MSCRM 4.0 : Convert a Lookup Field to Picklist

If you have any experience with MSCRM, you should be very familiar with CRM lookup as it’s the primary UI control to help you create and manage relationship between two entities that have a 1:N relation.

Overall, CRM lookup field is user friendly and also very informative. But the problem is, it’s not a very productive UI control, as it requires user to go through several mouse clicks to get things done. Today, I am trying to use CRM native lookup and present it as a picklist to help your CRM user become more productive. Give an example, CRM account form has a "Territory" lookup field, user would need to do at least 3 mouse clicks in order to choose a territory record, also she has to be patient enough to wait for the popup lookup window to be loaded.

With the script that I am presenting today, you can convert the lookup into a picklist, which will only requires 2 clicks in most cases. The following is the screen shot after such conversion. Here is the code:

ConvertLookupToPicklist = function(lookupControl, lookupEntityName, lookupEntityPrimaryAttribute) {
    /**
     * CRM Lookup to Picklist Converter 1.0
     *
     * @author Daniel Cai
     * @website http://danielcai.blogspot.com/
     * @copyright Daniel Cai
     * @license Microsoft Public License (Ms-PL), http://www.opensource.org/licenses/ms-pl.html
     *
     * This release is provided "AS IS" and contains no warranty or whatsoever.
     *
     * Date: Oct 27 2009
     */

    var lookupEntityPrimaryKeyField = lookupEntityName + "id";
    
    var RetrieveLookupValues = function() {
        var fetchXml = 
"<fetch mapping='logical'>" + 
   "<entity name='" + lookupEntityName + "'>" + 
      "<attribute name='" + lookupEntityPrimaryKeyField + "' />" + 
      "<attribute name='" + lookupEntityPrimaryAttribute + "' />" + 
      "<order attribute='" + lookupEntityPrimaryAttribute + "' />" + 
   "</entity>" + 
"</fetch>";

        var lookupValues = [];
            
        var fetchResult = CrmServiceToolkit.Fetch(fetchXml);
        if (fetchResult !== null) {
            for( i = 0; i < fetchResult.length; i++) {
                var item = new Object();
                item[lookupEntityPrimaryKeyField] = fetchResult[i].getValue(lookupEntityPrimaryKeyField);
                item[lookupEntityPrimaryAttribute] = fetchResult[i].getValue(lookupEntityPrimaryAttribute);
                 
                lookupValues[i] = item;
            }
        }
        return lookupValues;
    };
    
    var PopulatePicklist = function(picklistControl, lookupValues) {
        picklistControl.options.length = 0;
        
        // Add blank option item
        var option = document.createElement("option");
        option.value = "";
        option.innerText = "";        
        picklistControl.appendChild(option);        
        
        // Add all options from code table (lookup entity)
        if (typeof lookupValues !== "undefined") {
            for (var i = 0 ; i < lookupValues.length ; i++) {
                option = document.createElement("option");
                option.value = lookupValues[i][lookupEntityPrimaryKeyField];
                option.innerText = lookupValues[i][lookupEntityPrimaryAttribute];
                
                picklistControl.appendChild(option);
            }
        }
    };    
 
    (function Convert() {    
        var picklistControl = document.createElement("select");
        picklistControl.id = lookupControl.id;
        picklistControl.name = lookupControl.name;
        picklistControl.tabIndex = crmForm.all[lookupControl.id + '_ledit'].tabIndex;        picklistControl.req = lookupControl.req;
        picklistControl.Disabled = lookupControl.Disabled;
        picklistControl.className = "ms-crm-selectBox";

        var lookupValues = RetrieveLookupValues();
        PopulatePicklist(picklistControl, lookupValues);

        if (lookupControl.DataValue !== null) {
            picklistControl.DataValue = lookupControl.DataValue[0].id;
        }
        
        var lookupControlCell = document.getElementById(lookupControl.id + "_d");
        lookupControlCell.removeChild(lookupControlCell.childNodes[0]);
        lookupControlCell.appendChild(picklistControl);
        return picklistControl;
    })();
};

To use the converter, you simply call it with 3 parameters, the CRM lookup field, lookup entity's name, and lookup entity's primary attribute name, which by default is usually "name" for native entities, or "new_name" for custom entities (assuming that "new" is your customization prefix) unless you have specified a different one. For instance, if you are working with account form as mentioned above, you may want to convert two lookup fields, "Territory" (Details tab) and "Preferred User" (Administration tab), to picklist. You can simply copy the following code to do the job.

ConvertLookupToPicklist(crmForm.all.territoryid, "territory", "name");
ConvertLookupToPicklist(crmForm.all.preferredsystemuserid, "systemuser", "fullname");

A few notes about the script:

• I am again using my CRM Web Service Helper to facilitate CRM FetchXML query. The CRM Web Service Helper was designed as a reusable JavaScript toolkit which tries to make it easy to talk to CRM Web Services in your CRM form script.
• This script gives you a lot more flexibility than using native lookup field. You can use your own query to select what to be displayed in the picklist which is not supported by CRM native lookup out of box. I have previously provided a solution for CRM4 Filtered Lookup, if you need to stick to lookup but you also want filtering on the records being displayed.
• Comparing to CRM native picklist, this picklist is sort of a dynamic list, as user can add / edit / delete any record in the lookup entity, which will then affect the list being displayed in the picklist. This actually makes the lookup entity hehaves like a code table in the 1:N relationship. That is something we are missing on CRM platform at this time.
• Due to the nature of picklist, the lookup entity should not have too many records, so the user doesn't have to go through a long list to pick what she wants. 

Hope you find this script useful.

[UPDATE - Jan 26, 2010] I have updated the script so it uses the latest CRM Web Service Toolkit.
[UPDATE - Mar 23, 2010] I didn't like my previous code very much (it actually stank badly, to be honest), so I did another update of refactoring, hope you like it better.