How to get total hits in Lucene Query in GraphQL

[aminmohammadi05]

I have this Schema

{
    "type": "ContentItem/Product"
}

And this query to fetch Product content items

{
  "from" : {{ from }}, "size" : {{ size }},
  "query": {
    "bool" : {
      "must" : [
        { "term" : { "Content.ContentItem.ContentType" : "Product" }},        
       { "term" : { "Content.ContentItem.Published" : "true" }},
        { "term" : { "Content.ContentItem.Latest" : "true" }},
        { "term" : { "LocalizationPart.Culture" : "{{culture}}" }},
        {
          "bool": {
            "must": [              
              { "match" : { "Content.ContentItem.FullText" : "{{ fulltext }}"}}
            ]
          }
        },
        
        {% if owner != "" and owner != null and owner != '*' %}
        { "term" : { "Content.ContentItem.Owner" : "{{ owner }}" } }
        {% endif %}
        {% if author != "" and author != null and author != '*' %}
        { "term" : { "Content.ContentItem.Author" : "{{ author }}" } }
        {% endif %}
      ]
    }
  },
  "sort": [
    { "Content.ContentItem.ModifiedUtc": { "order": "desc" } },
    { "Content.ContentItem.CreatedUtc": { "order": "desc" } }
  ]
}

How can I get total hits of this query?

[zyr2288]

In this version (2.1.6), you have to write some code in core.

In File

OrchardCore/src/OrchardCore.Modules/OrchardCore.Search.Lucene/GraphQL/LuceneQueryFieldTypeProvider.cs

Lines 72 to 81 in 208107c

	if (query.ReturnContentItems &&
	type.StartsWith("ContentItem/", StringComparison.OrdinalIgnoreCase))
	{
	var contentType = type.Remove(0, 12);
	fieldType = BuildContentTypeFieldType(schema, contentType, query, fieldTypeName);
	}
	else
	{
	fieldType = BuildSchemaBasedFieldType(query, querySchema, fieldTypeName);
	}

I add this

if (query.ReturnContentItems &&
    type.StartsWith("ContentItem/", StringComparison.OrdinalIgnoreCase))
{

    var hasTotal = querySchema["hasTotal"].GetValue<bool>();
    var contentType = type.Remove(0, 12);
    if (hasTotal)
    {
        fieldType = BuildTotalContentTypeFieldType(schema, contentType, query, fieldTypeName);
    }
    else
    {
        fieldType = BuildContentTypeFieldType(schema, contentType, query, fieldTypeName);
    }
}
else
{
    fieldType = BuildSchemaBasedFieldType(query, querySchema, fieldTypeName);
}

Change schema

{
    "type": "ContentItem/Product",
    "hasTotal": true
}

Add this function

private FieldType BuildTotalContentTypeFieldType(ISchema schema, string contentType, Query query, string fieldTypeName)
{
    var typeType = schema.Query.Fields.OfType<ContentItemsFieldType>().FirstOrDefault(x => x.Name == contentType);

    if (typeType == null)
        return null;

    var totalType = new ObjectGraphType<LuceneQueryResults>
    {
        Name = fieldTypeName,
    };

    var items = new FieldType
    {
        Name = "items",
        Type = typeType.Type,
        ResolvedType = typeType.ResolvedType,
        Resolver = new LockedAsyncFieldResolver<LuceneQueryResults, object>(async (context) =>
        {
            return context.Source?.Items ?? Array.Empty<object>();
        }),
    };
    totalType.AddField(items);

    var count = totalType.Field("count", typeof(IntGraphType));
    count.Resolve(new LockedAsyncFieldResolver<LuceneQueryResults, object>(async (context) =>
    {
        return context.Source?.Count ?? 0;
    }));

    var fieldType = new FieldType
    {
        Arguments = new QueryArguments(
            new QueryArgument<StringGraphType> { Name = "parameters" }
        ),
        Name = fieldTypeName,
        Description = S["Represents the {0} Query : {1}", query.Source, query.Name],
        ResolvedType = totalType,
        Resolver = new LockedAsyncFieldResolver<object, object>(ResolveAsync),
        Type = totalType.GetType()
    };

    async ValueTask<object> ResolveAsync(IResolveFieldContext<object> context)
    {
        var queryManager = context.RequestServices.GetRequiredService<IQueryManager>();

        var iQuery = await queryManager.GetQueryAsync(query.Name);

        var parameters = context.GetArgument<string>("parameters");

        var queryParameters = parameters != null
            ? JConvert.DeserializeObject<Dictionary<string, object>>(parameters)
            : [];

        var result = await queryManager.ExecuteQueryAsync(iQuery, queryParameters);

        return result;
    }

    return fieldType;
}