Skip to main content

Function Support for Queries in OData Extension

Image
By
In a previous post I was talking about the URL Syntax for OData Query Extension. In the current installment, I will present an enhancement to the URL $filter option parser that will allow us to use custom functions. These functions will give us even more possibilities to specify Criterias in RESTful URLs.

The new version is available as JAR distributable (odata-query-extension-1.2.jar) and also as source code.

One of the limitations in the previous OData Query Extension parser was the inability to specify the CustomMetaValue and CustomMetaKey criteria, as they pretty much need to appear nested in one-another:

CustomMetaValue(CustomMetaKey(theKey), theValue[, operator])

Another tricky point are the criterias that accept several parameters, such as

TaxonomyKeywordName(publicationId, taxonomyId, keywordName, includeBranches, operator)

Therefore, I enhanced the parser logic to allow functions in the following syntax:

function(parameter [, field_operator] [, parameter [, field_operator] ]

,where
  • function - a predefined name corresponding to one of the criterias described further down in this post;
  • parameter - a string, number, boolean or 'function name' denoting the value corresponding to a parameter in the function's arguments;
  • field_operator - optional FieldOperator to apply to the previous parameter. Can be one of eq, neq, gt, ge, lt, le, like.
The additional LL(1) grammar rules are:

and_term -> FUNCTION func_op
and_term -> argument
field_op -> FIELD_OPERATOR value
func_op -> OPEN_BRACKET parameter CLOSE_BRACKET

 parameter -> FUNCTION func_op param_op
parameter -> value param_op

 param_op -> SEPARATOR FIELD_OPERATOR param_op
param_op -> SEPARATOR parameter
param_op -> EPSILON

Using the new enhanced parser, I implemented the following functions:

CustomMetaKey

CustomMetaKey(keyName[, field_operator])

Specifies a CustomMetaKeyCriteria for a given custom meta key field, optionally with a field_operator.

Example: CustomMetaKey('doc%', like)

CustomMetaValue

CustomMetaValue(CustomMetaKey(keyName), value[, field_operator])

Specifies a combined CustomMetaKey / CustomMetaValue criteria where the keyName and value belong to the same item's custom meta.
The value can be one of string, float or date (for date, expected format is yyyy-MM-dd HH:mm:ss.SSS)

Example: CustomMetaValue(CustomMetaKey('color'), 'red')

CustomMetaDateRange

CustomMetaDateRange(beginRange, endRange)
CustomMetaDateRange(beginRange, endRange, includeRange)
CustomMetaDateRange(metaFieldName, beginRange, endRange, includeRange)

Specifies a date range for a metadata field. If metadataFieldName is specified, the date range criteria is applied to this field, otherwise to any field of type date. Date format is yyyy-MM-dd HH:mm:ss.SSS

Example: CustomMetaDateRange('expiredate', '2012-10-01 12:00:00.000', '2013-03-15 12:00:00.000', false)

CustomMetaStringRange

CustomMetaStringRange(beginRange, endRange)
CustomMetaStringRange(beginRange, endRange, includeRange)
CustomMetaStringRange(metaFieldName, beginRange, endRange, includeRange)

Specifies a string range for a metadata field. If metadataFieldName is specified, the string range criteria is applied to this field, otherwise to any field of type string.

Example: CustomMetaStringRange('author', 'Adam', 'John', false)

NumericalRange

NumericalRange(beginRange, endRange)
NumericalRange(beginRange, endRange, includeRange)
NumericalRange(metaFieldName, beginRange, endRange, includeRange)

Specifies a numeric range for a metadata field. If metadataFieldName is specified, the numeric range criteria is applied to this field, otherwise to any field of type numeric.

Example: NumericalRange('price', 1.25, 9.99, false)

StructureGroup

StructureGroup(sgUri)
StructureGroup(sgUri, includeChildSGs)

Specifies a Structure Group such that returned results are only Pages within that Structure Group. By specifying includeChildSGs boolean, it is possible to restrict results to an explicit SG or to an entire branch.

Example: StructureGroup('tcm:3-12-4', true)

StructureGroupDirectory

StructureGroupDirectory(directory)
StructureGroupDirectory(directory, field_operator)
StructureGroupDirectory(directory, field_operator, includeChildSGs)

Specifies a criteria such that returned Pages are only within a Structure Group whose property directory matches parameter directory. By specifying includeChildSGs boolean, it is possible to restrict results to the top matched SG or to the whole branch.

