Here's a snippet from my Studio Extension (a subclass of one of the more standard extensions) that you might use and adapt in yours. It deals with a few other things that /diffexport misses - the timestamp, and the order of project items (which will normally have newly-added items at the bottom, out of alphabetical order). Unfortunately, I haven't found a way to handle breakpoints - probably the easiest way to get rid of those would be applying an XSLT to the file after it's been exported, which is pretty bad.

Method OnAfterSave(InternalName As %String, Object As %RegisteredObject) As %Status
{
    Set tFileName = ..ExternalName(InternalName)
    If tFileName = "" {
        Quit $$$OK
    }
    
    Set tName = $Piece(InternalName,".",1,*-1)
    Set tExt = $ZConvert($Piece(InternalName,".",*),"U")
    
    // Special handling for projects to ensure that newly-added items don't show up at the bottom of the XML export.
    // This tends to cause meaningless diffs (at best) and conflicts (at worst)
    If (tExt = "PRJ") {
        Set tProject = ##class(%Studio.Project).%OpenId(tName,,.tSC)
        If $IsObject(tProject) {
            // Save the project for real (we'll be in %OnAfterSave for the project when this happens,
            // but %Studio.SourceControl.Interface protects against <FRAMESTACK> by moving %SourceControl
            // to tmp, so this should be perfectly fine).
            // If the project is not saved, the items will be in the wrong order.
            If tProject.%Save() {
                // Reload the project. We need to save first to be sure all ProjectItem changes are commited.
                // This will load them up freshly, in the normal order.
                Do tProject.%Reload()
            }
            // Clear a few properties, since /diffexport won't be respected.
            // This won't actually be saved, but these things shouldn't be in the export to disk.
            Set tProject.LastModified = ""
            Set tProject.Target = ""
            Set tProject.TargetType = ""
        }
    }
    Quit ##super(.InternalName,.Object)
}

If you're looking to add RegEx-based validation to a property, see this post.

If you're looking to do RegEx matching in a query... I don't think there's a built in function for this (!), but it's easy enough to do in a stored procedure:

ClassMethod MatchesRegEx(pText As %String, pRegEx As %String) As %Boolean [ SqlProc ]
{
    Quit $Match(pText,pRegEx)
}

See class documentation for Security.Applications.

Example:

Class DC.Demo.DeepSeeEnable
{

ClassMethod SetDSFlag(pApplicationName As %String, pValue As %Boolean = 1) As %Status
{
    Set tSC = $$$OK
    Try {
        New $Namespace
        Set $Namespace = "%SYS"
        
        Set tApplication = ##class(Security.Applications).%OpenId(pApplicationName,,.tSC)
        If $$$ISERR(tSC) {
            Quit
        }
        
        Set tApplication.DeepSeeEnabled = pValue
        Set tSC = tApplication.%Save()
    } Catch e {
        Set tSC = e.AsStatus()
    }
    Quit tSC
}

}

Use:

USER>s sc = ##class(DC.Demo.DeepSeeEnable).SetDSFlag("/csp/user",1)
 
USER>w sc
1

Hi Sebastian,

In the past, when I've tried to be creative and make <dataCombo> work more like a <select>, the better solution has been to just use a <select>, possibly customized a little bit to make it behave nicer with changing query parameter values. What's the reasoning for using a <dataCombo> rather than a <select> in your case?

Here's some custom component code that might serve as a basis for a full solution. The trick is setting editable="true", overriding findSelectedItem to select the best match to the input text, and calling findSelectedItem after changes, using the built-in timer for the sake of simplicity. Compare to a normal dataCombo for reference.

/// dataCombo subclass with limited support for responding to keyboard events
Class DC.Demo.ZEN.Component.dataCombo Extends %ZEN.Component.dataCombo [ System = 3 ]
{

///  This is the XML namespace used for library components.
Parameter NAMESPACE = "http://www.intersystems.com/zen/dc/demo";

/// Always editable, of course.
Property editable As %ZEN.Datatype.boolean [ InitialExpression = 1 ];

/// Onclick, show the dropdown.
Property onclick As %ZEN.Datatype.eventHandler [ InitialExpression = "zenThis.showDropdown();" ];

