The Fall Stable 1 release makes a slight tweak to the way you can use getReference that can really improve the end user experience from a performance perspective. To understand why this new functionality is so important, you must first understand the difference between synchronous and asynchronous processing.
Asynchronous processing, on the other hand, allows for step 2 to start even when step 1 is still in process. These are 2 common out-of-box configurations that most every client ends up using. While the functions work great, they can also be very expensive from a performance perspective in part because they both use synchronous processing to call back to the server and request information.
When this happens, the entire user session has to wait for this processing to complete. Step 2 populating the location and indicating a VIP cannot start until Step 1 querying the server for user information finishes. What this does is allow you to use asynchronous processing with your getReference call.
So when your script executes, the system initiates the necessary query Step 1but continues right along with everything else instead of waiting for the result from the getReference call. Eventually, that call will return with a result though. Today I created the script below. The major benefit to this script is that it combines the 2 scripts and completely eliminates one of the GlideRecord queries to the server.
That alone is a pretty big deal. The second thing this script does is use the new getReference callback function to process the server call asynchronously and keep the form from locking up while your user waits for a result. There are 4 major pieces to the script below that I think are really important…. Save my name, email, and website in this browser for the next time I comment.
Sign me up for the mailing list! Leave this field empty. Previous Next. About the Author: Crossfuze Admin.Sometimes you want to use a gliderecord query from within a client script. In that case make sure you use a callback function. Looking at the timing diagram below we can see the difference.
CS1 needs ms to retrieve the data from the server and then needs around ms to process the result. During all this time the browser cannot do anything else. CS2 needs ms, but is not blocking the next query.
A display business rule would be the better solution to get the information to the client on form loads. Name required. Mail will not be published required. Jul Client scripting — gliderecord query using a callback function General Add comments by: Marc Herni.
However, improperly implemented client scripts can significantly slow down form load times. Follow these best practices to ensure Client Scripts work efficiently. Client scripts without a function cause issues with variable scope. When code is not enclosed in a function, variables and other objects are available and shared to all other client-side scripts.
Scripting in ServiceNow Fundamentals
If you are using the same variable names, it is possible that they could collide. This can lead to unexpected consequences that are difficult to troubleshoot. Client Scripts have no condition field. This means onLoad and onChange scripts run in their entirety every time the appropriate form is loaded. To avoid running time-consuming scripts unnecessarily, make sure client scripts perform only necessary tasks.
The following steps provide examples showing how to prevent the client script from running unnecessary code:. Look for performance optimizations. For example, the getReferenceor GlideRecord lookup can be replaced with an asynchronous GlideAjax call. The isLoading flag is the simplest way to prevent unnecessary code from taking up browser time. The isLoading flag should be used at the beginning of any script which is not required to run when the form is loading.
There is no need to run this script on a form load because the logic would have already run when the field was last changed. The newValue check tells scripts to continue only if there is a valid value in the relevant field. This prevents the scripts from running when the field value is removed or blanked out. This also ensures that there will always be a valid value available when the rest of the script runs.
To have the script react to a value which changes after the form loads, use the newValue! The GlideAjax call can be buried a few levels deeper by rearranging the script to check as many things available to the client as possible before running the server calls.
The script checks the assignment before executing the GlideAjax call. Client scripting uses either data available on the client or data retrieved from the server. Use client data as much as possible to eliminate the need for time-consuming server lookups. However, these methods are no longer recommended due to their performance impact.
Both methods retrieve all fields in the requested GlideRecord when most cases only require one field. Synchronous AJAX methods e. Use the asynchronous glideAjax.
What's here.Using methods in the GlideRecord API, you can return all the records in a table, return records based on specific conditions or keywords, or return records from multiple tables with a single query.
Creating a GlideRecord creates a target variable which is a GlideRecord object for the incident table. This script issues the query to the database.
Each call to next would load the next record for processing. For example, this script returns records from the Incident table that include the 'email' keyword. For example, instead of addQueryyou can also use gr.
A text index group is a group of tables that the system indexes together and searches across. For more information about text index groups, see Configure multiple tables for indexing and searching. For example, this script returns records that include the keyword 'email' in the 'portal' index group.
For example, instead of addQueryyou can use gr. Describes the operators that can be used within an addQuery request. For additional information on the operators that are available for filters and queries, see Operators available for filters and queries. These examples demonstrate how to perform various GlideRecord queries. For additional information see GlideRecord. Note: Before querying a table or an index group, you must configure text indexing and search attributes for one or more tables you want to search.
GlideRecord Query Cheat Sheet
For more information, see Configure a single table for indexing and searching or Configure multiple tables for indexing and searching. To query a table, first create a GlideRecord object. To process all records from the incident table, add the following script: target. Most of the time, you want to retrieve a specific record or a specific set of records, and you have some criteria query conditions that define the records you want to obtain. For example, say that you want to obtain all the incident records that have a priority value of 1.
