also have trouble factoring your logic. If you need something to happen only when a certain field updates, you might have to put the logic in the view, or special-case that field by putting the logic for that in update while the rest is in view, for example. Either way, you're on the path to a messy code base.
You should generally use names for messages that describe what happened, not what to do, because that tends to lead to an imperative mindset. Instead of UpdateCell you could call it InputChanged, for example. Then instead of the function you should have an identifier for the field. Ideally a custom type, like InputChanged Name, but even a string will work, though it will be much easier to miss a typo.
So instead of setter functions for each field you'll just case match the message and set the field in the update function:
InputChanged Name value ->
{ patient | name = value }
-- vs
setPatientName : Patient -> String -> Patient
setPatientName patient value =
{ patient | name = value }
Then if you need to clear the sex when the name changes, for example (because reasons...), you can simply do:
InputChanged Name value ->
{ patient | name = value, sex = "" }
The Elm Architecture is good because it makes changes easy and safe, not because it's concise and free of boiler-plate. Good Elm code often has a lot of copy-and-paste, but that's not always bad.
I'm trying to use the class /ui5/cl_json_parser for parsing a JSON string.
The following code snippet reproduces the problem:
REPORT ztest_json_parse.
DATA: input TYPE string,
output TYPE string,
json_parser TYPE REF TO /ui5/cl_json_parser.
input = '{"address":[{"street":"Road","number":"545"},{"street":"Avenue","number":"15"}]}'.
CREATE OBJECT json_parser.
json_parser->parse( input ).
json_parser->print( ).
output = json_parser->value( path = '/address/1/street' ).
WRITE output.
The print method shows the correct parsed JSON string, but the output variable is always empty.
I have traced the code down to the method VALUE of the class /UI5/CL_JSON_PARSER, at line 15, which contains:
read table m_entries into l_entry with table key parent = l_parent name = l_name.
In the debugger, I can see that l_parent = '/address/1' and l_name = 'street', and that the internal table m_entries contains a record with parent = '/address/1' and name = 'street'. Nevertheless the READ statement always returns sy-subrc = 4 and does not find anything.
Can anyone help?
First: Do not use /ui5/cl_json_parser class, it is intended for internal use ONLY and has no reliable documentation
Secondly, here is the sample how you can fetch street value from the first element of your JSON:
DATA(o_json) = cl_abap_codepage=>convert_to( '{"address":[{"street":"Road","number":"545"},{"street":"Avenue","number":"15"}]' ).
DATA(o_reader) = cl_sxml_string_reader=>create( o_json ).
TRY.
DATA(o_node) = o_reader->read_next_node( ).
WHILE o_node IS BOUND.
DATA(op) = CAST if_sxml_open_element( o_node ).
LOOP AT op->get_attributes( ) ASSIGNING FIELD-SYMBOL(<a>).
DATA(attr) = <a>->get_value( ).
ENDLOOP.
IF attr <> 'street'.
o_node = o_reader->read_next_node( ).
ELSE.
DATA(val) = CAST if_sxml_value_node( o_reader->read_next_node( ) ).
WRITE: '/address/1/street =>', val->get_value( ).
EXIT.
ENDIF.
ENDWHILE.
CATCH cx_root INTO DATA(e_txt).
ENDTRY.
As far as I know, there is no class in ABAP that allows fetching single JSON attributes like XPath.
Certainly agree with Suncatcher on avoid UI5 Json parser.
If you dont control/know the structure of the source data, Suncatchers answer is good.
However,
if you know the basic structure of the source JSON and you must, if you plan to access the first address row, fieldname street .
AND you can have the source provided using uppercase variable names then you can use the so called identity transformation.
types: begin of ty_addr,
street type string,
number type string,
end of ty_addr.
types ty_addr_t type STANDARD TABLE OF ty_addr.
DATA: input TYPE string,
ls_addr TYPE ty_addr,
lt_addr type ty_addr_t.
input = '{"ADDRESS":[{"STREET":"Road","NUMBER":"545"},{"STREET":"Avenue","NUMBER":"15"}]}'.
CALL TRANSFORMATION id SOURCE XML input
RESULT address = lt_addr.
read table lt_addr index 1 into ls_addr.
WRITE ls_addr-street.
We got into difficulties in maintaining the ITXEX field (Long text indication) of an Infotype record.
Say we got an existing record in an Infotype database table with a long text filled (ITXEX field value in that record is set to 'X').
Some process updates the record through HR_CONTROL_INFTY_OPERATION like this:
CALL FUNCTION 'HR_CONTROL_INFTY_OPERATION'
EXPORTING
infty = '0081'
number = '12345678'
subtype = '01'
validityend = '31.12.9999'
validitybegin = '19.05.2019'
record = ls_0081 " ( ITXEX = 'X' )
operation = 'MOD'
tclas = 'A'
nocommit = abap_true
IMPORTING
return = ls_return.
This call does update the record but clearing it's ITXEX field.
It's important to say that making the same action through PA30 does update the record and maintain ITXEX field as it was.
The described problem seems similar to that question. Trying the solutions given there didn't solve the problem.
Why the two approaches (PA30 and function module) don't work the same? How to fix this?
First of all, FM parameters you use are incorrect. How do you want the infotype to be updated if you set nocommit = TRUE?
Also, you are missing the correct sequence which must be used for the update procedure:
Lock the Employee
Read the infotype
Update the infotype
Unlock the Employee
The correct snippet for your task would be
DATA: ls_return TYPE bapireturn1.
