Saturday, May 20, 2017

Making CrmWebApi Entity References Suck Less For Creates and Updates

For those that “grew up” on the 2011 Rest endpoint for CRM, attempting to populate Entity Reference attributes for create or update calls feels rather painful in the new CrmWebApi.
account["primarycontactid@odata.bind"] = "/contacts(E15C03BA-10EC-E511-80E2-C4346BAD87C8)";
Was it “"@odata.bind” or “@bind.odata”? Was it a forward slash or backward slash?  Did the Guid have curly braces?

Yes it’s a small pain, but it is bigger if you normally use field accessors (“entity.field” rather than array accessors: “entity[‘field’]”) because "account.primarycontactid@odata.bind" isn't a valid field name.  It’s probably because of my C# background, but I prefer not to use the object array accessor method when possible.  So the question is, how to make this syntax better and help me remember it.

On my current project I use David Yack’s CRMWebAPI.  It’s simple, and uses standard Promises, so no need for a new library, just polyfill Promises (if you’re using IE 11) and you’re all set.  The calls are wrapped by a custom TypeScript library (CrmWebApiLib) to allow for some custom changes, of which, this implementation is one.  First, the library defines an Entity Reference class (*Note, this is TypeScript, get it, use it, love it)
export class EntityReference implements ODataFormattable {
    constructor(public collectionName: string, public id: string) { }
 
    toODataFormat = (): string => {

        return `/${this.collectionName}(${CrmWebApiLib.removeCurlyBraces(this.id)})`;
    }
 
    getODataPropertyName = (propertyName: string): string => {
        return `${propertyName}@odata.bind`;
    }
}
The class has two public properties, “collectionName” and “id”, and implements the two functions of the ODataFormattable interface, “toODataFromat” and “getODataPropertyName”.  The toODataFormat adds the forward slash and formats the guid correctly, and the getODataPropertyName appends the “@data.bind” to the property name parameter.

The ODataFormattable interface just defines the two functions.  Then there is also a User Defined Type Guard to determine if any given object implements the ODataFormattable interface:
export interface ODataFormattable {
    toODataFormat(): string;
    getODataPropertyName(propertyName: string): string;
}

export function isODataFormattable(arg: any): arg is ODataFormattable {
    const formattable = arg as ODataFormattable;
    return formattable && formattable.toODataFormat !== undefined && formattable.getODataPropertyName !== undefined;
}
This then is all used in the prepareForOData function:
/**
 * Loops through properties, searching for any ODataFormattable properties or arrays with ODataFormattable, and updates the format to be OData Friendly
 * @param data
 */
function prepareForOData(data: any): any {
    const oData = {};
    for (const propName in data) {
        if (!data.hasOwnProperty(propName)) {
            continue;
        }
 
        const value = data[propName];
        if (isODataFormattable(value)) {
            oData[value.getODataPropertyName(propName)] = value.toODataFormat();
        } else if (value instanceof Array) {
            oData[propName] = value.map(prepareForOData);
        } else {
            oData[propName] = value;
        }
    }
    return oData;
}
It creates a new object, and basically loops through all properties of the data object, copying it over to the new object.  If the value of the property is a ODataFormatable, it will update the value as well as the property name.  There is then a recursive map call to handle arrays as well (think party lists).  prepareForOData is then called from within the create and update methods:
export function create(entityCollection: string, data: any): Promise<any> {
    return instance().Create(entityCollection, prepareForOData(data));
}
 
export function update(entityCollection: string, key: string, data: any, upsert?: boolean): Promise<any> {
    if (key.indexOf("{") >= 0 || key.indexOf("}") >= 0) {
        key = CrmWebApiLib.removeCurlyBraces(key);
    }

    return instance().Update(entityCollection, key, prepareForOData(data), upsert);
}
And now, these two calls, will result in the same exact request made to the CrmWebApi:

No Bueno
const note = {};
note["notetext"] = CommonLib.getValue(fields.description);
note["objectid_allgnt_location@odata.bind"] = `/allgnt_locations(${CommonLib.getSelectedLookupId(fields.location)})`;
CrmWebApiLib.create("annotations", note);

Muy Bueno
const note = {
    notetext: CommonLib.getValue(fields.description),
    objectid_allgent_location: new CrmWebApiLib.EntityReference("allgnt_locations", CommonLib.getSelectedLookupId(fields.location))
};
CrmWebApiLib.create("annotations", note);

Monday, May 1, 2017

How To Add Custom Filters That Are Asynchronous In Dynamics 365 Customer Engagement

Adding custom filters to lookup entities isn’t entirely simple.  It involves adding a trigger to the PreSearch function in which a call is made to set the filter on the control using addCustomFilter. The PreSearch event must be synchronous since it is triggered once the user has selected the lookup, and needs to apply the filter right then. 

