Glide Server APIs

ServiceNow provides APIs for the Glide Server.

GlideAggregate

The GlideAggregate class is an extension of GlideRecord and allows database aggregation (COUNT, SUM, MIN, MAX, AVG) queries to be done. This can be helpful in creating customized reports or in calculations for calculated fields.

주:

This functionality requires a knowledge of JavaScript.

For additional information, refer to GlideAggregate API.

GlideAggregate examples

GlideAggregate is an extension of GlideRecord and its use is probably best shown through a series of examples.

주:

This functionality requires a knowledge of JavaScript.

Here is an example that simply gets a count of the number of records in a table:

var count = new GlideAggregate('incident');
count.addAggregate('COUNT');
count.query();
var incidents = 0;
if(count.next()) 
   incidents = count.getAggregate('COUNT');

There is no query associated with the preceding example. If you want to get a count of the incidents that were open, simply add a query as is done with GlideRecord. Here is an example to get a count of the number of active incidents.

var count = new GlideAggregate('incident');
count.addQuery('active','true');
count.addAggregate('COUNT');
count.query();
var incidents = 0;
if(count.next()) 
   incidents = count.getAggregate('COUNT');

To get a count of all the open incidents by category the code is:

var count = new GlideAggregate('incident');
count.addQuery('active','true');
count.addAggregate('COUNT','category');
count.query();
while(count.next()){
  var category = count.category;
  var categoryCount = count.getAggregate('COUNT','category');
  gs.log("The are currently "+ categoryCount +" incidents with a category of "+ category);}

The output is:

 *** Script: The are currently 1.0 incidents with a category of Data  
       *** Script: The are currently 11.0 incidents with a category of Enhancement
       *** Script: The are currently 1.0 incidents with a category of Implementation
       *** Script: The are currently 197.0 incidents with a category of inquiry
       *** Script: The are currently 13.0 incidents with a category of Issue
       *** Script: The are currently 1.0 incidents with a category of 
       *** Script: The are currently 47.0 incidents with a category of request

The following is an example that uses multiple aggregations to see how many times records have been modified using the MIN, MAX, and AVG values.

var count = new GlideAggregate('incident');
count.addAggregate('MIN','sys_mod_count');
count.addAggregate('MAX','sys_mod_count');
count.addAggregate('AVG','sys_mod_count');
count.groupBy('category');
count.query();
while(count.next()){
  var min = count.getAggregate('MIN','sys_mod_count');
  var max = count.getAggregate('MAX','sys_mod_count');
  var avg = count.getAggregate('AVG','sys_mod_count');
  var category = count.category.getDisplayValue();
  gs.log(category +" Update counts: MIN = "+ min +" MAX = "+ max +" AVG = "+ avg);}

The output is:

       *** Script: Data Import Update counts: MIN = 4.0 MAX = 21.0 AVG = 9.3333
       *** Script: Enhancement Update counts: MIN = 1.0 MAX = 44.0 AVG = 9.6711
       *** Script: Implementation Update counts: MIN = 4.0 MAX = 8.0 AVG = 6.0
       *** Script: inquiry Update counts: MIN = 0.0 MAX = 60.0 AVG = 5.9715
       *** Script: Inquiry / Help Update counts: MIN = 1.0 MAX = 3.0 AVG = 2.0
       *** Script: Issue Update counts: MIN = 0.0 MAX = 63.0 AVG = 14.9459
       *** Script: Monitor Update counts: MIN = 0.0 MAX = 63.0 AVG = 3.6561
       *** Script: request Update counts: MIN = 0.0 MAX = 53.0 AVG = 5.0987

The following is a more complex example that shows how to compare activity from one month to the next.

var agg = new GlideAggregate('incident');
agg.addAggregate('count','category'); 
agg.orderByAggregate('count','category'); 
agg.orderBy('category'); 
agg.addQuery('opened_at','>=','javascript:gs.monthsAgoStart(2)'); 
agg.addQuery('opened_at','<=','javascript:gs.monthsAgoEnd(2)'); 
agg.query();
while(agg.next()){
  var category = agg.category;
  var count = agg.getAggregate('count','category');
  var query = agg.getQuery();
  var agg2 = new GlideAggregate('incident');   
  agg2.addAggregate('count','category');
  agg2.orderByAggregate('count','category');
  agg2.orderBy('category');
  agg2.addQuery('opened_at','>=','javascript:gs.monthsAgoStart(3)');
  agg2.addQuery('opened_at','<=','javascript:gs.monthsAgoEnd(3)');
  agg2.addEncodedQuery(query);
  agg2.query();
  var last ="";
  while(agg2.next()){
     last = agg2.getAggregate('count','category');}
  gs.log(category +": Last month:"+ count +" Previous Month:"+ last);
 