Here is the code that would accomplish that. Notice that the example script includes target. This line indicates that you only want the records where the priority field is equal to 1.
In general, most queries that you want to perform are equality queries; queries where you want to find records with a field equal to a value. For this reason, you do not need to provide an equality operator. However, lets say you wanted to find all incidents where the priority field is greater than 1. In this case, you would provide the operator that you want to apply to the query.Call Script Include from Client Script in ServiceNow using GlideAjax
If you have any creative uses of GlideAggregate, please feel free to share them in the comments! And as always, never hesitate to ask any questions you might have. Categories: DevelopersScripting Tips. You are commenting using your WordPress. You are commenting using your Google account. You are commenting using your Twitter account. You are commenting using your Facebook account. Notify me of new comments via email.
Notify me of new posts via email. For example, I can write a query to only return users that have at least 10 active tasks assigned to them. Share this: Twitter Facebook Reddit.
Like this: Like Loading Leave a Reply Cancel reply Enter your comment here Fill in your details below or click an icon to log in:. Email required Address never made public. Name required.Access fields on a related table from a form, list, or script by dot-walking. This topic includes examples of the different ways you can dot-walk.
You can dot-walk to related fields in a list, such as the field list in a filter. This example demonstrates how to filter the Incident [incident] table by the company of the caller who registered the incident. The example shows that the user is at Incident. You can return to higher levels in the hierarchy by selecting fields located at the top of the menu. For instance, selecting Incident fields returns to the list of incident fields.
To dot-walk in a condition builder, first select Show Related Fields on the fields menu. This action allows you to add fields from related tables to your query. The following GIF shows how you would dot-walk fields in a condition builder to find all Incident records assigned to one specific user, Beth Anglin. The user opens the fields menu again to select Last name. The user builds the following condition: [Last name] [is] [Anglin]. After the user selects Runthe Incident list displays only the records assigned to Beth Anglin.
For scripts that run on the server side, such as business rules, it is necessary to add current. Often, you can add variables into templates, notifications, or other forms where a value is being called from the form. As shown in the example, you can dot-walk to fields on the original record of any reference field. The following example shows how you would use a tree picker to assign an Incident record to a user in the Database group. You would first navigate to any Incident record and then enter Database in the Assignment group field.
In this example, the Database group is a parent group with multiple child groups under it. When you select the search icon next to the Assigned to field, a window displays reference fields in the Database group. In this example, expanding the Database Atlanta or Database San Diego fields opens a list of user records within each child group.
You would select any one of the user records to add it as a value in the Assigned to field. List fields You can dot-walk to related fields in a list, such as the field list in a filter. When you open the list of fields that you want to filter, you see the list of available Incident table fields. The reference fields are followed by the related fields.
If the related fields are not present in the list, you would select Show Related Fields at the bottom of the list. When you select Show Related Fieldsthe menu reloads to display related fields. When you select a related field, the menu reloads with the fields of the related table. The following example shows where you are in the dot-walk. Each selected reference is stored at the top of the fields menu, and the number of dots preceding the field label indicate how many dots from the initial record the user has reached.
The related fields can be removed by selecting Remove Related Fields at the bottom of the list. To see which fields are reference fields and can be dot-walked, look for green fields with a plus symbol. Once a reference field is highlighted, the expand icon appears above the add icon.
Selecting the expand icon opens the list of fields from the related list in the Available pane. The following example shows that the Assigned to fields were selected. The previous lists of fields appear at the top of the list. Once the field is added to the Selected pane, it appears with its full dot-walked syntax.The most common and fundamental scripting used in ServiceNow is GlideRecord.
Alter and reuse these scripts found in this post for your ServiceNow implementation. Important Note: Always run GlideRecord statements in a development instance first and make sure they work correctly before using in production! GlideRecord - Global. Using GlideRecord to Query Tables. This will return multiple records, because a while statement is used to cycle through the query results. This will return one record, because a if statement is used to cycle through the query results.
This is good if you just want to find one record, however the query would have returned seven items, which isn't completely efficent. The setLimit statement helps performance, because only one record is returned with the query. Using an encoded query is often easier than multiple addQuery lines. You can also use Copy Query to help figure out your encoded query content which is helpful. I prefer to use an encoded query instead of this, but there are situations where this is easier.
If you are doing an update statement in your script, it is good to be extra careful. Comment out your update statement and add a log statement to check the script for accuracy before actually using it.
Here is an example on how to avoid this:. If you are doing an delete statement in your script, it is good to be extra careful. Comment out your delete statement and add a log statement to check the script for accuracy before actually using it.
You can use similar GildeRecord scripts on the client side, except you should enclose them in a GlideAjax Query. In the example below, it uses a Script Include and Client Script to set the Department field on a form based on the Requested For user. SNEClientUtil' ; ga.