Background
Prior to OpenMRS version 1.8, the search widgets were written with dojo which involved writing a separate javascript file where you would have to extended the parent OpenmrsSearch for each Openmrs Object if it were to be searchable in the webapp. The widgets would fetch all hits in one ajax query which would take a while to return all the hits in case there are many making the widgets slow. In 1.8, this was changed by introducing a single and more generic search widget written with jquery, the widget is expected to be faster from a user's stand point in that it fetches just the exact amount of results to display on the first page and then continue to query the server for the rest in the background while updating the table until all results are returned. The reason behind this is that it should take way less time to display the first N results to display on the first page rather waiting for all the hits to be returned in one call in case there are many. The objective is to increase the perceived speed from a user's point of view since they get some results returned in a nick of time even if it isn't all.
How to include a search widget for a domain object in a jsp
This can be relatively simple if the domain objects to search already have the required methods in the API. Currently the required methods have been added for Concepts, Encounters, Patients, Users, Locations, Providers, Drugs and ConceptReferenceTerms. Let's assume you wish to add an encounter search widget to your jsp, add the snippet below to your jsp (you can leave out the javascript and css files that you already have in the parent jsp).
<openmrs:htmlInclude file="/dwr/interface/DWREncounterService.js"/>
<openmrs:htmlInclude file="/scripts/jquery/dataTables/css/dataTables_jui.css"/>
<openmrs:htmlInclude file="/scripts/jquery/dataTables/js/jquery.dataTables.min.js"/>
<openmrs:htmlInclude file="/scripts/jquery-ui/js/openmrsSearch.js" />
<script type="text/javascript">
var lastSearch;
$j(document).ready(function() {
new OpenmrsSearch("findEncounter", true, doEncounterSearch, doSelectionHandler,
[ {fieldName:"personName", header:"Patient Name"},
{fieldName:"encounterType", header:"Encounter Type"},
{fieldName:"formName", header:"Encounter Form"},
{fieldName:"providerName", header:"Encounter Provider"},
{fieldName:"location", header:"Encounter Location"},
{fieldName:"encounterDateString", header:"Encounter Date"}
],
{
searchLabel: '<spring:message code="Encounter.search" javaScriptEscape="true"/>',
searchPlaceholder:'<spring:message code="Encounter.search.placeholder" javaScriptEscape="true"/>'
});
});
//The action to take when the user selects an item from the hits in the widget
function doSelectionHandler(index, data) {
document.location = "encounter.form?encounterId=" + data.encounterId + "&phrase=" + lastSearch;
}
//Contains the logic that fetches the results from the server
function doEncounterSearch(text, resultHandler, getMatchCount, opts) {
lastSearch = text;
DWREncounterService.findCountAndEncounters(text, opts.includeVoided, opts.start, opts.length, getMatchCount, resultHandler);
}
</script>
The first four html includes are required because they contain the necessary scripts used by the widgets and the css file for improved styling via datatables' support for jquery-ui themes so that the widgets match the active theme on the page.
Next thing is to initialize the widget and there are 2 ways to do it, the one used above is the one which delegates to a helper function that takes in 4 arguments. Below is the other way:
$j(document).ready(function() {
$j("#elementId").openmrsSearch({
searchLabel:'<spring:message code="General.search"/>',
searchPlaceholder: '<spring:message code="Encounter.search.placeholder" javaScriptEscape="true"/>',
searchHandler: doSearchHandler,
selectionHandler: doSelectionHandler,
fieldsAndHeaders: [ {fieldName:"personName", header:"Patient Name},
{fieldName:"encounterType", header:"Encounter Type},
{fieldName:"formName", header:"Encounter Form},
{fieldName:"providerName", header:"Encounter Provider},
{fieldName:"location", header:"Encounter Location},
{fieldName:"encounterDateString", header:"Encounter Date}
]
});
});
The arguments passed to the widgets are to used to customize the widget properties, in the example above, 'searchLabel' specifies the label that appears to the left of the search input box, 'searchPlaceHolder' specifies the text to display inside the input box as a place holder, 'searchHandler' specifies the javascript function to be called to fetch the hits from the server, and 'fieldsAndHeaders' specifies the properties of the returned objects to display in the table of results along with their respective column headers, see below for the full list of the widget properties. 'SelectionHandler' specifies the function to be called when the user selects a row in the table, in our example above, we open the encounter form and the encounter to edit becomes the selected one.
