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<?xml-stylesheet type="text/xsl" href="https://community.appian.com/cfs-file/__key/system/syndication/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/"><channel><title>Is there a way to make parameters on an expression rule optional?...</title><link>https://community.appian.com/discussions/f/rules/173/is-there-a-way-to-make-parameters-on-an-expression-rule-optional</link><description>Is there a way to make parameters on an expression rule optional?... OriginalPostID-35469 OriginalPostID-35469</description><dc:language>en-US</dc:language><generator>Telligent Community 12</generator><item><title>RE: Is there a way to make parameters on an expression rule optional?...</title><link>https://community.appian.com/thread/56808?ContentTypeID=1</link><pubDate>Mon, 18 Jun 2018 18:01:35 GMT</pubDate><guid isPermaLink="false">d3a83456-d57b-489c-a84c-4e8267bb592a:5a9b1cfc-1a4a-4205-94c2-edc3766013c1</guid><dc:creator>PhilB</dc:creator><description>&lt;a href="/members/miguelg220"&gt;Miguel Garcia-Gonzalez&lt;/a&gt; This thread is from June 2012...!&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Is there a way to make parameters on an expression rule optional?...</title><link>https://community.appian.com/thread/56803?ContentTypeID=1</link><pubDate>Mon, 18 Jun 2018 15:21:40 GMT</pubDate><guid isPermaLink="false">d3a83456-d57b-489c-a84c-4e8267bb592a:ec13d5f3-1382-464c-9b0a-d34c44e1a1a3</guid><dc:creator>davel001150</dc:creator><description>if myRule is a function with parameters: parameter1, parameter 2, and parameter3&lt;br /&gt;
&lt;br /&gt;
the following code:&lt;br /&gt;
&lt;br /&gt;
rule!myRule(&lt;br /&gt;
parameter1: local!something&lt;br /&gt;
)&lt;br /&gt;
&lt;br /&gt;
works just fine.  Strangely,&lt;br /&gt;
&lt;br /&gt;
rule!myRule(&lt;br /&gt;
parameter1: local!something,&lt;br /&gt;
parameterIJustMadeUp: local!somethingElse,&lt;br /&gt;
)&lt;br /&gt;
&lt;br /&gt;
also happens to work just fine.  It ignores what you don&amp;#39;t send.  It ignores what you do send that it doesn&amp;#39;t recognize, and doesn&amp;#39;t even give you a warning.  If you happen to misspell one of your keywords it can be ages to find the error.&lt;br /&gt;
&lt;br /&gt;
You do have to send at least one of the parameters by keyword.&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Is there a way to make parameters on an expression rule optional?...</title><link>https://community.appian.com/thread/56586?ContentTypeID=1</link><pubDate>Thu, 14 Jun 2018 05:53:46 GMT</pubDate><guid isPermaLink="false">d3a83456-d57b-489c-a84c-4e8267bb592a:841e0422-0db9-48f3-8b25-d065405cd3b7</guid><dc:creator>krishnau3863</dc:creator><description>Hi moritzw,&lt;br /&gt;
&lt;br /&gt;
                      Yes, it is optional to take parameters in expression rule, if you are going to get the data by passing any parameter then it is needful, or else without using the parameters also we directly fetch the whole data from DB.&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Is there a way to make parameters on an expression rule optional?...</title><link>https://community.appian.com/thread/56585?ContentTypeID=1</link><pubDate>Thu, 14 Jun 2018 05:44:22 GMT</pubDate><guid isPermaLink="false">d3a83456-d57b-489c-a84c-4e8267bb592a:ddcadfe0-eeef-409e-ac06-04a831d78bef</guid><dc:creator>gurdeeps</dc:creator><description>Hi, there is no way that an expression&amp;#39;s parameter can be optional, but you can pass the parameter in key value pair (name:ri!name), here you can pass ri!name such that it should not have any impact in the evaluation of the rule.&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Is there a way to make parameters on an expression rule optional?...</title><link>https://community.appian.com/thread/56582?ContentTypeID=1</link><pubDate>Thu, 14 Jun 2018 05:28:49 GMT</pubDate><guid isPermaLink="false">d3a83456-d57b-489c-a84c-4e8267bb592a:e8503236-6923-4703-8698-f585130ce869</guid><dc:creator>Shanmukha</dc:creator><description>Hi Morit,&lt;br /&gt;
&lt;br /&gt;
Could you please why you would like to make parameters as optional?&lt;br /&gt;
Thanks..!!!&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Is there a way to make parameters on an expression rule optional?...</title><link>https://community.appian.com/thread/56580?ContentTypeID=1</link><pubDate>Thu, 14 Jun 2018 05:22:57 GMT</pubDate><guid isPermaLink="false">d3a83456-d57b-489c-a84c-4e8267bb592a:88018c56-3832-4edc-af1d-ece77ef420b4</guid><dc:creator>Abhay Giri</dc:creator><description>Hi Moritzw,&lt;br /&gt;
&lt;br /&gt;
As technically parameters in expression rules are optional always. If you don&amp;#39;t want to pass any parameter value in the rule then simple pass the values by key-value expression.so for the missing key(parameter) it will take value Null as default.&lt;br /&gt;
&lt;br /&gt;
Regards&lt;br /&gt;
Abhay&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Is there a way to make parameters on an expression rule optional?...</title><link>https://community.appian.com/thread/56573?ContentTypeID=1</link><pubDate>Wed, 13 Jun 2018 19:30:34 GMT</pubDate><guid isPermaLink="false">d3a83456-d57b-489c-a84c-4e8267bb592a:6506557d-17c7-44c3-be4a-2a89947e40d2</guid><dc:creator>Ashvin Kapur</dc:creator><description>Parameters on an expression rule are technically always optional - if you use the [parameterName]: to define your parameters, the process/rule will always pass in null for any parameters skipped. As Miguel has stated, there is a requirement to pass in at least one parameter if parameters exist in the expression rule, but if that&amp;#39;s a problem for whatever reason, you can create a dummy variable that does nothing within your rule.&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Is there a way to make parameters on an expression rule optional?...</title><link>https://community.appian.com/thread/56572?ContentTypeID=1</link><pubDate>Wed, 13 Jun 2018 19:04:18 GMT</pubDate><guid isPermaLink="false">d3a83456-d57b-489c-a84c-4e8267bb592a:b076ef57-f3eb-40c9-8314-bcddd3516a26</guid><dc:creator>Miguel Garcia-Gonzalez</dc:creator><description>If you don&amp;#39;t give a parameter a value when you are calling an expression rule the value will be set as null by default, but you still need at least a parameter being passed to avoid an error message asking for those parameters.&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Is there a way to make parameters on an expression rule optional?...&lt;p style='di</title><link>https://community.appian.com/thread/397?ContentTypeID=1</link><pubDate>Tue, 19 Jun 2012 14:19:54 GMT</pubDate><guid isPermaLink="false">d3a83456-d57b-489c-a84c-4e8267bb592a:92ed4fbb-cdf4-48f6-9db3-e10a3659035c</guid><dc:creator>Michael Tan</dc:creator><description>There is no way to do this. The rule will complain if there is not the correct number of parameters passed. If the value is optional in process, then make your rule account for this by checking for null values.&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>