Is it possible to bind control visibility to the content? (XAML) - xaml

I created a result view for a class, calculating some math-stuff. According to the values, set by the user, there are some of the results returning 0 or "". So some of the Controls bound to this empty properties are also empty. Thats some kind of ugly, because calculating with these Values will never contain such a result. So I don't want to show this control.
Is it possible, not to show this control if the property it is bound to is empty?
Greetings from Germany

Bind Value to element Visibility property with help of Converter that will provide your logic.

Related

Why did I have to manually set the .value from the .text on losing focus in an unbound textbox

I have an unbound textbox to accept the delete older than: number of days. It is in the report header. I set it to 30 days but I want the user to be able to change it. I was banging my head trying to figure out why entering 40 was not being accepted and it reverted back to 30 every time. I finally decided on using the lost_focus event to set .value to .text. That worked.
Further research showed that when the textbox get's focus text and value are both the same, 30 in my case. Changing the number in the text box to 40 shows the values of text at 40 and value at 30. Unless I specifically set Value to the value of text Access changes text to the value of value. This is different behavior than other places in Access such as forms.
Can anyone tell me why this might be? I can't find any setting that might do this. Is it because it's in a report header? what is the difference between this and every other text box I've ever used?
From a "best practices" viewpoint, Access Reports are not intended to be used interactively despite the ability to manipulate some unbound controls. Although workarounds can be implemented that function sufficiently well, such solutions are often incomplete and buggy and function differently depending on the active view: Report View vs. Print Preview. Appropriate design patterns include using Access Forms for specifying report options which then open the Report in a static configuration.
This may not satisfy the question "Why?" if seeking a deeper answer as to why Microsoft implemented inconsistent binding behavior in Access, or why they allowed interactive controls in reports at all if they don't behave the same way as in forms. But Access has plenty of other quirky behaviors that have no known/published explanation.
Regarding the priority of the Value property updating the Text property (and not vice versa): Value is the key field because it contains the actual data for the control (bound or unbound). Although it is natural to have a single control for both display and input (uh, that's how almost all controls work), the processes of displaying data and parsing user input are two distinct functions. The visual representation returned by the Text property can be manipulated using the various formatting properties, and technically could display an incomplete representation of the underlying Value data. If there are any conflicts between the stored Value property and the Text property, it is natural that the existing Value property has precedent.
My guess is that the automatic binding behavior was "relaxed" for reports to allow more flexible custom reporting output. First consider an Access Form in Datasheet view: An unbound Form control shows the same value for all records. Even if the control is edited while on a particular row, the updated value is displayed for all rows. The same control object is essentially repainted for each row and there is no concept of individual instances of the control that can hold different values. Bound controls have built-in code that repaint the control with data from the particular row, but there are still not multiple instances each "holding" the individual values. The visual output differs from an intuitive object-oriented paradigm where our minds what to assign each visual row its own in-memory instance of the controls--it just doesn't work like that in Access.
Unlike the Form behavior just described, the Report's Print Preview (and actual printed output) allows unbound controls to display different data per row using the Detail_Format() event. Within the Detail_Format() event, one can set the Value property of a control at which time the Text property is automatically updated according to various formatting properties. This update Text is then output for the current row. Perhaps (just guessing) that this behavior would not function properly if the Text property updated the value property. I suspect it would cause recursive events during report generation. Because reports are not meant to be interactive, relevant text-input parsing code was "disconnected" so that it doesn't behave like on a form.
All that explanation doesn't make Access any less frustrating nor remove its limitations, but at least learn to adapt and design things in the "Access-esque" way rather than fighting it.
your best bet is to design a form with the unbound combo boxes and have your data displayed in a subreport. I like to design my reports so that when values are updated the query for the recordsource of the report is generated doing this requires 2 queries to exist, one with all data possible and a filtered one as subreport recordsource. This will control the data for printing and also allow users to close or navigate away from the report and return to the data later.
Private Sub ComboBox1_AfterUpdate()
Dim Query1 as Object
Dim Temp_Name as Variant
Temp_Name = SubReport.SourceObject
SubReport.SourceObject = Empty
Set Query1 = Me.Form.Application.DBEngine.Workspaces(0).Databases(0).QueryDefs ("SubReport_Query")
Query1.SQL = "Select * Unfiltered_Query WHERE Field1 <= " ComboBox1 & ";"
SubReport.SourceObject = Temp_Name
End Sub

How to bind multiple property in xaml for label control in Xamarin

I have two property TotalWeightInGrams and TotalWeightInKiloGrams, i want to bind in label control as following output
string format="{0} ({1} Kgs)"
Easiest way would be to make a new property that returns the string you want and bind to that. This way you don't need to do anything more complicated and can change the formatting in code if needed.

