Dynamic variable NAME creation in Flutter - flutter

I need to dynamically create a List variable depending on the situation.
I have a List of strings. These were created dynamically.
List Categories = [name: 'String 1', name: 'String 2', name: 'String 3']
I need to create a List variable dynamically that can hold EACH string. Don't ask me why, but trust me.
I need something like this:
for(int i = 0 ; i < Categories.length ; i ++)
{
// logic to create a variable of List type and even name it according to the value it is holding:
List String1Var = Categories.[i].name
// or even better :
List $Categories.[i].name = ....
}
so String1Var needs to be named as String1Var - i.e. the name itself has to be dynamic, and the contents too.
Is this possible in flutter?? Or have Google still yet to advance their language so it works for people like me?
Is that the right syntax? How do I dynamically create a variable name?

What you want can be done with the help of Map.
Instead of creating separate variables we are generating dynamic keys and storing the values in it, As Dart has no concept for dynamic variables.
Code:
final Map myCategoryDynamic = {};
for(int i = 0 ; i < Categories.length ; i ++)
{
// logic to create a variable of List type and even name it according to the value it is holding:
myCategoryDynamic['String'+i.toString()+'Var'] = Categories.[i].name;
}
So when we need to check the values - we can check by - myCategoryDynamic[String1Var] myCategoryDynamic[String2Var] and so on...

Related

How to loop through two lists at the same time - Flutter

I'm trying to loop through two lists at the same time
For example
List A = ['Chapter 1','Chapter 2','Chapter 3'];
List B = ['Paragraph 1','Paragraph 2','Paragraph 3'];
for(var chapter in A) // This would itreate through only first list (A), How can I iterate through both list
children: [
Text(chapter);
Text(paragraph);
]
I need to iterate through both lists at the same time in "for" loop.
Here is the code:
List A = ['Chapter 1','Chapter 2','Chapter 3'];
List B = ['Paragraph 1','Paragraph 2','Paragraph 3'];
for (int i = 0; i < A.length; i++) {
print ("${A[i]}");
print ("${B[i]}");
}
Let me know if this does not help.
final c = zip([a, b]).map((item) => Foo(item[0], item[1])).toList();
I went along with Randal Schwartz's note about IterableZip. Note that I was not able to find any zip mentioned by Gbenga, and also note that package:collection/iterable_zip.dart is deprecated, you'd need to import simply the collection.dart, like so:
import 'package:collection/collection.dart';
final A = ['Chapter 1','Chapter 2','Chapter 3'];
final B = ['Paragraph 1','Paragraph 2','Paragraph 3'];
for (final pairs in IterableZip([A, B])) {
print(pairs[0]);
print(pairs[1]);
}
Some more notes:
final A and final B variables will be typed List<String> lists, I disadvise dynamic List A.
I have not specified template type for IterableZip, but in some cases (in a complex case where I used it) you may need to explicitly type it like IterableZip<String>, so in the loop you can more conveniently access the members. In this simple case the compiler/interpreter can infer the type easily.
Some other answers in other StackOverflow issues mention quiver, but unless you need it for some other features you don't have to add another extra package dependency to your project. The standard collection package has this IterableZip

ag-Grid set filter and sort model without triggering event

I am updating sort & filter models via api:
this.gridApi.setFilterModel(filterModels);
this.gridApi.setSortModel(sortModels);
The problem with this is I have a server request bound to the change even of both sort & filter so when user changes then the data is updated. This means when I change model on code like restoring a state or resetting the filters it causes multiple requests.
Is there a way to update the filter/sort model without triggering the event?
I see there is a ColumnEventType parameter but couldn't see how it works. Can I specify some variable that I can look for inside my event handlers to get them to ignore calls that are not generated from user?
I am trying to manage URL state so when url query params change my code sets the models in the grids but this ends up causing the page to reload multiple times because the onFilter and onSort events get called when the model is set and there is no way I can conceive to prevent this.
At the time, you are going to have to manage this yourself, ie, just before you call the setModel, somehow flag this in a shared part of your app (maybe a global variable)
Then when you react to these events, check the estate of this, to guess where it came from.
Note that at the moment, we have added source to the column events, but they are not yet for the model events, we are planning to add them though, but we have no ETA
Hope this helps
I had to solve similar issue. I found solution which working for my kind of situation. Maybe this help someone.
for (let j = 0; j < orders.length; j++) {
const sortModelEntry = orders[j];
if (typeof sortModelEntry.property === 'string') {
const column: Column = this.gridColumnApi.getColumn(sortModelEntry.property);
if (column && ! column.getColDef().suppressSorting) {
column.setSort(sortModelEntry.direction.toLowerCase());
column.setSortedAt(j);
}
}
this.gridApi.refreshHeader();
Where orders is array of key-value object where key is name of column and value is sorting directive (asc/desc).
Set filter without refresh was complicated
for (let j = 0; j < filters.length; j++) {
const filterModelEntry = filters[j];
if (typeof filterModelEntry.property === 'string') {
const column: Column = this.gridColumnApi.getColumn(filterModelEntry.property);
if (column && ! column.getColDef().suppressFilter) {
const filter: any = this.gridApi.getFilterApi(filterModelEntry.property);
filter['filter'] = filterModelEntry.command;
filter['defaultFilter'] = filterModelEntry.command;
filter['eTypeSelector'].value = filterModelEntry.command;
filter['filterValue'] = filterModelEntry.value;
filter['filterText'] = filterModelEntry.value;
filter['eFilterTextField'].value = filterModelEntry.value;
column.setFilterActive(true);
}
}
}
Attributes in filter:
property - name of column
command - filter action (contains, equals, ...)
value - value used in filter
For anyone else looking for a solution to this issue in Nov 2020, tapping into onFilterModified() might help. This gets called before onFilterChanged() so setting a value here (eg. hasUserManuallyChangedTheFilters = false, etc.) and checking the same in the filter changed event is a possible workaround. Although, I haven't found anything similar for onSortChanged() event, one that gets called before the sorting is applied to the grid.
I am not sure any clean way to achieve this but I noticed that FilterChangedEvent has "afterFloatingFilter = false" only if filterModel was updated from ui.
my workaround is as below
onFilterChanged = event:FilterChangedEvent) => {
if(event.afterFloatingFilter === undefined) return;
console.log("SaveFilterModel")
}

as3 - loop over all text fields?