But what if you want to do something like query the lookup entity for the given filter, and relax the criteria if nothing is found (i.e. Search by First and Last name, unless no match is found, then search by Last Name only).  That either involves a blocking synchronous call (Yuck), or some form of black magic to make something asynchronous behave synchronously.  Well, maybe not black magic, just 40 lines of TypeScript:

const _preSearchFilters = {} as { [index:string]:string };
 
/**
 * Handles adding a PreSearch that is Asynchronous.  To be called in the onLoad of the form.  This will trigger the getFilter method to attempt to assign the filter.
 * The Lookup Attribute will be disabled until the getFilter method has finished executing
 * @param info Object that contains the following properties:
 *             control - Name of the lookup control to add the PreSearch Filter for.
 *             filteringEntity - If entityLogicalName is not specified, the filter will be applied to all entities valid for the Lookup control.
 *             getFilter - Function that returns the Promise of the filter Xml.
 *             triggeringAttributes - List of attributes, that if changed, will result in the filter needing to be updated.

 */
export function addAsyncPreSearch(info: { control: string, filteringEntity?: string, getFilter: () => Promise<string>, triggeringAttributes?: string[]}) {
    const setAsyncFilter = async () => {
        const enablePostFilter = !Xrm.Page.getControl(info.control).getDisabled();
        if (enablePostFilter) {
            Xrm.Page.getControl(info.control).setDisabled(true);
        }
 
        try {
            _preSearchFilters[info.control] = await info.getFilter();
        } catch (e) {
            console.error(`Error occurred attempting to get the preSearch filter for ${info.control}`, e);
            _preSearchFilters[info.control] = "";
        } finally {
            if (enablePostFilter) {
                Xrm.Page.getControl(info.control).setDisabled(false);
            }
        }
    };
 
    Xrm.Page.getControl(info.control).addPreSearch((context: Xrm.Page.EventContext) => {
        const ctrl = (context.getEventSource() as Xrm.Page.LookupControl);
        if (ctrl && ctrl.addCustomFilter) {
            ctrl.addCustomFilter(_preSearchFilters[ctrl.getName()], info.filteringEntity);
        }
    });
 
    if (info.triggeringAttributes && info.triggeringAttributes.length > 0) {
        for (const att of info.triggeringAttributes) {
            Xrm.Page.getAttribute(att).addOnChange(setAsyncFilter);
        }
    }
 
    setAsyncFilter();
}

That’s a lot of code, let’s walk through it.

First, a module level field (_preSearchFilters) that stores the filters for each control is declared and instantiated (note there is an assumption that you will only ever have one filter per control, which I think is pretty safe).  For those of you new to TypeScript, “{ [index:string]:string }” is how you define that the field is an object, which is indexable by a string, returning string.  This would be equivalent to a C# Dictionary<string,string>.

Next is a nested function “setAsyncFilter” that wraps the async function “getFilter” that is passed in.  It handles 2 things, disabling the control until the async function finishes, and storing the result of the async function in the “_preSearchFilters”.  If the control doesn’t get disabled, then there is a chance that the user could attempt to perform a search the async function determines what the filter should actually be.

After the “setAsyncFilter” definition comes the first code that is actually executed, a call to get the control, and add an anonymous function as a preSearch.  The function just calls “addCustomFilter” on the control that triggered the action, with the optional filteringEntity parameter.

Next to last is an if statement to trigger the “setAsyncFilter” function, each and every time a field is updated that could potentially change the filter.  This if followed by the last step, a call to “setAsyncFilter” to initialize the value in the “_preSearchFilters: field.