}

The output is:

 *** Script: Monitor: Last month:6866.0 Previous Month:4468.0
 *** Script: inquiry: Last month:142.0 Previous Month:177.0
 *** Script: request: Last month:105.0 Previous Month:26.0
 *** Script: Issue: Last month:8.0 Previous Month:7.0
 *** Script: Enhancement: Last month:5.0 Previous Month:5.0
 *** Script: Implementation: Last month:1.0 Previous Month:0

The following is an example to obtain distinct count of a field on a group query.

var agg = new GlideAggregate('incident');
agg.addAggregate('count');
agg.addAggregate('count(distinct','category');
agg.addQuery('opened_at', '>=', 'javascript:gs.monthsAgoStart(2)');
agg.addQuery('opened_at', '<=', 'javascript:gs.monthsAgoEnd(2)');
//
agg.groupBy('priority');
agg.query();
while (agg.next()) {
// Expected count of incidents and count of categories within each priority value (group)
  gs.info('Incidents in priority ' + agg.priority + ' = ' + agg.getAggregate('count') + 
            ' (' + agg.getAggregate('count(distinct','category') + ' categories)');
}

The output is:

*** Script: Incidents in priority 1 = 13 (3 categories)
*** Script: Incidents in priority 2 = 10 (5 categories)
*** Script: Incidents in priority 3 = 5 (3 categories)
*** Script: Incidents in priority 4 = 22 (6 categories)

You can implement the SUM aggregate with or without the use of the groupBy() method. If you do not use the groupBy() method, the result of the SUM is the cumulative value for each different value of the field for which you request the SUM. For example, if you SUM the total_cost field in the Fixed Asset table, and the Fixed Asset table contains 12 total records:

• Three records with a total_cost of $12
• Four records with a total_cost of $10
• Five records with a total_cost of $5

When you SUM the record set, the getAggregate() method returns three different sums: $36, $40, and $25.

The following code illustrates implementing the SUM aggregate without using the groupBy() method:

var totalCostSum = new GlideAggregate('fixed_asset');
totalCostSum.addAggregate('SUM', 'total_cost');
totalCostSum.query();
 
while (totalCostSum.next()) {
  var allTotalCost = 0;
  allTotalCost = totalCostSum.getAggregate('SUM', 'total_cost');
  aTotalCost = totalCostSum.getValue('total_cost');
  gs.print('Unique field value: ' + aTotalCost + ', SUM = ' + allTotalCost + ', ' + allTotalCost/aTotalCost + ' records');
}

The output for this example is:

*** Script: Unique field value: 12, SUM = 36, 3 records
*** Script: Unique field value: 10, SUM = 40, 4 records
*** Script: Unique field value: 5, SUM = 25, 5 records

Using the same data points as the prior example, if you use the groupBy() method, the SUM aggregate returns the sum of all values for the specified field.

The following example illustrates implementing the SUM aggregate using the groupBy() method:

var totalCostSum = new GlideAggregate('fixed_asset');
totalCostSum.addAggregate('SUM', 'total_cost');
totalCostSum.groupBy('total_cost');
totalCostSum.query();
if(totalCostSum.next()){  // in case there is no result
   var allTotalCost = 0;
   allTotalCost = totalCostSum.getAggregate('SUM', 'total_cost');
   gs.print('SUM of total_cost: = ' + allTotalCost);
}

The output for this example is:

*** Script: SUM of total_cost: 101

GlideRecord

GlideRecord is a special Java class (GlideRecord.java) that can be used in JavaScript exactly as if it was a native JavaScript class.

GlideRecord:

• is used for database operations instead of writing SQL queries.
• is an object that contains zero or more records from one table. Another way to say this is that a GlideRecord is an ordered list.

A GlideRecord contains both records (rows) and fields (columns). The field names are the same as the underlying database column names. For additional information, refer to GlideRecord - Scoped.

주:

Use of gs.sql()) scripting syntax was discontinued in Geneva. Use standard GlideRecord syntax in its place.

Using GlideRecordSecure

GlideRecordSecure is a class inherited from GlideRecord that performs the same functions as GlideRecord, and also enforces ACLs.

Non-writable fields

Be aware that, when using GlideRecordSecure, non-writable fields are set to NULL when trying to write to the database. By default, canCreate() on the column is replaced with canWrite() on the column. If that returns false, the column value is set to NULL.