BIRT result set values in specific cells

My query returns location_cd(string) and item_count(int). I only need certain rows from the result however and I need them to display in specific places in my layout so I don't think the table solution is going to work. Can I determine where I place the value for a particular row of the result set?
I am using a grid to display values for a number of fields. I cannot seem to be able to get the values from the results to show. The grid is bound to the result set. I even tried binding the cells to the result set but that didn't work either.
I checked in the query editor and there is a result set shown in the Preview so I know the query works. The complete and correct result set shows if I put a table on the page.
I tried inserting a Dynamic Text or Data object in a cell and used the expression:
dataSetRow["location_cd"]=="3SD"?dataSetRow["item_count"]:""
This returns a blank and does not seem to evaluate. I tested it with :
dataSetRow["location_cd"]=="3SD"?dataSetRow["item_count"]:"BLANK"
and got 'BLANK' to appear in that cell.
dataSetRow["location_cd"] and dataSetRow["item_count"] will display the location_cd and item_count from the first row of the result set. row.outer[] did the same thing. Obviously I am just hacking at this report at this point.
A co-worker suggested that she uses a JAVA if-statement in places like this but I could not get that to work either.
Any ideas or suggestions that will get me on the right road??
Thanks
An elegant option would be to use a HashMap storing the result of the dataset.
Declare a report variable named "values", with a new hashmap as default value (see image below)
Fill values in the onFetch script of the dataset: vars["values"].put(row["location_cd"],row["item_count"]);
Insert new data elements at any place of the report with expressions such: vars["values"].get("myFavoriteLocationCD");
Though it is important to note the dataset should be triggered by the report before these data elements.
The particular row you want to display you specify in a "Text" field inside your grid. Just drag and drop a "Text" field inside your grid. If you bound the fields you want to display to your grid, the "Text" field inside the grid inherits the bindings of its parent (the grid), so you can access the bindings automatically in the "Text" field.
You could try following steps, maybe that works.
Don't use "Dynamic Text" field, instead use a regular "Text" field
Ensure the fields of your query which you use, are bound to the grid (you sayed you already did)
Open the "Text" field
Change preselected pull-down entry "Auto" into "HTML"
Change preselected pull-down entry "Formatting" into "Dynamic Text"
Wrap your code in <value-of format="HTML"> your code goes here... </value-of>
Note: You should check in the "Expression Builder" of your "Text" field if you are able to access the fields you bound to the grid. If they are not available sth. went wrong with your binding. Avoid binding query records to cells this will drive you crazy.
If you want to display a list, ensure you didn't set a constant height in the row of your grid. Set the height to 100% than the row takes its height dynamically.
What about the idea to optimize your query, that only get the results you want are displayed, than you don’t need to filter them with java script? If you don’t need the filtered results in another place this would be the cleaner solution in my opinion.

How to show button cell (check box) title in table view, using bindings

I am trying a simple application where I have a mutable array of mutable dictionaries, such as -
NSMutableDictionary *sample6 = [[NSMutableDictionary alloc] initWithObjectsAndKeys:#"title6",#"title",[NSNumber numberWithBool:NO],#"state", nil];
In IB I created a table view with NSButtonCell (check box).
I was able to show checkboxes state (checked or unchecked), using following table column bindings:
Value - ArrayController.arrangedObjects.state
In this case it shows an array of checkboxes with title - "Check" as shown in below screen-shot:
Now my aim is to show checkboxes title using bindings, such that it
gets value from same mutable dictionary from which it is getting its
state.
I tried following binding for button cell but it did not work:
title -> ArrayController.selection.title
I also tried this binding for button cell :
title -> ArrayController.arrangedObjects.title
but it didn't work, it appeared like this after using above binding:
Can any one suggest me which controller key to use and if this is not the correct way to show titles then what is the correct way to do so?
Unfortunately you'll need to write a little code if you want to do it this way. When binding table column values to an array, the table column is handling taking the prototype data cell, setting its values, and "stamping" it in place for each row. The button cell's bindings aren't exposed "through" the table column, so a simple binding won't do it for you.
To Answer Your Question
So. Since only the value binding is exposed, the title must be set manually if you really want the checkbox's title to reflect the value (ie, you really want the checkbox to handle both the check state and displaying the title). To do this, you have to mix bindings with < NSTableDelegateProtocol > . Use the -tableView:willDisplayCell:forTableColumn:row: method to set the cell's -title property to that of the proper object in your array controller's -arrangedObjects array each time you're asked. Mixing bindings and data source / delegate methods is actually quite common for more than the most basic applications, so don't worry that you're doing something dirty. Note: you won't be able to support editing the title by doing this since it's a checkbox.
An Alternative Design
Personally, I'd avoid all that and just add a separate table column for the title. Bind the new column's value to the array controller's arrangedObjects.title and turn off the checkbox button cell's title so only the checkbox itself is displayed. That simplifies the whole thing greatly and allows editing the title.

Binding to NSMatrix for BOOL attributes

I have a simple core-data entity that has a Boolean attribute called subscribedToNewsletter. I have designed my UI to represent this field as a radio button group with Yes/No as the text values (and obviously YES/NO as the backing BOOL values).
I have always considered myself to have excellent google-fu, but for the life of me, I am unable to find any clear documentation on:
how to bind the selected value of the NSMatrix (or is it the cell?) back to a YES/NO value
how to bind the textual values (if indeed I do need to; I know there are only ever going to be two values - surely they can be hard-coded in Interface Builder, or not?)
Next up will be how to bind a radio group (with Male/Female text) to a String field called gender that has M and F as possible values - but I digress.
Any pointers would be very much appreciated. Thanks a lot.
Not sure if I got no answers because a) it is such a stupid question, or b) no-one in the world knows how. The latter doesn't strike me as likely, so I can only presume the first :)
Anyway just in case there others as stupid as me, I thought I'd give some feedback on how I managed to achieve it.
In Interface Builder, I created a NSMatrix with two radio button cells with "Yes" and "No" as the text for each respectively. In the Attributes Inspector (command-1), make sure the Tag field is set to 1 for the "Yes" button cell, and set to 0 for the "No" button cell. Then, in the Bindings Inspector (command-4) bind the SelectedTag field for the matrix to the Boolean property on your entity. Easy as pie.
I make no claims that this is the best way... just that it is effective.
I have found one solution for this part-
how to bind the selected value of the
NSMatrix (or is it the cell?) back to
a YES/NO value
Here is the link to the problem which I faced and its solution- NSMatrix simple binding question
Hope this helps !