Using MISMO's iLAD XML Schema
October 16, 2019
This is the third article of a series about the new Industry Loan Application Dataset (iLAD) specification which was released by MISMO® (Mortgage Industry Standards Maintenance Organization) on September 4th2019. iLAD is expected to replace the Fannie Mae 3.2 file specification as the standard for exchanging loan application data. The first two articles provided an overview of ILAD and described the specification worksheet file. This article describes how to use the iLAD XML Schema Files to map data between iLAD and your own internal XML schemas.
What Are XML Schema Files Used For?
Schema files provide a standard way for defining how a data set is structured and organized, in other words, it defines the shape and format of the data. That specification is essential to allow different systems to communicate with each other.
Downloading and Extracting the iLAD 1.0.0 Files
MISMO's Industry Loan Application Dataset (iLAD) web page provides two download links:
- iLAD industry Loan Application Dataset version 1.0.0 dated 08272019.xslx
This link downloads the iLAD Specification worksheet, which was reviewed in an earlier article, Exploring the iLAD Specification.
- iLAD Wrapper Schema V1 20190827.zip
This second link download a compressed archive (zip file) that contains the files that comprise the iLAD XML Schema.
Click on the link to download the iLAD Wrapper schema to your computer and then unzip it to a file folder. Here is a description of the folder's content:
iLAD Wrapper Schema File
MISMO XML Schema Files
Schema Extension Files
iLAD XML Sample File
Setting up Grid-ML Schema Viewer
Entities implementing the iLAD Specification will probably need to create a data mapping specification to describe how to map iLAD to their own internal data schemas. For this article, I will use the Grid-ML online schema viewer, because it allows for simultaneously searching of multiple schemas side-by-side.
Setting up the iLAD Schema
After logging in to Grid-ML, click on the Setup Schemas button. In the Schema Setup page, drag the iLAD folder onto the appropriate area onscreen and then select the “iLAD_Schema_Wrapper_V1.xsd” file as the primary schema file. This will allow all of the iLAD, ULAD, DU and LPA data elements to be searched in addition to the MISMO data elements.
Grid-ML XML Schema Setup Screen
When you click Next, Grid-ML looks inside the primary schema file and automatically detects all secondary files that it includes or imports. Grid-ML then shows you the list of files that will be uploaded. Click Upload to upload the files to Grid-ML.
The final setup step is to choose which schema “root” element(s) to search. For this article, we are focused on data elements at the “DEAL” level only.
Grid-ML Root Element Selection
Setting up your Internal XML Schema
After loading the iLAD schema, you can also load your own internal schema. This allows you to search both schemas at the same time to find how related concepts are represented on each schema. To load you internal schema, just follow the same steps as above, but instead of selecting the iLAD files, use the files that define your own schema. Grid-ML allows you to setup as many schemas as you want.
In the examples below, I use a fictional “ACME Mortgage” internal data schema to illustrate that data mapping process. ACME Mortgage uses an internal data exchange format that uses MISMO elements plus additional ACME data elements that are not part of the MISMO specification.
Creating a Data Mapping Worksheet
Below is a simplified data mapping worksheet where we will list the iLAD data elements used by our fictional ACME Mortgage and their equivalent internal data elements. These data mapping worksheets are typically used by software developers who create the code to transform the data between a industry standard schema and their internal data exchange or storage formats.
iLAD Sample Data Mapping Worksheet
Searching the Schemas for Data Elements
First, we’ll search for the BankruptcyCount element. Grid-ML finds one match in ACME_XML schema and one in the iLAD DEAL data structure.
Sample Multi-Schema Search
Copying the the iLAD XPath into the Data Mapping Worksheet
- From the Grid-ML screen, select the iLAD DEAL tab.
- In the search results column, select the ilad:BankruptcyCount element.
- In the locations column, drill down into the PARTIES element and select the parent container for for the ilad:BankruptcyCount element.
- Click Copy Full Path.
- Go to the data mapping worksheet and simply right-click on the iLAD XPath column cell to paste the path value you copied from Grid-ML.
Worksheet with iLAD Container XPATH
Copying the iLAD Element Name and Definition to the Data Mapping Worksheet
- From the Grid-ML screen, turn on the “Copy Item Definition” check box
- Click Copy Node Name.
- Go to the mapping worksheet and simply right-click on the iLAD Data Element cell to paste the data element name and definition simultaneously.
Copying iLAD XPATH with Element Definition
Worksheet with iLAD XPATH, Element Name and Definition
Copying Internal XPath, Element Name, and Definition to the Data Mapping Worksheet
To copy and paste the equivalent ACME Mortgage data specification, select the “ACME_XML” tab in the Grid-ML search screen and follow the same steps as described above.
Copying Internal XPATH, Element Name and Definition
The complete data mapping specification for the ilad:BankruptcyCount element should look like this:
Complete Data Mapping Specification for an iLAD Element
Mapping Additional Elements
This process can be repeated for all of the data elements needed for the iLAD – ACME data exchange. One of the advantages of using a tool like Grid-ML to build the data mapping worksheet is that it uses the XML schema files directly and eliminates spelling and other errors that are typical when using manual data entry or pasting from sources other than the data schema itself.
Locating Extension Data Using Grid-ML
As noted earlier, the iLAD schema contains MISMO extensions that support the iLAD, ULAD, DU and LPA data elements that were not part of the MISMO v3.4.0 Reference Model. Within the schema file, data elements for each of these extension types are tagged with what is called a “namespace prefix”. The table below lists the namespace prefix for each extension type.
|DU (Fannie Mae)
|LPA (Freddie Mac)
To search for the data elements of a specific extension type, simply enter the namespace prefix at the Grid-ML Search for: prompt and the data elements with that extension type will immediately display. The example below shows the results when searching for ILAD extension elements. This can be repeated for any of the extension types:
Searching for iLAD Extension Elements
iLAD Versions – What’s Next?
Version 1 of the iLAD specification has been published by MISMO and contains the data elements that were part of the ULAD, DU, LPA, and Fannie Mae 3.2 “Flat File”. The Version 1 scope was limited so that it could be available to mortgage industry service vendors in a timely manner.
The MISMO Loan Application Data Exchange workgroup is already working on the next version of iLAD. Some of the additional data under consideration is the government agency data such as USDA Rural Housing, VA, or other mortgage data that is currently collected using proprietary data formats, paper forms or manually entered into data entry screens.
This MISMO development workgroup currently has conference call meetings every Tuesday from 1 – 2pm Eastern. MISMO members can find this workgroup’s meeting agendas, discussion posts and file library at the group’s home page. To become a MISMO member, more information can be found on the MISMO web site’s Join MISMO web page.
Mike Bixby is the president of Bixby Consulting Inc. which has been providing data integration support to the mortgage industry for over twenty years. Mike was one of the founding members of MISMO and has served on MISMO's Residential Governance Committee, MISMO's Board of Directors and was the Chair of MISMO's Credit Reporting Workgroup from 2000– 2010. Mike is also the Chair of MISMO's Information Management team, which reviews and approves all changes to the MISMO Reference Model, Logical Data Dictionary, Implementation Guides, and other MISMO products. Mike Bixby is also a partner in GridML LLC, which developed the Grid-ML XML Schema Viewer