Getting the object type

You can check if an object type is ScopedGlideRecordSecure by calling the toString() method.

Checking the returned GlideRecord real type

The current object can be passed as ScopedGlideRecordSecure. In most cases, you can call current.toString() to return the current object type.

The following line returns [object ScopedGlideRecordSecure] for a ScopedGlideRecordSecure object:

gs.info(current.toString());

If the returned object type is different than expected

Calling a scoped function that returns a GlideRecord object as its type returns different results depending on the scope it’s called from.

• Calling the scoped function within application scope returns the expected object type of GlideRecord or GlideRecordSecure.
• Calling the scoped function within global scope returns the object type is ScopedGlideRecord or ScopedGlideRecordSecure.

Checking for NULL values

If an element cannot be read because an ACL restricts access, a NULL value is created in memory for that record. With GlideRecord, you must explicitly check for any ACLs that might restrict read access to the record. To do so, an if statement such as the following is required to check if the record can be read:

if ( !grs.canRead() ) continue;

With GlideRecordSecure, you do not need to explicitly check for read access using canRead(). Instead, you can use next() by itself to move to the next record. The following example provides a comparison between GlideRecord and GlideRecordSecure.

var count  = 0;
var now_GR  = new GlideRecord('mytable');
now_GR. query(); 
while (now_GR. next()) { 
    if (!now_GR. canRead()) continue; 
    if (!now_GR. canWrite()) continue; 
    if (!now_GR. val. canRead() || !now_GR. val. canWrite())
        now_GR. val = null;
    else
        now_GR. val = "val-" + now_GR. id; 
    if (now_GR. update())
        count ++; 
}

var count  = 0; 
var grs  = new GlideRecordSecure('mytable');
grs. query(); 
while (grs. next()) {
    grs. val = "val-" + grs. id; 
    if (grs. update())
        count ++; 
}

Examples

These are two simple examples using GlideRecordSecure.

var att  = new GlideRecordSecure('sys_attachment');
att. get('$[sys_attachment.sys_id]'); 
var sm  = GlideSecurityManager.get(); 
var checkMe  = 'record/sys_attachment/delete'; 
var canDelete  = sm.hasRightsTo(checkMe,att);
gs. log('canDelete: ' + canDelete);
canDelete;

var grs = new GlideRecordSecure('task_ci');
grs.addQuery();
grs.query(); 
var count  = grs. getRowCount(); 
if (count  > 0 ) { 
    var allocation  = parseInt(10000/count) / 100;
    while (grs.next()) {
      grs.u_allocation = allocation;
      grs.update();
    }
}

GlideSystem

The GlideSystem API provides methods for retrieving information.

The GlideSystem (referred to by the variable name 'gs' in business rules) provides a number of convenient methods to get information about the system, the current logged in user, etc. For example, the method addInfoMessage() permits communication with the user.

 gs.addInfoMessage('Email address added for notification');

Many of the GlideSystem methods facilitate the easy inclusion of dates in query ranges and are most often used in filters and reporting.

For additional information, see GlideSystem.

GlideDateTime

The GlideDateTime class provides methods for performing operations on GlideDateTime objects, such as instantiating GlideDateTime objects or working with glide_date_time fields.

In addition to the instantiation methods described below, a GlideDateTime object can be instantiated from a glide_date_time field using the getGlideObject() method (for example, var gdt = gr.my_datetime_field.getGlideObject();).

Some methods use the Java Virtual Machine time zone when retrieving or modifying a date and time value. Using these methods may result in unexpected behavior. Use equivalent local time and UTC methods whenever possible.

GlideDate and GlideDateTime examples

The GlideDate and GlideDateTime APIs are used to manipulate date and time values.

주:

This functionality requires a knowledge of JavaScript.

For additional information, refer to GlideDate API and GlideDateTime API.

You can create a GlideDateTime object from a GlideDate object by passing in the GlideDate object as a parameter to the GlideDateTime constructor. By default, the GlideDateTime object is expressed in the internal format, yyyy-MM-dd HH:mm:ss and the system time zone UTC.

var gDate = new GlideDate();
gDate.setValue('2015-01-01');
gs.info(gDate);
 
var gDT = new GlideDateTime(gDate);
gs.info(gDT);

Output:

2015-01-01
2015-01-01 00:00:00

See also Modify a GlideDateTime field value.

Set a duration field value in script

Examples of JavaScript that can be used to set the value of a duration field.

