GSP rendering programmatically

Suppose I have a gsp snippet stored in my database. How do I programmatically merge it with a 开发者_如何学Pythondata model to produce a string.

---

The applicationContext of any Grails app contains a bean named

groovyPagesTemplateEngine

By default this is a instance of GroovyPagesTemplateEngine. So you might use code like this in your controller or service:

class MyService/MyController {
    def groovyPagesTemplateEngine

    String renderGSPToString(String uri, Map model) {
        groovyPagesTemplateEngine.createTemplate(uri).make(model).toString()
    }
}

NB: this snippet is not really taken from running code, it should just clarify the idea.

---

I found a DIRTY (but working) way of rendering complex gsps offline using groovyPageRenderer with substituted scriptsource. In that case you have access to all gsp syntax including g:if etc..

First define two dummy classes:

class StringPageLocator extends GrailsConventionGroovyPageLocator {
    GroovyPageScriptSource findViewByPath(String content) {
        return new StringScriptSource(content)
    }
}

class StringScriptSource implements GroovyPageScriptSource{

    String content

    public StringScriptSource(String content) {
        this.content=content
    }

    @Override String suggestedClassName() { "DummyName" }
    @Override boolean isPublic() { true }
    @Override String getScriptAsString() { return content }
    @Override boolean isModified() { true }
    @Override String getURI() { "DummyURI" }
}

And then you can use it as such:

def groovyPageLocator // Injected automaticaly to service/controller etc...

groovyPageRenderer.groovyPageLocator=new StringPageLocator()
String output=groovyPageRenderer.render(
    view:'Hello2 ${user} <g:if test="${test}">TRUE!!!</g:if>',
    model:[user:'test user2',test:true]

)

---

You can make a controller method that does what you want. Then you will have an HTTP api to accomplish what you want. The controller method's template will have a <g:render> tag, appropriately parameterized.