/// Find and select item within the dropdown that matches current control value.
/// This is called when the dropdown appears to make sure that the current
/// item is highlighted.
ClientMethod findSelectedItem(force, update, select) [ Language = javascript ]
{
    force = ('undefined'!=force)?force:false;
    update = ('undefined'!=update)?update:true;
    select = ('undefined'!=select)?select:false;
    var inputValue = this.findElement('input').value.toUpperCase();
    this.keyMode = true;
    if (force||this.isDropdownVisible) {
        var count = this.getOptionCount();
        var dVal = new Array();
        for (var idx = 0; idx < count; idx++) {
            dVal[idx] = this.getOptionText(idx).toUpperCase();
            if ((inputValue <= dVal[idx])&&((idx == 0)||(inputValue > dVal[idx-1]))) {
                this.selectItem(idx,update,select);
                break;
            }
        }
    }
}

/// Start (or restart) timer normally used by "timer" mode (overridden to apply to all modes)
/// Users should not call this method.
ClientMethod startTimer() [ Internal, Language = javascript ]
{
    this.clearTimer();
    this.actionTimerId = self.setTimeout("zenPage.getComponent("+this.index+").timerHandler()",this.delay);
}

/// Clear timer normally used by "timer" mode (overridden to apply to all modes)
/// Users should not call this method.
ClientMethod clearTimer() [ Internal, Language = javascript ]
{
    if (this.actionTimerId) {
        self.clearTimeout(this.actionTimerId);
        this.actionTimerId = null;
    }
}

/// Timer event handler normally used by "timer" mode (overridden to apply to all modes)
/// Users should not call this method.
ClientMethod timerHandler() [ Internal, Language = javascript ]
{
    if (this.isDropdownVisible) {
        // refresh drop down only if searchKeyLen is not defined!
        if ((this.searchKeyLen != '') && (this.searchKeyLen > 0)) {
            this.renderDropdown();
        } else {
            this.findSelectedItem(); //Just find the selected item.
        }
    }
    else {
        this.showDropdown();
    }
}

/// Change handler for input control.
/// Users should not call this method.
ClientMethod inputChangeHandler() [ Internal, Language = javascript ]
{
    this.invokeSuper('inputChangeHandler');
    
    //If input was cleared, and the actual control value was changed, then clear the value and notify.
    var input = this.findElement('input');
    if (input.value == '') {
        if (this.getValue() != '') {
            this.setValue('');
            this.onchangeHandler();
        }
    }
}

/// Notification that this component is about to stop being modal.
ClientMethod onEndModalHandler(zindex) [ Language = javascript ]
{
    this.findSelectedItem(true,false,true);
    this.invokeSuper('onEndModalHandler',arguments);
}

}

In case you're unfamiliar with custom components: you can include this one in a Zen page like this:

<page xmlns="http://www.intersystems.com/zen" xmlns:demo="http://www.intersystems.com/zen/dc/demo">
<demo:dataCombo sql="select 'your query here'" />
</page>

Or like this:

<page xmlns="http://www.intersystems.com/zen" >
<dataCombo xmlns="http://www.intersystems.com/zen/dc/demo" sql="select 'your query here'" />
</page>

See Fabian's post, "Advanced URL mapping for REST"

This just looks like a bug - the generated code is:

 Do tInstaller.Import(tNSName,tInstaller.Evaluate("${AddonDir}/AddClasses.xml"),"ck","5202","5373","0")

While you would expect:

 Do tInstaller.Import(tNSName,tInstaller.Evaluate("${AddonDir}/AddClasses.xml"),"ck","5202,5373","0")

Here's a possible workaround (untested, but the generated code looks better):

<Var Name="AddClassesErrors" Value="5202,5373" />
<If Condition='#{##class(%File).Exists("${AddonDir}/AddClasses.xml")}'>
  <Import File="${AddonDir}/AddClasses.xml" IgnoreErrors="${AddClassesErrors}" Flags="ck" />
</If>

EDIT: actual workaround (see discussion below) is to use #{<COS_expression>} (see documentation).

<Var Name="AddClassesErrors" Value="#{&quot;5202,5373&quot;}" />
<If Condition='#{##class(%File).Exists("${AddonDir}/AddClasses.xml")}'>
  <Import File="${AddonDir}/AddClasses.xml" IgnoreErrors="${AddClassesErrors}" Flags="ck" />
</If>

Here's a solution that works for me:

s string="http://www.google.com"
set matcher=##class(%Regex.Matcher).%New("(\b(https?|ftp)://[-A-Za-z0-9+&@#/%?=~_|!:,.;]*[-A-Za-z0-9+&@#/%=~_|])",string)
w matcher.ReplaceAll("<a href='$1' target='_blank'>$1</a>")

Key changes:

• Remove the enclosing / /gim - this is part of the regex syntax in JS.
• Add two a-z ranges for case insensitivity
• Remove JS escaping of slashes (not necessary)