DATA: l_infty_tab TYPE TABLE OF p0002.
CALL FUNCTION 'HR_READ_INFOTYPE'
EXPORTING
pernr = '00000302'
infty = '0002'
TABLES
infty_tab = l_infty_tab.
READ TABLE l_infty_tab ASSIGNING FIELD-SYMBOL(<infotype>) INDEX 1.
<infotype>-midnm = 'Shicklgruber'. " updating the field of infotype
CALL FUNCTION 'ENQUEUE_EPPRELE'
EXPORTING
pernr = '00000302'
infty = '0002'.
CALL FUNCTION 'HR_CONTROL_INFTY_OPERATION'
EXPORTING
infty = <infotype>-infty
number = <infotype>-pernr
subtype = <infotype>-subty
validityend = <infotype>-endda
validitybegin = <infotype>-begda
record = <infotype>
operation = 'MOD'
tclas = 'A'
IMPORTING
return = ls_return.
CALL FUNCTION 'DEQUEUE_EPPRELE'
EXPORTING
pernr = '00000302'
infty = '0002'.
This way itxex field is treated correctly and if existed on that record, will remain intact. However, this method will not work for updating the long text itself, for that you must use object-oriented way, methods of class CL_HRPA_INFOTYPE_CONTAINER.
I want to use a keyset of a Map as a list parameter in a SQL query:
query = "select contentid from content where spaceid = :spaceid and title in (:title)"
sql.eachRow(query, [spaceid: 1234, title: map.keySet().join(',')]) {
rs ->
println rs.contentid
}
I can use single values but no Sets or Lists.
This is what I've tried so far:
map.keySet().join(',')
map.keySet().toListString()
map.keySet().toList()
map.keySet().toString()
The map uses Strings as key
Map<String, String> map = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
Also, I don't get an error. I just get nothing printed like have an empty result set.
You appoach will not give the expected result.
Logically you are using a predicate such as
title = 'value1,value2,value3'
This is the reason why you get no exception but also no data.
Quick search gives a little evidence, that a mapping of a collections to IN list is possible in Groovy SQL.
Please check here and here
So very probably you'll have to define the IN list in a proper length and assign the values from your array.
title in (:key1, :key2, :key3)
Anyway something like this works fine:
Data
create table content as
select 1 contentid, 1 spaceid, 'AAA' title from dual union all
select 2 contentid, 1 spaceid, 'BBB' title from dual union all
select 3 contentid, 2 spaceid, 'AAA' title from dual;
Groovy Script
map['key1'] = 'AAA'
map['key2'] = 'BBB'
query = "select contentid from content where spaceid = :spaceid and title in (${map.keySet().collect{":$it"}.join(',')})"
println query
map['spaceid'] = 1
sql.eachRow(query, map) {
rs ->
println rs.contentid
}
Result
select contentid from content where spaceid = :spaceid and title in (:key1,:key2)
1
2
The key step is to dynamicall prepare the IN list with proper names of the bind variable using the experssion map.keySet().collect{":$it"}.join(',')
Note
You may also want to check the size if the map and handle the case where it is greater than 1000, which is an Oracle limitation of a single IN list.
It has worked for me with a little adaptation, I've added the map as a second argument.
def sql = Sql.newInstance("jdbc:mysql://localhost/databaseName", "userid", "pass")
Map<String,Long> mapProduitEnDelta = new HashMap<>()
mapProduitEnDelta['key1'] = 1
mapProduitEnDelta['key2'] = 2
mapProduitEnDelta['key3'] = 3
produits : sql.rows("""select id, reference from Produit where id IN (${mapProduitEnDelta.keySet().collect{":$it"}.join(',')})""",mapProduitEnDelta),
Display the 3 products (colums + values from the produit table) of id 1, 2, 3
Is there is any way to import the error logs from event viewer to SQL table and schedule a job on daily basis. I would like to use a powershell script or SSIS package.
First you could easily find answer on the web, but as I wanted to try this too, here is tested result.
Create table
You can make something like this:
CREATE TABLE WinLogs (
EntryType VARCHAR(255),
[Source] VARCHAR(255),
[Message] VARCHAR(4000),
TimeGenerated datetime
)
Create package
Add Data Flow task to package;
Inside package add Script Component, where you should add 4 output columns (arrows show what to change):
EntryType (string 255)
Source (string 255)
Message (string 4000)
TimeGenerated (database timestamp)
Add below code to this component:
public override void CreateNewOutputRows()
{
// Get all events from the Application(/System/Security) log from the local server (.)
EventLog myEvenLog = new EventLog("Application", ".");
// Create variable to store the entry
EventLogEntry myEntry;
// Loop trough all entries (oldest first)
for (int i = 0; i < myEvenLog.Entries.Count; i++)
{
// Get single entry
myEntry = myEvenLog.Entries[i];
// Add new records
this.Output0Buffer.AddRow();
// Fill columns
this.Output0Buffer.EntryType = myEntry.EntryType.ToString();
this.Output0Buffer.Source = myEntry.Source;
this.Output0Buffer.TimeGenerated = myEntry.TimeGenerated;
// Take a max of 4000 chars
this.Output0Buffer.Message = myEntry.Message.Substring(0, (myEntry.Message.Length > 4000 ? 3999 : myEntry.Message.Length - 1));
}
}
And the last step is to add SQL Server Destination component (also can be OLE DB Destination)
Create Connection manager and select table where to insert data (look if mapping is correct).
Run this package and you will see that data are inserted.
The source is from this example Eventlog as a source