To use this function, just call it in the onLoad of the form:

CommonLib.addAsyncPreSearch({
    control: Lead.fields.installFee,
    filteringEntity: "new_installationfee",
    getFilter: getInstallationFilter,
    triggeringAttributes: [Lead.fields.campaign,
                           Lead.fields.callType]
});
The call above adds an Async PreSearch to the installFee control.  The filter is to be applied to the “new_installationfee” entity, and is generated by the Promise returning function, “getInstallationFilter”.  Finally, a trigger is added to refresh the filter whenever the campaign or callType fields are updated.  That's it.

Chalk one up to TypeScript for handling the async/await.  Just don’t forget to polyfill your Promise call, or your IE 11 users won’t be too happy Winking smile

Friday, April 28, 2017

Refactor Makes “Perfect”

I was recently doing a unit test of some Typescript logic for a Form in Dynamics 365 for Customer Engagement (Hereafter referred to as CRM).  Our CRM instance maintains a list of Localities and when a user selects a State/County it should perform different actions based on the number of localities found for the state/county combination:

  • 1 found: Set the Lookup to the single Locality 
  • 1+ found: Filter the Localities Lookup by state and county
  • 0 found: Filter the Localities Lookup only by state and allow the user to choose.

In writing the test case for the first lookup, this is what I came up with at first:

it("should set locality if a single locality exists for the state/county", async (done) => {
    spyOn(restLibMock.CrmWebApiLib, "getList").and.callFake((r) => CrmWebApiLibStubs.getList.defaultValuesUsingSelect(r, 1));
    new Squire()
        .mock(restLibMock.path, restLibMock)
        .require(["dfnd_/scripts/lead/CustomerStage"], async (m: { CustomerStage: typeof CustomerStage }) => {
            await m.CustomerStage.setLocalityFilter();
            expect(CommonLib.getValue(LeadCommon.fields.locality)).toBeTruthy("because the locality should have been set because only one locality exists for the given city/state");
            done();
        });
});

It works, but it sucks:

  • It’s really confusing (I’m going to explain it line by line, and you still probably won’t understand it)
  • A lot will need to be duplicated to handle the other 2 cases.

First thing it does is setup a fake for the CrmWebApiLib module in restLibMock using a Jasmine Spy.  The fake “defaultValuesUsingSelect” just returns an result where the fields selected are populated with their own values, and the 1 just means that one item should be returned:

spyOn(restLibMock.CrmWebApiLib, "getList").and.callFake((r) => CrmWebApiLibStubs.getList.defaultValuesUsingSelect(r, 1));

The next 3 lines are setup for injecting the mock as CrmWebApiLib module, into CustomerStage.  It accepts a callback with a parameter that has a CustomerStage Property that has the mock CrmWebApiLib injected:

new Squire()
    .mock(restLibMock.path, restLibMock)
    .require(["scripts/lead/CustomerStage"], async (m: { CustomerStage: typeof CustomerStage }) => {

The final lines are the actual test that needs to be performed.  Call setLocalityFilter, and verify that that Locality attribute has had it’s value set:

await m.CustomerStage.setLocalityFilter();
expect(CommonLib.getValue(LeadCommon.fields.locality)).toBeTruthy("because the locality should have been set because only one locality exists for the given city/state");
done();

Even if you do understand how this works now, I’d be willing to bet the “future you” who looks at it in 5 days, will require significant time/energy to re-figure out what it’s doing.  No bueno.

Here is the refactored version with the helper method:

it("should set locality if a single locality exists for the state/county", async (done) => {
    const sut = await getCustomerStageWithMockedCrmWeb(1);
    await sut.setLocalityFilter();
    expect(CommonLib.getValue(LeadCommon.fields.locality)).toBeTruthy("because the locality should have been set because only one locality exists for the given city/state");
    done();
});
function getCustomerStageWithMockedCrmWeb(numResults: number): Promise<typeof CustomerStage> {
    return new Promise((resolve) => {
        spyOn(restLibMock.CrmWebApiLib, "getList").and.callFake((r) => CrmWebApiLibStubs.getList.defaultValuesUsingSelect(r, numResults));
        new Squire()
            .mock(restLibMock.path, restLibMock)
            .require(["scripts/lead/CustomerStage"], (m: { CustomerStage: typeof CustomerStage }) => {
                resolve(m.CustomerStage);
            });
    });
}

