Dynamically Modify FetchXML Using JavaScript in Dynamics 365 CRM#

Recently I got into a requirement to conditionally manipulate the fetchxml’s filter condition on runtime using client-side JavaScript and process the results. Let’s walk through the steps to implement the fetchxml parser logic.

Steps to implement the logic#

• Store the required fetchXML query in a variable fetchQuery.
• Parse it as XML.
• Check if a <filter> node already exists inside the <entity> node.
• If it exists, append a new <condition> node inside the existing <filter> node.
• If it doesn’t, create a new <filter> node, add your <condition> node to it, and append it to the <entity> node.

Parse the FetchXML string#

var fetchQuery = "YOUR_FETCHXML";
var myParser = new DOMParser();
var parsedXML = myParser.parseFromString(fetchQuery, "text/xml");

This converts the FetchXML string into an parsedXML object that can be manipulated.

Create a new <condition> node#

var newConditionNode = document.createElement("condition");
newConditionNode.setAttribute("attribute", "quoteid");
newConditionNode.setAttribute("operator", "eq");
newConditionNode.setAttribute("value", quoteId);

This condition filters records where quoteid == quoteId.

If a <filter> node exists, append the condition node to it.#

var filterTagFoundFlag = false;
parsedXML.getElementsByTagName("entity")[0].childNodes.forEach(function (xmlnode) {
    if (xmlnode.tagName == "filter") {
        filterTagFoundFlag = true;
        xmlnode.appendChild(newConditionNode);
    }
});

If no <filter> node was found, create a new node, add the condition to the new node using appendChild(), and append it to the <entity>.#

if (filterTagFoundFlag == false) {
    var newFilterNode = document.createElement("filter");
    newFilterNode.setAttribute("type", "and");
    newFilterNode.appendChild(newConditionNode);

    parsedXML.getElementsByTagName("entity")[0].appendChild(newFilterNode);
}

Rebuild the FetchXML string and remove unwanted namespace attributes#

var myResultQuery = parsedXML.documentElement.outerHTML.replaceAll('xmlns="http://www.w3.org/1999/xhtml"', "");

Usage of this code#

I have implemented a very basic sample to append filter condition to the fetchxml which can be extended to implement complex solutions and I hope this solution might be useful for below scenarios.

• When building dynamic queries based on user inputs
• Reusing same filters for dynamic reports, Form scripts, Subgrid filters etc
• Ribbon button JavaScript
• Custom Web resources, PCF Controls when dynamic filtering is required