Elasticsearch search templates - json

Question

I tried using ES's search template to do a conditional clause as specified here. I'm sending my request to the /[my_index]/_search/template endpoint. The request fails because of JSON parsing issues, which makes sense because after adding the conditional clause the payload is no longer a valid JSON. How than am I supposed to use the search templates? Is there a designated endpoint for non-JSON templates?

Answer 1

When using conditional clauses,the template will not be a valid JSON because it will include the section markers {{# like this }}.For this reason, the template should either be stored in a file or, when used via the REST API, should be written as a string.
Method 1 : tempalte stored in a file
Save the query part of the template in config/scripts
ES installation>Config>scripts
test_template.mustache
{
"query":{ whatever query }
}
you can use the saved template by this method through sense
GET /_search/template
{
"template": "test_template",
"params": {
whatever params
}
}
Method 2: template written as a string
convert the template to string form and use via rest api
POST /_search/template/test_template
{
"template": "{\"query\":{ whatever query; remember to escape quotes}}"
}
To search using this template,
GET /_search/template
{
"template": {
"id": "test_template"
},
"params": {
whatever params
}
}
Reference: https://www.elastic.co/guide/en/elasticsearch/reference/1.7/search-template.html#_conditional_clauses

Answer 2

You need to escape the template in wrapping string.
From the same link you referenced:
As written above, this template is not valid JSON because it includes
the section markers like {{#line_no}}. For this reason, the template
should either be stored in a file (see the section called
“Pre-registered templateedit”) or, when used via the REST API, should
be written as a string:
"template":
"{\"query\":{\"filtered\":{\"query\":{\"match\":{\"line\":\"{{text}}\"}},\"filter\":{{{#line_no}}\"range\":{\"line_no\":{{{#start}}\"gte\":\"{{start}}\"{{#end}},{{/end}}{{/start}}{{#end}}\"lte\":\"{{end}}\"{{/end}}}}{{/line_no}}}}}}"