'SearchHandler' specifies the function that will get called by the script to fetch results from the server, the function gets called at least once once the search is triggered. The first call is expected to return a map with 2 key-value pairs i.e the expected total count of results and results to display on the first page. Typically, you should have logic on the server that get called by this function via ajax and it is important to make sure it returns the expected map. The keys in the returned map are 'count' and 'objectList' and their values should be the total count of expected results and the results to display on the first page respectively. Any subsequent calls to the search handler after the first call don't require that the count gets returned.
In this example, we call the DWREncounterService.findCountAndEncounters(String, boolean, Integer, Integer, boolean) method and below is how the code could like like:
public Map<String, Object> findCountAndEncounters(String phrase, boolean includeVoided, Integer start, Integer length,
boolean getMatchCount) throws APIException {
//Map to return
Map<String, Object> resultsMap = new HashMap<String, Object>();
Vector<Object> objectList = new Vector<Object>();
try {
EncounterService es = Context.getEncounterService();
int encounterCount = 0;
if (getMatchCount)
encounterCount += es.getCountOfEncounters(phrase, includeVoided);
//If we have any matches, fetch them or if this is not the first ajax call
//for displaying the results on the first page, the getMatchCount is expected to be zero
if (encounterCount > 0 || !getMatchCount)
objectList = findBatchOfEncounters(phrase, includeVoided, start, length);
resultsMap.put("count", encounterCount);
resultsMap.put("objectList", objectList);
}
catch (Exception e) {
objectList.clear();
objectList.add("Error while searching for encounters");
resultsMap.put("count", 0);
resultsMap.put("objectList", objectList);
//you can opt to pass in a new phrase which will tell the core search widget to rerun the
//search but for your new phrase and this will lead to ignoring the results you send back
resultsMap.put("searchAgain", "newphrase");
}
return resultsMap;
}
The implementation of the server side logic should call the API methods that return the count and the appropriate search method that supports paging for the given domain object, in this case they would be EncounterService.getCountOfEncounters(String, boolean) and EncounterService.getEncounters(String, Integer, Integer, boolean). In the DAO layer, it's highly recommended that these methods use the same criteria object and the difference should be that the one that gets the count sets a row count projection while the other should return the actual objects matching the criteria. This implies that the total number of hits fetched when the search is done should always match the value returned by the get Count method otherwise the scripts in the widgets will fail with the assumption that there is either more hits to fetch or some will get left out. For an example implementation of the methods in the DAO layer, you can look at HibernateEncounterDAO.getCountOfEncounters(String, boolean) and HibernateEncounterDAO.getEncounters(String, Integer, Integer, boolean).
Widget properties
- minLength: int (default: 1) The minimum number of characters required to trigger a search, this is ignored if 'doSearchWhenEmpty' is set to true
- searchLabel: string (default: omsgs.searchLabel) The text to be used as the label for the search textbox
- includeVoidedLabel: string (default: omsgs.includeVoided) The text to be used as the label for the 'includeVoided' checkbox
- showIncludeVoided: bool (default: false) - Specifies whether the 'includeVoided' checkbox and label should be displayed
- includeVerboseLabel: string (default: omsgs.includeVerbose) The text to be used as the label for the 'includeVerbose' checkbox
- showIncludeVerbose: bool (default: false) Specifies whether the 'includeVerbose' checkbox and label should be displayed
- searchHandler: function(text, resultHandler, options) (default:null) The function to be called to fetch search results from the server
- resultsHandler: function(results) (default:null) The function to be called
- selectionHandler: function(index, rowData
- fieldsAndHeaders: Array of fieldNames and column header maps
- displayLength: int (default: 10)
- columnWidths: an array of column widths, the length of the array should be equal to the number of columns, should be of the same length as the number of columns
- columnRenderers: array of fnRender(s) for each column, should be of the same length as the number of columns, set a value of null for columns with no renderers
- columnVisibility: array of bVisible values for each column, true/false are the only possible values in the array and should be of the same length as the number of columns
- initialData: (default: null) The initial data to be displayed e.g if it is an encounter search, it should be an encounter list
- searchPhrase: string The phrase to be set in the search box so that a search is triggered on page load to display initial items
- doSearchWhenEmpty: string (default:false): If it is set to true, it lists all items initially and filters them with the given search phrase.
- verboseHandler: function to be called to return the text to display as verbose output