Remove data merge placeholders with missing data

If anyone is interested, I finally found a kindof hacky way to achieve this. If you got suggestions on how to improve, I am all ears. The principle is looping through all placeholders, comparing them to the contents of the csv and remove the pageItems that contains unused datamerge placeholders.

function removeUnusedDMPlaceholders() {
	var currentPath = app.activeDocument.filePath;
	var csvFile = new File(currentPath+"/"+CSV_FILE);
	csvFile.open('r');
    csvHeader = csvFile.read().split("\n")[0];
    tagsInCSV = csvHeader.split(",");
    itemsToRemove = [];
    storiesInDoc = [];
    
    for(var i=0;i<tagsInCSV.length;i++) {
    	tagsInCSV[i] = tagsInCSV[i].replace('#','').replace('@','');
    }
    
    var dataMergeTextPlaceholders = app.activeDocument.dataMergeTextPlaceholders;
    var dataMergeImagePlaceholders = app.activeDocument.dataMergeImagePlaceholders;
    var dataMergeQrcodePlaceholders = app.activeDocument.dataMergeQrcodePlaceholders;

	for(var i=0; i<dataMergeTextPlaceholders.length; i++) {		
		if(typeof dataMergeTextPlaceholders[i] != 'undefined') {
			if(dataMergeTextPlaceholders[i].isValid) {
				if(typeof dataMergeTextPlaceholders[i].field != 'undefined') {
					try {
						tagsInDoc.push(dataMergeTextPlaceholders[i].field.fieldName);
					} catch(error) {
					}
				}
			}
		}
	}
	for(var i=0; i<dataMergeImagePlaceholders.length; i++) {
		if(typeof dataMergeImagePlaceholders[i] != 'undefined') {
			if(dataMergeImagePlaceholders[i].isValid) {
				if(typeof dataMergeImagePlaceholders[i].field != 'undefined') {
					try {
						if(!contains(tagsInCSV,dataMergeImagePlaceholders[i].field.fieldName)) {
							itemsToRemove.push(dataMergeImagePlaceholders[i].placeholderPageItem);
						}
					} catch(error) {
					}
				}
			}
		}
	}
	for(var i=0; i<dataMergeQrcodePlaceholders.length; i++) {
		if(typeof dataMergeQrcodePlaceholders[i] != 'undefined') {
			if(dataMergeQrcodePlaceholders[i].isValid) {
				if(typeof dataMergeQrcodePlaceholders[i].field != 'undefined') {
					try {
						if(!contains(tagsInCSV,dataMergeQrcodePlaceholders[i].field.fieldName)) {
							itemsToRemove.push(dataMergeQrcodePlaceholders[i].placeholderPageItem);
						}
					} catch(error) {
					}
				}
			}
		}
	}

	var pages = app.activeDocument.pages;

	for(var i=0; i<pages.length; i++) {
		var textFrames = pages[i].textFrames;
		for(var j=0; j<textFrames.length; j++) {
			var textContents = textFrames[j].texts[0].contents;
			var result = textContents.match(/\<\<(.*?)>>/g);
			if(result != null) {
				result = result[0].replace("<<","").replace(">>","");
				if(!contains(tagsInCSV,result)) {
					try {
						textFrames[j].remove();
					} catch(error) {
					}
				}

			}
		}
		var pageItems = itemsToRemove;
		for(var j=0; j<pageItems.length; j++) {
			if(typeof pageItems[j] != 'undefined' && pageItems[j].isValid) {
				try {
					pageItems[j].remove();
				} catch(error) {
				}
			}
		}
	}
}

function contains(a, obj) {
    for (var i = 0; i < a.length; i++) {
        if (a[i] === obj) {
            return true;
        }
    }
    return false;
}