주:

Negative duration values are not supported.

Using the GlideDateTime.subtract() method

The subtract(GlideDateTime start, GlideDateTime end) method in GlideDateTime enables you to set the duration value using a given start date/time and end date/time. An example on how to set the duration for the time a task was opened is:

var duration = GlideDateTime.subtract(start, end);

If you want to work with the value returned as a number to use in date or duration arithmetic, convert the return to milliseconds:

var time = GlideDateTime.subtract(start,end).getNumericValue();

If you want to set a duration to the amount of time between some event and the current date/time:

<duration_field> = GlideDateTime.subtract(new GlideDateTime(<start_time>.getValue()),gs.nowDateTime());

The time values presented to GlideDateTime.subtract are expected to be in the user's time zone and in the user's format.

Setting a default value of a duration field

Setting the default value for a duration field is similar to the method used in the previous topic.

Setting the duration field value in a client script

This script sets a duration_field value in a client script. Replace duration_field with the field name from your instance.

g_form.setValue('<duration_field>','11 01:02:03');

Calculating and setting a duration using a client script

Here is an example of how to return a value and populate it using a client script.

Create an onChange client script that includes the following code. You can modify this script if you need the calculation to happen in an onLoad script or some other way.

function onChange(control, oldValue, newValue, isLoading){
var strt = g_form.getValue('<start_field>');
var end = g_form.getValue('<end_field>');
var ajax = new GlideAjax('AjaxDurCalc');
  ajax.addParam('sysparm_name','durCalc');
  ajax.addParam('sysparm_strt',strt);
  ajax.addParam('sysparm_end',end);
  ajax.getXMLWait();
  var answer = ajax.getAnswer();
  g_form.setValue('<duration_field>', answer);}

Create a system script include file called AjaxDurCalc that handles the request. It may be reused for other functions as well.

var AjaxDurCalc = Class.create();
AjaxDurCalc.prototype = Object.extendsObject(AbstractAjaxProcessor,{
 durCalc:function(){return GlideDuration.subtract(this.getParameter('sysparm_strt'),this.getParameter('sysparm_end'));}});

Changing the duration field value

If you manipulate a duration value with addition/subtraction of some amount of time, use the functions that allow you to get and set the numeric value of the duration. A unit of measure for a duration numeric value is milliseconds. The following is an example that adds 11 seconds to the duration field in the current record.

var timems = current.duration.dateNumericValue();
timems = timems + 11*1000; 
current.duration.setDateNumericValue(timems);

Formatting the Resolve Time

To format the Resolve Time or the Business Resolve Time fields as durations, which displays them as a duration instead of a large integer, add the following attribute to those fields:

format=glide_duration

Modify the dictionary entry for the field and add the attribute. If there is an existing attribute, separate multiple attributes with commas.

Setting the maximum unit of measurement

The max_unit dictionary attribute defines the maximum unit of time used in a duration. For example, if max_unit=minutes, a duration of 3 hours 5 minutes 15 seconds appears as 185 minutes 15 seconds. To set the maximum unit of duration measurement, add the following dictionary attribute to the duration field:

max_unit=<unit>

Date and time format guidelines

You can specify a date format with a sequence of specific date and time pattern strings. A pattern string consists of one or more uppercase and lowercase letters from A to Z. Any text within quotation marks is ignored and is instead copied into the date output.

String	Description	Output Format	Example
G	Era designator	Text	AD
y	Year	Year	2019; 19
Y	Week in year	Year	2019; 19
M	Month in year (within date)	Month	July; Jul; 07
L	Month in year (standalone value)	Month	July; Jul; 07
w	Week in year	Number	52
W	Week in month	Number	1
D	Day in year	Number	365
d	Day in month	Number	2
F	Day of week in month	Number	3
E	Day name in week	Text	Wednesday; Wed
u	Day number of week	Number	3
a	a.m. or p.m.	Text	p.m.
H	Hour in day from 0 through 23	Number	0
k	Hour in day from 1 through 24	Number	24
K	Hour in a.m. or p.m. from 0 through 11	Number	0
h	Hour in a.m. or p.m. from 1 through 12	Number	12
m	Minute in hour	Number	59
s	Second in minute	Number	1
S	Millisecond	Number	500
z	Time zone in default format	Time zone in default format	Pacific Standard Time; PST
Z	Time zone in RFC 822 format	Time zone in RFC 822 format	-0800
X	Time zone in ISO 8601 format	Time zone in ISO 8601 format	-08; -0800; -08:00