Example: StructureGroupDirectory('product%', like, true)

StructureGroupTitle

StructureGroupTitle(title)
StructureGroupTitle(title, field_operator)
StructureGroupTitle(title, field_operator, includeChildSGs)

Specifies a criteria such that returned Pages are only within a Structure Group whose title matches parameter title. By specifying includeChildSGs boolean, it is possible to restrict results to the top matched SG or to the whole branch.

Example: StructureGroupTitle('010 Home', eq, false)

TaxonomyKeyword

TaxonomyKeyword(taxonomyUri, keywordUri, includeKeywordBranches)
TaxonomyKeyword(publicationId, taxonomyId, keywordId, includeKeywordBranches)

Specifies a criteria that returns items classified against a keyword in a taxonomy, and where search is performed on the keyword id.

Example: TaxonomyKeyword(1, 3, 5, false)

TaxonomyKeywordDescription

TaxonomyKeywordDescription(publicationId, taxonomyId, keywordDescription[, field_operator], includeKeywordBranches)

Specifies a criteria that returns items classified against a keyword in a taxonomy, and where search is performed on the keyword description field.

Example: TaxonomyKeywordDescription(1, 3, 'Result%', like, false)

TaxonomyKeywordKey

TaxonomyKeywordKey(publicationId, taxonomyId, keywordKey[, field_operator], includeKeywordBranches)

Specifies a criteria that returns items classified against a keyword in a taxonomy, and where search is performed on the keyword key field.

Example: TaxonomyKeywordKey(1, 3, 'Result Q1', false)

TaxonomyKeywordName

TaxonomyKeywordName(publicationId, taxonomyId, keywordName[, field_operator], includeKeywordBranches)

Specifies a criteria that returns items classified against a keyword in a taxonomy, and where search is performed on the keyword name (a.k.a. title).

Example: TaxonomyKeywordName(1, 3, 'Press%', like, true)


Labels:

Comments

Post a Comment

Popular posts from this blog

Scaling Policies

By
This post is part of a bigger topic Autoscaling Publishers in AWS . In a previous post we talked about the Auto Scaling Groups , but we didn't go into details on the Scaling Policies. This is the purpose of this blog post. As defined earlier, the Scaling Policies define the rules according to which the group size is increased or decreased. These rules are based on instance metrics (e.g. CPU), CloudWatch custom metrics, or even CloudWatch alarms and their states and values. We defined a Scaling Policy with Steps, called 'increase_group_size', which is triggered first by the CloudWatch Alarm 'Publish_Alarm' defined earlier. Also depending on the size of the monitored CloudWatch custom metric 'Waiting for Publish', the Scaling Policy with Steps can add a difference number of instances to the group. The scaling policy sets the number of instances in group to 1 if there are between 1000 and 2000 items Waiting for Publish in the queue. It also sets the
Post a Comment
Read more

Running sp_updatestats on AWS RDS database

By
Part of the maintenance tasks that I perform on a MSSQL Content Manager database is to run stored procedure sp_updatestats . exec sp_updatestats However, that is not supported on an AWS RDS instance. The error message below indicates that only the sa  account can perform this: Msg 15247 , Level 16 , State 1 , Procedure sp_updatestats, Line 15 [Batch Start Line 0 ] User does not have permission to perform this action. Instead there are several posts that suggest using UPDATE STATISTICS instead: https://dba.stackexchange.com/questions/145982/sp-updatestats-vs-update-statistics I stumbled upon the following post from 2008 (!!!), https://social.msdn.microsoft.com/Forums/sqlserver/en-US/186e3db0-fe37-4c31-b017-8e7c24d19697/spupdatestats-fails-to-run-with-permission-error-under-dbopriveleged-user , which describes a way to wrap the call to sp_updatestats and execute it under a different user: create procedure dbo.sp_updstats with execute as 'dbo' as
1 comment
Read more

Toolkit - Dynamic Content Queries

By
This post if part of a series about the  File System Toolkit  - a custom content delivery API for SDL Tridion. This post presents the Dynamic Content Query capability. The requirements for the Toolkit API are that it should be able to provide CustomMeta queries, pagination, and sorting -- all on the file system, without the use third party tools (database, search engines, indexers, etc). Therefore I had to implement a simple database engine and indexer -- which is described in more detail in post Writing My Own Database Engine . The querying logic does not make use of cache. This means the query logic is executed every time. When models are requested, the models are however retrieved using the ModelFactory and those are cached. Query Class This is the main class for dynamic content queries. It is the entry point into the execution logic of a query. The class takes as parameter a Criterion (presented below) which triggers the execution of query in all sub-criteria of a Criterio
Post a Comment
Read more