Direct web services

A direct web service is available for any table in the system if the correct access control list is configured.

The supported format of the incoming message is document style literal XML SOAP documents (Document/Literal). To retrieve a direct web service WSDL description and XML schema, point to the relative URL <tablename>.do?WSDL. For example, to retrieve the WSDL for the Incident table on the online demo system, use the following URL: https://<instance name>.service-now.com/incident.do?WSDL.

Extended query parameters

Extended query parameters enable you to filter and modify the return results of a SOAP query when using the get, getKeys, and getRecords functions.

Remarque :

Extended query element names are preceded by two underscore characters.

Tableau 1. Available extended query parameters

Parameter	Description	Example
__encoded_query	Specify an encoded query string to be used in filtering the returned results. The encoded query string format is similar to the value that may be specified in a sysparm_query URL parameter. See the encoded query building example in the RSS feed generator examples.	<__encoded_query>active=true^category='hardware'</__encoded_query>
__order_by	Instruct the returned results to be ordered by the specified field.	<__order_by>priority</__order_by>
__order_by_desc	Instruct the returned results to be ordered by the specified field, in descending order.	<__order_by_desc>opened_date</__order_by_desc>
__exclude_columns	Specify a list of comma delimited field names to exclude from the result set.	<__exclude_columns>sys_created_on,sys_created_by,caller_id,priority</__exclude_columns>
__limit	Limit the number of records that are returned.	<__limit>100</__limit>
__first_row	Instruct the results to be offset by this number of records from the beginning of the set. When used with __last_row has the effect of querying for a window of results. The results are inclusive of the first row number.	<__first_row>250</__first_row>
__last_row	Instruct the results to be limited by this number of records from the beginning of the set, or the __start_row value when specified. When used with __first_row has the effect of querying for a window of results. The results are less than the last row number, and does not include the last row.	<__last_row>500</__last_row>
__use_view	Specify a Form view by name, to be used for limiting and expanding the results returned. When the form view contains deep referenced fields such as caller_id.email, this field will be returned in the result as well.	<__use_view>soap_view</__use_view>

Direct web services namespace

Specifying a unique namespace for each table

The glide.wsdl.definition.use_unique_namespace property ensures that each table's direct web service WSDL has a unique targetNamespace attribute. This property is true by default, which requires a table's direct web service WSDL to use a targetNamespace value of http://www.service-now.com/<table name>. When false (or when the property is not present), all tables use the same targetNamespace value of http://www.service-now.com. Since all tables also share the same operation names, a web service client attempting to consume more than one ServiceNow web service would be unable to differentiate between requests between multiple tables. Using a unique targetNamespace value allows web service clients to distinguish requests between multiple tables.

For example, the direct web service WSDL for the incident table uses this targetNamepsace value:

<wsdl:definitions xmlns:soapenc= "http://schemas.xmlsoap.org/soap/encoding/"xmlns:wsdl = "http://schemas.xmlsoap.org/wsdl/"xmlns:http = "http://schemas.xmlsoap.org/wsdl/http/"xmlns:tns = "http://www.service-now.com/incident"xmlns:xsd = "http://www.w3.org/2001/XMLSchema"xmlns:mime = "http://schemas.xmlsoap.org/wsdl/mime/"xmlns:soap = "http://schemas.xmlsoap.org/wsdl/soap/"targetNamespace = "http://www.service-now.com/incident" ><wsdl:types><xsd:schema elementFormDefault = "unqualified"targetNamespace = "http://www.service-now.com/incident" >

Setting namespace requirements

ServiceNow's WSDL schema by default declares an attribute of elementFormDefault="unqualified". This attribute indicates whether or not locally declared elements must be qualified by the targetNamepsace in an instance document. If the value of this attribute is unqualified, then locally declared elements should not be qualified by the targetNamepsace. If the value of this attribute is qualified, then locally declared elements must be qualified by the targetNamepsace.

However, this is incompatible with the way clients generated from WSDL (for example, .NET, Axis2, webMethods) process the embedded schema. It removes the schema namespace as a result, making the web service response unparseable.

To overcome this compatibility issue, a boolean property called glide.wsdl.schema.UnqualifiedElementFormDefault is introduced. This property has the value of true by default. Setting it to false enables clients generated from WSDL to parse the return value of the web service invocation. You can modify this property using the Web Services properties page at System Properties > Web Services.

Allowing duplicate service names

By default, service names from dynamically generated WSDL are unique and have the following format:

ServiceNow_<table name>

To allow duplicate service names, administrators can set the glide.wsdl.unique_service_name property to false. Create the property if it does not exist.

• Use forms to limit or extend the query response
  On occasion, there is a need to limit the number of field values that a SOAP query returns.
• Return the display value for reference variables
  When you query a record using a get or getRecords function, the instance returns all fields associated with that record. The fields are often reference fields that contain a sys_id for a record on another table.
• Clear values from a target instance
  You can pass an empty value through a SOAP parameter to clear the respective value in the target instance.
• Retrieve journal entries using direct web services
  To get the contents of a journal field, make a second soap request against the sys_journal_field table to pull the appropriate journal records back for the record in question.
• Retrieve choice fields using direct web services
  To retrieve or set choice fields, use the choice Value, not the Label.
• Persist an HTTP session across all SOAP calls
  In circumstances when a SOAP client makes many calls in a short amount of time, you may want to re-use a single HTTP session for all SOAP calls.
• SOAP direct web service API functions
  The standard SOAP API is a set of small, globally defined functions that can be performed on a targeted resource.

Concepts associés

• SOAP web service