I have a form in as3 flash with textfields and radio buttons with their "instance name" all set consecutively such as:
field_1
field_2
field_3
...etc
Is there an easy way in AS3 code to loop over all those fields and get their values in an array? Ideally I'd like a simply loop to get the values (so I can add in a simple popup if a value is missing) and then with the filled array simply post it using URLRequest.
Thanks!
If you want a way that's a little less work and more maintainable (if the amount of text can change in the future or you need to reuse the code on other forms or don't want to bother with instance names), then you could do something like the code below.
Keep in mind this assumes all your text fields are children of the same parent and is in the scope of that parent (so on a frame in the timeline that holds all your text fields)
function validateTextFields(){
var tmpTf:TextField;
var i:int = numChildren;
while(i--){ //iterate through all the display objects on this timeline
tmpTf = getChildAt(i) as TextField;
if(tmpTf){
//now that you have the textfield, you can check for an appropriate value, or send the value to a server, or store it in an array etc.
//check if the value is blank, if so set the background to red
if(tmpTf.text == ""){
tmpTf.background = true;
tmpTf.backgroundColor = 0xFF0000;
}else{
tmpTf.background = false;
}
}
}
}
It sounds like you want to use a for statement. I've also used a multi-dimensional array to store the instance names, and the text that they contain. I like to use the variable _path to define the scope of my code.
var _path = this;
var text_ar:Array = new Array(['instance_1',''],['instance_2',''],['instance_3','']); //instance name, instance text.
for(var i=0; i<ar.length; i++)
{
text_ar[i][1] = _path[text_ar[i][0]].text
}
trace( text_ar[1][1] ); //Traces the text that's entered in instance_1.

jqgrid edittype select load value from data

I am using jqgrid in my new project.
In a specific case I need to use a select element in the grid. No problem.
I define the colModel and the column for example like (from wiki)
colModel : [
...
{name:'myname', edittype:'select', editoptions:{value:{1:'One',2:'Two'}} },
...
]
But now when I load my data I would prefer the column "myname" to contain the value 1.
This won't work for me instead it has to contain the value "One".
The problem with this is that the text-part of the select element is in my case localized in the business layer where the colModel is dynamically generated. Also the datatype for the entity which generates the data via EF 4 may not be a string. Then I have to find the correct localized text and manipulate the data result so that the column "myname" does not containt an integer which is typically the case but a string instead with the localized text.
There is no option you can use so that when the data contains the value which match an option in the select list then the grid finds that option and presents the text.
Now the grid presents the value as a text and first when I click edit it finds the matching option and presents the text. When I undo the edit it returns to present the value again.
I started to think of a solution and this is what I came up with. Please if you know a better solution or if you know there is a built in option don't hesitate to answer.
Otherwise here is what I did:
loadComplete: function (data) {
var colModel = grid.getGridParam('colModel');
$.each(colModel, function (index, col) {
if (col.edittype === 'select') {
$.each(grid.getDataIDs(), function (index, id) {
var row = grid.getRowData(id);
var value = row[col.name];
var editoptions = col.editoptions.value;
var startText = editoptions.indexOf(value + ':') + (value + ':').length;
var endText = editoptions.indexOf(';', startText);
if (endText === -1) { endText = editoptions.length; }
var text = editoptions.substring(startText, endText);
row[col.name] = text;
grid.setRowData(id, row);
});
}
});
}
It works and I will leave it like this if nobody comes up with a better way.
You should just include additional formatter:'select' option in the definition of the column. See the documentation for more details.

Dijit/Dojo Inline - Filtering Select - DataStore

I am using an inline filteringselect with datastore, as follows:
I am using ABBR as the identifier and NAME as the value.
The filtering selects and works correctly, but I have two issues.
Firstly, how do I retrieve the ABBR for the selected option NAME?
I have tried various things, including .innerHTML but that only retrieves the selected item name, not the identifier.
Secondly, when using the datastore option, how can I choose the default selected item, for example if it was a scale of 1 to 10 and I wanted 5 as the default selection, how can I do this?
Any ideas and advice would be greatly appreciated.
Mank thanks
dojo.addOnLoad(function() {
// inline store
str = new dojo.data.ItemFileReadStore({data: storeData10})
var itmes;
// for storing the store's items
str.fetch({
onComplete:function(itms){
itmes= itms;
console.log(itms)
}
})
dijit.byId("cmbx1").store = str
dojo.connect(dijit.byId("cmbx1"), 'onChange',function(){
//console.log(arguments);
//get the value u c in screen
var whatvseeinselect = dijit.byId("cmbx1").focusNode.value;
dojo.forEach(itmes, function(itm){
//compare the value u c in screen with store itms. once matched take that item and get the name attr or other attr if u require..
if(whatvseeinselect == str.getValue(itm,"name")){
console.log(str.getValue(itm,"name"));
}
})
})
});
I'm not sure whether this is the correct way.
Hope this helps