Setting the URL property of a field in a data grid turns the display value into a link to other content. The URL property setting is the target address of the link. The URL property supports different options for defining relative or absolute links, and also supports using values from other fields in constructing the URL.

Link Format Types

Several link format types for URL property are supported: local, relative, and full path links on the server as well as external links. Learn more about the context, controller, action, and path elements of LabKey URLs in this topic: LabKey URLs.

Local Links

To link to content in the current LabKey folder, use the controller and action name, but no path information.

<controller>-<action>

For example, to view a page in a local wiki:

wiki-page.view?name=${PageName}

A key advantage of this format is that the list or query containing the URL property can be moved or copied to another folder with the target wiki page, in this case, and it will still continue to work correctly.

You can optionally prepend a / (slash) or ./ (dot-slash), but they are not necessary. You could also choose to format with the controller and action separated by a / (slash). The following format is equivalent to the above:

./wiki/page.view?name=${PageName}

Relative Links

To point to resources in subfolders of the current folder, prepend the local link format with path information, using the . (dot) for the current location:

./<subfoldername/><controller>-<action>

For example, to link to a page in a subfolder, use:

./${SubFolder}/wiki-page.view?name=${PageName}

You can also use .. (two dots) to link to the parent folder, enabling path syntax like "../siblingfolder/resource to refer to a sibling folder. Use caution when creating complex relative URL paths as it makes references more difficult to follow in the case of moving resources. Consider a full path to be more clear when linking to a distant location.

Full Path Links on the Same Server

A full path link points to a resource on the current LabKey Server, useful for:

  • linking commmon resources in shared team folders
  • when the URL is a WebDAV link to a file that has been uploaded to the current server
The local path begins with a / (forward slash).

For example, if a page is in a subfolder of "myresources" under the home folder, the path might be:

/home/myresources/subfolder/wiki-page.view?name=${Name}

External Links

To link to a resource on an external server or any website, include the full URL link. If the external location is another labkey server, the same path, controller, and action path information will apply:

http://server/path/page.html?id=${Param}

Substitution Syntax

If you would like to have a data grid contain a link including an element from elsewhere in the row, the ${ } substitution syntax may be used. This syntax inserts a named field's value into the URL. For example, in a set of experimental data where one column contains a Gene Symbol, a researcher might wish to quickly compare her results with the information in The Gene Ontology. Generating a URL for the GO website with the Gene Symbol as a parameter will give the researcher an efficient way to "click through" from any row to the correct gene.

An example URL (in this case for the BRCA gene) might look like:

http://amigo.geneontology.org/amigo/search/ontology?q=brca

Since the search_query parameter value is the only part of the URL that changes in each row of the table, the researcher can set the URL property on the GeneSymbol field to use a substitution marker like this:

http://amigo.geneontology.org/amigo/search/ontology?q=${GeneSymbol}

Once defined, the researcher would simply click on "BRCA" in the correct column to be linked to the URL with the search_query parameter applied.

Multiple such substitution markers can be used in a single URL property string, and the field referenced by the markers can be any field within the query.

Substitutions are allowed in any part of the URL, either in the main path, or in the query string. For example, here are two different formats for creating links to an article in wikipedia, here using a "CompanyName" field value:

  • as part of the path:
  • as a parameter value:

Built-in Substitution Markers

The following substitutions markers are built-in and available for any query/dataset. They help you determine the context of the current query.

MarkerDescriptionExample Value
${schemaName}The schema where the current query lives.study
${schemaPath}The schema path of the current query.assay.General.MyAssayDesign
${queryName}The name of the current queryPhysical Exam
${dataRegionName}The data region for the current query.Dataset
${containerPath}The LabKey Server folder path, starting with the project/home/myfolderpath
${contextPath}The Tomcat context path/labkey
${selectionKey}Unique string used by selection APIs as a key when storing or retrieving the selected items for a grid$study$Physical Exam$$Dataset

Link Display Text

The display text of the link created from a URL property is just the value of the current record in the field which contains the URL property. So in the Gene Ontology example, since the URL property is defined on the Gene_Symbol field, the gene symbol serves as both the text of the link and the value of the search_query parameter in the link address. In many cases you may want to have a constant display text for the link on every row. This text could indicate where the link goes, which would be especially useful if you want multiple such links on each row.

In the example above, suppose the researcher wants to be able to look up the gene symbol in both Gene Ontology and EntrezGene. Rather than defining the URL Property on the Gene_Symbol field itself, it would be easier to understand if two new fields were added to the query, with the value in the fields being the same for every record, namely "[GO]" and "[Entrez]". Then set the URL property on these two new fields to

for the GOlink field:

http://amigo.geneontology.org/cgi-bin/amigo/search.cgi?search_query=${Gene_Symbol}&action=new-search

for the Entrezlink field:

http://www.ncbi.nlm.nih.gov/gene/?term=${Gene_Symbol}

The resulting query grid will look like:

Note that if the two new columns are added to the underlying list, dataset, or schema table directly, the link text values would need to be entered for every existing record. Changing the link text would also be tedious. A better approach is to wrap the list in a query that adds the two fields as constant expressions. For this example, the query might look like:

SELECT TestResults.SampleID,
TestResults.TestRun,
TestResults.Gene_Symbol,
TestResults.ResultValueN,

'[GO]' AS GOlink,
'[Entrez]' AS Entrezlink

FROM TestResults

Then in the Edit Metadata page of the Schema Browser, set the URL properties on these query expression fields:

URL Encoding Options

You can specify the type of URL encoding for a substitution marker, in case the default behavior doesn't work for the URLs needed. This flexibility makes it possible to have one column display the text and a second column can contain the entire href value, or only a part of the href. The fields referenced by the ${ } substitution markers might contain any sort of text, including special characters such as question marks, equal signs, and ampersands. If these values are copied straight into the link address, the resulting address would be interpreted incorrectly. To avoid this problem, LabKey Server encodes text values before copying them into the URL. In encoding, characters such as ? are replaced by their character code %3F. By default, LabKey encodes all special character values except '/' from substitution markers. If you know that a field referenced by a substitution marker needs no encoding (because it has already been encoded, perhaps) or needs different encoding rules, inside the ${ } syntax, you can specify encoding options as described in the topic String Expression Format Functions.

Links Without the URL Property

If the data field value contains an entire url starting with an address type designator (http:, https:, etc), then the field value is displayed as a link with the entire value as both the address and the display text. This special case could be useful for queries where the query author could create a URL as an expression column. There is no control over the display text when creating URLs this way, however.

Linking To Other Tables

To link two tables, so that records in one table link to filtered views of the other, start with a filtered grid view of the target table, filtering on the target fields of interest. For example, the following URL filters on the fields "WellLocation" and "WellType":

/home/demo%20study/study-dataset.view?datasetId=5018&Dataset.WellLocation~eq=AA&Dataset.WellType~eq=XX

Parameterize by adding substitution markers within the filter. For example, assume that source and target tables have identical field names, "WellLocation" and "WellType":

/home/demo%20study/study-dataset.view?datasetId=5018&Dataset.WellLocation~eq=${WellLocation}&Dataset.WellType~eq=${WellType}

Finally, set the parameterized URL as the URL property of the appropriate column in the source table.

Related Topics

For an example of UI usage, see: Step 3: Add a URL Property and view an interactive example by clicking here. Hover over a link in the Species column to see the URL, click to view a list filtered to display only demographic data for the specific species.

For examples of SQL metadata XML usage, see: JavaScript API Demo Summary Report and the JavaScript API Tutorial.

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