The actual test method is now dead simple, Get the SUT (Subject Under Test), set the locality filter, and assert that the locality was set and the new helper method “getCustomerStageWithMockedCrmWeb” can now be reused in the other three calls with minimal coding required/repeated.  If “future you” looked at that code in 5 months, it would immediately make sense.    Refactor, Refactor, Refactor.

why-refactor-code

Friday, March 10, 2017

I’ve Been Doing Plugin Parameters Wrong For 7 Years

TLDR: Use request/response classes to get typed parameters in your plugins, and share your knowledge!

I’ve been an active Stack Overflow (SO) user for about 7 years now.  There are 3 ways to increase your knowledge from SO.
  1. Being able to ask a question and get an answer in hours.  It’s not always the correct, or the answer you want, but more often than not, it is a great way to increase your knowledge.  This though, is not the primary conduit to increasing your knowledge, that privilege belongs to way #2.
  2. Finding the answers to the questions that have already been asked, and instantaneously getting the knowledge you want (sometimes by the former, “smarter” you).  This is by far the most common method of learning on SO.  It also brings up a new not quite as beneficial coding paradigms (Stack-Overflow-Copy-and-Paste-Yourself-to-Victory).  If this second option is the bread and butter of learning for developers today, then third option is the dessert, the unexpected delightfulness that makes the SO community a great place to contribute to, and learn from.
  3. Providing an answer to a question that you believe to be 100% correct, but then having someone else respond with an even better/more awesome/even more “correcter” answer, to which you tweet about, and then someone else responds with an even better/more awesome/even more “correcter”/more ludicrous answer.  This third option is the subject of today’s post.
Here is how this particular instance of #3 went down…

  • I posted an answer to a SO question about plugin parameters almost 6 months ago (Feel free to refer to the SO question mentioned here: How to know what InputParameters values are possible in Dynamics CRM Plugin context?).  
  • Then Federico Jousset commented on my answer with a helper web page that he has created that is a better tool, IMHO, to answer the OP’s question.  
  • I then tweeted about it (since this knowledge should be shared among the global Dynamics 365 community).
  • Martin Tange responded with a blog post (which I’m assuming he wrote in direct response to my tweet) that brought to light how I’ve been doing plugin parameters wrong since day one.
  • And now you're here learning about it as well!

The MSDN documented approach to accessing parameters is to use “magic” strings and assumed casting
// The InputParameters collection contains all the data passed in the message request.
if (context.InputParameters.Contains("Target") && context.InputParameters["Target"] is EntityReference)
{
    // Obtain the target entity from the input parameters.
    EntityReference entity = (EntityReference)context.InputParameters["Target"];
}
Martin’s technique is so simple, I can't believe I haven't seen it used before:
var createReq = new CreateRequest { Parameters = context.InputParameters };
createReq.Target; // Is typed as Entity vs EntityReference (DeleteRequest)
To which I’ve wrapped in an extension method to help remove some additional key strokes (which I’ve added to the DLaB.Xrm.Plugin namespace):
/// <summary>
/// Populates a local version of the request using the parameters from the context.  This exposes (most of) the parameters of that particular request
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="context">The context.</param>
/// <returns></returns>
public static T GetRequestParameters<T>(this IPluginExecutionContext context) where T: OrganizationRequest
{
    var request = Activator.CreateInstance<T>();
    request.Parameters = context.InputParameters;
    return request;
}
 
/// <summary>
/// Populates a local version of the response using the parameters from the context.  This exposes (most of) the parameters of that particular response
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="context">The context.</param>
/// <returns></returns>
public static T GetResponseParameters<T>(this IPluginExecutionContext context) where T : OrganizationResponse
{
    var response = Activator.CreateInstance<T>();
    response.Results = context.OutputParameters;
    return response;
}
So now, this is even shorter:
var parameters = context.GetRequestParameters<CreateRequest>();
parameters.Target;
So my challenge to you dear reader, get involved in your community.  You may never know when an attempt to share your knowledge with someone else, ends up unexpectedly resulting in others sharing their knowledge with you!