Compare modified values on Save

Hi,

What if you want know whether a field is modified when you click on Save in CRM entity record form, it is simple, check the IsDirty property of the field, as in

if( crmForm.all.field.IsDirty == true) ...

what if you wanted to compare the modified value with the original value that was on Load when you click on Save, a pre-update callout/plugin seems to emerge as a candidate, but you can also do it through clientscript, all you need to do it so find a way to store the value of the original value of the field on Load and use it in your On Save script.

An obvious choice would be to use a hidden field, but for that we have to keep a spare attribute in the entity schema which means it will add an extra column to the entityExtensionbase table in CRM database, just to store a temporary value, doesn't sound good.

What we can do as an alternative is save it in a temporary html element that can be generated on-the-fly just when the form Loads, see how it is done:

On Load script:


initial_value = crmForm.all.field.DataValue;

var new_element = document.createElement('INPUT');

var outertext =
" < input type='hidden' " +
" id='temp_tag' value=' " +
initial_value +
"' />";

var idval = "temp_tag";
var typ = "hidden";



var tagId = document.createAttribute('id');
var tagType = document.createAttribute('type');


var outerHtml = document.createAttribute('outerHTML');

new_element.setAttribute(tagType,typ);
new_element.setAttribute(tagId,idval);
new_element.setAttribute(outerHtml,outertext);

document.getElementsByTagName('body')[0].appendChild(new_element);

This will add a new hidden element on the form when it loads, and it contains the value of your field, once you are done modifying it, you click on Save, you check whether it has been edited and compare it with the old value:

On Save script

if(crmForm.all.field.IsDirty==true)
{
var new_value = crmForm.all.field.DataValue;

//And you get the old value from the element you created on load
//Apparently, the element that you added is the last to be added to the form, hence you can retrieve it as the last element in the document's tag list

var element_array = document.getElementsById('input').length
var count = document.getElementsById('input').length;
var your_element = element_array[count-1];

//Now you have your element, read it's outerHTML property that contains your old value

var old_value = your_element.outerHTML;

//Please note that you get a tag and not the actual value in this outerHTML, so you have to do some string operation to retrieve it in its purest, non-adulterated form

// In my case, I split the tag string with single quote, returning an array of strings, just find out which place is your value, it was at position 5 in my case.

old_value = old_value.split("'")[5];

}

Now you have the new value as well as the old value, use it for any validation logic you want.